https://uhm.vn/forum/ Wed, 15 Apr 2026 23:10:34 +0000 MyBB https://uhm.vn/forum/Thread-Women-s-Dresses--354555 Fri, 22 Oct 2021 12:11:48 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-Women-s-Dresses--354555
    Women's dresses had gone to great extremes in the 1920s, with very short hemlines and boyish styles. The change in dress styles in the 1930s was thus very dramatic, for the decade saw a return to femininity and distinct changes in cut and hemline. The depressed economic circumstances of the decade and later of the war years required simplicity in dress styles, but talented designers turned these constraints to their advantage, making slim-fitting but stylish dresses in a variety of styles.

    Perhaps the single biggest change in the 1930s was the lengthening of the hemline, which fell to mid-calf for day wear and to the floor for evening wear. Silk Dresses were tube-shaped and very sleek, fitting closely through the torso and lacking billows or pleats in the skirt. Dressmakers achieved a flowing look either by using newer fabrics like rayon or by cutting fabrics diagonal to the direction of the weave, called a bias cut. Waists in general were tucked in closely, and the waistline was often accented with a belt. Late in the 1930s the desire for a very small waist led to the reappearance of the corset, a confining undergarment that had gone out of style in the 1910s. Wartime dress restrictions soon put an end to this fashion revival, however, much to the pleasure of women who did not want to see the return of the uncomfortable corset.

    Several elements of 1930s and early 1940s dress styles are especially distinctive. The first was the treatment of the back and buttocks. Many dresses were made to reveal large portions of the back, with great Vs that reached nearly to the waist, meaning the top neckline of the dress plunged down to the waist in the back creating a V shape. Long Dresses were also fitted very closely across the buttocks, marking the first time in history the true shape of women's rears were made a focus of attention. These styles were particularly visible in evening wear.

    Women's sleepwear is also called nightdress, nightclothes, or nightwear. It is a clothing created for sleeping purposes. It is worn by women who really feel comfortable with it because some would rather prefer to sleep naked or only in a particular type of underwear. The type of nightwear being may also depend on the season. Take for instance; some women are wearing nightdresses only on winter. But now, using it is another way of following the latest trends in fashion. There are several types of women's sleepwear and each has specific features that will cater to the different preferences, styles, and needs of every woman. Take enough time in educating yourself with various styles and get inspiration from its different looks and appeal so that you can create your own fashion statement.


    - A Sleepwear Set which is really intended for women is a babydoll, popularly known as negligee or short nightgown. The garment is usually trimmed with ruffles, lace, appliques, ribbons, bows, and Marabou fur which can be designed optionally with spaghetti straps. The materials used are either translucent fabrics (silk, chiffon, or nylon) or sheer. A babydoll is considered a provocative dress resembling minidresses that have six inches hemline above the knees and hollow designs on the necks.


    - The most popular loosely designed night apparel for women is a nightgown or nightie which is made of materials such as nylon, satin, silk, and cotton. Its length may vary. It can either be a hip-length or a floor-length nightgown. However, the usual length is knee length. A nightgown can be decorated with embroidery and lace appliqus on the hemlines and cups.


    - The women's Knitted Sleepwear which is only intended for bedroom and night use is the negligee. It was introduced during the eighteenth century in France where it copied the designs of the day dresses of women at that time. However, the alteration of its designs with lace trimming, bows, and translucent bodices lead to considering it as lingerie. The modern designs revealed fabrics sewn in multiple layers giving a more fine emphasis on women's bed-capes and bedjackets.

    Once upon a time, your gender determined your fashion choices. For most of the last few hundred years in the Western world, women wore dresses and skirts, and men wore pants. Except for the Scots. Thankfully, fashion has evolved such that both men and women are now free to wear anything they please, although it’s still suggested to take fashion tips from personal stylists.


    There are a few gendered fashion trends that persist, however, and it is one that makes women’s dressing just a little more difficult than it needs to be: buttons! Buttons appear on different sides of a shirt or jacket depending on which gender it was designed for. Despite the fact that the vast majority of all humans are right-handed, only men's shirts have buttons on the right side. Women's Blouses And Shirts have buttons on the left side. Great for lefties, but an extra couple of minutes in the morning for everyone else.


    It seems particularly absurd given the relative similarity in the shape of men’s and women’s shirts. Sure, there might be a little extra tailoring to account for some generalized curves, but the humble button-up shirt is one of the more unisex items of clothing regularly worn by both sexes. A good shirt can even help you dress to look younger.

    Silk is natural Apparel Fabrics known for its luster, shine, strength, and durability, and it has a long trading history across the world. Silk is the epitome of luxury due to its high cost to produce, soft feel, and elegant appearance, and it is thus a popular textile in high-end and couture fashion design.


    Silk is a natural fiber produced by insects as a material for their nests and cocoons. There are several types of insects that produce Silk Woven Fabric, including silkworms (the most common type of silk), beetles, honey bees, bumble bees, hornets, weaver ants, and many more. Made primarily of a protein called fibroin, silk is known for its shine and softness as a material.


    The history of silk roots in China, where the production of the textile was kept as a secret for over 2,000 years. The origins of silk dates back to the Chinese neolithic era as the oldest silk example found has been dated to 3630 BC.


    Today, the main countries involved in the production of silk are China, India, Uzbekistan, Brazil, Japan, Thailand, Vietnam and Iran. Despite the small market share of silk in the Global Textile Market (around 0.2%), the production is spread around 60 countries all over the world.


    China is the world’s biggest producer and main global supplier of silk, followed by India. The silk production process is called Sericulture. It begins with the cultivation of silkworms which, despite their name, aren't actually worms but larvae that would turn into moths.]]>
    Women's dresses had gone to great extremes in the 1920s, with very short hemlines and boyish styles. The change in dress styles in the 1930s was thus very dramatic, for the decade saw a return to femininity and distinct changes in cut and hemline. The depressed economic circumstances of the decade and later of the war years required simplicity in dress styles, but talented designers turned these constraints to their advantage, making slim-fitting but stylish dresses in a variety of styles.

    Perhaps the single biggest change in the 1930s was the lengthening of the hemline, which fell to mid-calf for day wear and to the floor for evening wear. Silk Dresses were tube-shaped and very sleek, fitting closely through the torso and lacking billows or pleats in the skirt. Dressmakers achieved a flowing look either by using newer fabrics like rayon or by cutting fabrics diagonal to the direction of the weave, called a bias cut. Waists in general were tucked in closely, and the waistline was often accented with a belt. Late in the 1930s the desire for a very small waist led to the reappearance of the corset, a confining undergarment that had gone out of style in the 1910s. Wartime dress restrictions soon put an end to this fashion revival, however, much to the pleasure of women who did not want to see the return of the uncomfortable corset.

    Several elements of 1930s and early 1940s dress styles are especially distinctive. The first was the treatment of the back and buttocks. Many dresses were made to reveal large portions of the back, with great Vs that reached nearly to the waist, meaning the top neckline of the dress plunged down to the waist in the back creating a V shape. Long Dresses were also fitted very closely across the buttocks, marking the first time in history the true shape of women's rears were made a focus of attention. These styles were particularly visible in evening wear.

    Women's sleepwear is also called nightdress, nightclothes, or nightwear. It is a clothing created for sleeping purposes. It is worn by women who really feel comfortable with it because some would rather prefer to sleep naked or only in a particular type of underwear. The type of nightwear being may also depend on the season. Take for instance; some women are wearing nightdresses only on winter. But now, using it is another way of following the latest trends in fashion. There are several types of women's sleepwear and each has specific features that will cater to the different preferences, styles, and needs of every woman. Take enough time in educating yourself with various styles and get inspiration from its different looks and appeal so that you can create your own fashion statement.


    - A Sleepwear Set which is really intended for women is a babydoll, popularly known as negligee or short nightgown. The garment is usually trimmed with ruffles, lace, appliques, ribbons, bows, and Marabou fur which can be designed optionally with spaghetti straps. The materials used are either translucent fabrics (silk, chiffon, or nylon) or sheer. A babydoll is considered a provocative dress resembling minidresses that have six inches hemline above the knees and hollow designs on the necks.


    - The most popular loosely designed night apparel for women is a nightgown or nightie which is made of materials such as nylon, satin, silk, and cotton. Its length may vary. It can either be a hip-length or a floor-length nightgown. However, the usual length is knee length. A nightgown can be decorated with embroidery and lace appliqus on the hemlines and cups.


    - The women's Knitted Sleepwear which is only intended for bedroom and night use is the negligee. It was introduced during the eighteenth century in France where it copied the designs of the day dresses of women at that time. However, the alteration of its designs with lace trimming, bows, and translucent bodices lead to considering it as lingerie. The modern designs revealed fabrics sewn in multiple layers giving a more fine emphasis on women's bed-capes and bedjackets.

    Once upon a time, your gender determined your fashion choices. For most of the last few hundred years in the Western world, women wore dresses and skirts, and men wore pants. Except for the Scots. Thankfully, fashion has evolved such that both men and women are now free to wear anything they please, although it’s still suggested to take fashion tips from personal stylists.


    There are a few gendered fashion trends that persist, however, and it is one that makes women’s dressing just a little more difficult than it needs to be: buttons! Buttons appear on different sides of a shirt or jacket depending on which gender it was designed for. Despite the fact that the vast majority of all humans are right-handed, only men's shirts have buttons on the right side. Women's Blouses And Shirts have buttons on the left side. Great for lefties, but an extra couple of minutes in the morning for everyone else.


    It seems particularly absurd given the relative similarity in the shape of men’s and women’s shirts. Sure, there might be a little extra tailoring to account for some generalized curves, but the humble button-up shirt is one of the more unisex items of clothing regularly worn by both sexes. A good shirt can even help you dress to look younger.

    Silk is natural Apparel Fabrics known for its luster, shine, strength, and durability, and it has a long trading history across the world. Silk is the epitome of luxury due to its high cost to produce, soft feel, and elegant appearance, and it is thus a popular textile in high-end and couture fashion design.


    Silk is a natural fiber produced by insects as a material for their nests and cocoons. There are several types of insects that produce Silk Woven Fabric, including silkworms (the most common type of silk), beetles, honey bees, bumble bees, hornets, weaver ants, and many more. Made primarily of a protein called fibroin, silk is known for its shine and softness as a material.


    The history of silk roots in China, where the production of the textile was kept as a secret for over 2,000 years. The origins of silk dates back to the Chinese neolithic era as the oldest silk example found has been dated to 3630 BC.


    Today, the main countries involved in the production of silk are China, India, Uzbekistan, Brazil, Japan, Thailand, Vietnam and Iran. Despite the small market share of silk in the Global Textile Market (around 0.2%), the production is spread around 60 countries all over the world.


    China is the world’s biggest producer and main global supplier of silk, followed by India. The silk production process is called Sericulture. It begins with the cultivation of silkworms which, despite their name, aren't actually worms but larvae that would turn into moths.]]> https://uhm.vn/forum/Thread-Does-farrowing-crate-size-impact-piglet-survival--354554 Fri, 22 Oct 2021 12:10:13 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-Does-farrowing-crate-size-impact-piglet-survival--354554
    Reminiscing back to my familys 50-head pure-line sow herd in the 1980s, I recall we on occasion had a sow that barely fit into the farrowing Pig Crate. I can remember a particularly large Landrace sow, as wide and as long as the crate, that appeared quite uncomfortable. She ended up laying on multiple piglets.

    I'm sure some of you may share a similar story. Now fast forward to 2020. One would think we would have the optimal farrowing crate size figured out. Yet I am not sure we do. There are around one million farrowing crates in the United States, and Tube Farrowing Crates are a sizable capital expense. Yet studying differences between farrowing crates can be challenging.

    When evaluating different farrowing crates, generally each design or size should be represented within the same room. To further complicate things, research for piglet survival requires hundreds of replicates per treatment to achieve adequate statistical power.

    Farrowing crate width

    Farrowing crate width has not been shown to greatly impact piglet survival in large commercial studies. Ketchem and Rix (2013) evaluated three farrowing crate types where the sowing area was similar in length, yet some differences existed in width. In general, Solid Rod Farrowing Stalls width of 17 and 20 inches did not appear to greatly impact piglet survival. Keeping the sowing area the same, Vande Pol (2017) evaluated farrowing crate width using over 1,600 litters. The author reported no statistical differences for preweaning mortality between farrowing crate widths of 60 and 66 inches (15.2% vs. 14.6%, respectively).

    Farrowing crate length

    There is anecdotal evidence that farrowing crate length impacts piglet survival, perhaps more so for longer, heavier sows. We recently analyzed data from a commercial sow farm in eastern North Carolina with which we collaborate. The farm expanded in size over time and has three different Solid Rod Gestation Stalls sizes.

    Do longer sows wean fewer piglets?

    While interactions between farrowing crate length with sow length and sow weight remain to be validated, evidence of sows being too long comes from a 2009 Pork Checkoff study. The study scored gilts for body length 1 (short) to 9 (long) at the selection and followed the gilts through multiple parties. Gilts that were longer at selection subsequently had reduced piglet survival as sows.

    How do I keep my sows from becoming too big for my farrowing crates? There are multiple strategies that can be utilized to prevent large sows. Please refer to past articles addressing strategies to reduce sow size through genetics, managing gilt weight at breeding and body condition management.

    Going forward

    Perhaps the data presented in this article suggest more research is needed to determine optimal farrowing crate size in relation to reproductive throughput.

    Mother pigs have an instinct to love, protect, and nurture their newborn babies, just like humans do. However, the meat industry doesn’t see female pigs as mothers with the capacity to love. Instead, they treat mother female pigs, known as sows, like breeding machines. Pork producers keep their sows in tight Tube Gestation Crates throughout their lives, artificially impregnate them over and over, and take away their piglets at just a few weeks old. To keep up with the demand for pig flesh, female pigs must be forced to continually pump out piglets. Sows, as these mothers are called, are among the most abused animals on the planet thanks to the conditions in which they are kept.]]>
    Reminiscing back to my familys 50-head pure-line sow herd in the 1980s, I recall we on occasion had a sow that barely fit into the farrowing Pig Crate. I can remember a particularly large Landrace sow, as wide and as long as the crate, that appeared quite uncomfortable. She ended up laying on multiple piglets.

    I'm sure some of you may share a similar story. Now fast forward to 2020. One would think we would have the optimal farrowing crate size figured out. Yet I am not sure we do. There are around one million farrowing crates in the United States, and Tube Farrowing Crates are a sizable capital expense. Yet studying differences between farrowing crates can be challenging.

    When evaluating different farrowing crates, generally each design or size should be represented within the same room. To further complicate things, research for piglet survival requires hundreds of replicates per treatment to achieve adequate statistical power.

    Farrowing crate width

    Farrowing crate width has not been shown to greatly impact piglet survival in large commercial studies. Ketchem and Rix (2013) evaluated three farrowing crate types where the sowing area was similar in length, yet some differences existed in width. In general, Solid Rod Farrowing Stalls width of 17 and 20 inches did not appear to greatly impact piglet survival. Keeping the sowing area the same, Vande Pol (2017) evaluated farrowing crate width using over 1,600 litters. The author reported no statistical differences for preweaning mortality between farrowing crate widths of 60 and 66 inches (15.2% vs. 14.6%, respectively).

    Farrowing crate length

    There is anecdotal evidence that farrowing crate length impacts piglet survival, perhaps more so for longer, heavier sows. We recently analyzed data from a commercial sow farm in eastern North Carolina with which we collaborate. The farm expanded in size over time and has three different Solid Rod Gestation Stalls sizes.

    Do longer sows wean fewer piglets?

    While interactions between farrowing crate length with sow length and sow weight remain to be validated, evidence of sows being too long comes from a 2009 Pork Checkoff study. The study scored gilts for body length 1 (short) to 9 (long) at the selection and followed the gilts through multiple parties. Gilts that were longer at selection subsequently had reduced piglet survival as sows.

    How do I keep my sows from becoming too big for my farrowing crates? There are multiple strategies that can be utilized to prevent large sows. Please refer to past articles addressing strategies to reduce sow size through genetics, managing gilt weight at breeding and body condition management.

    Going forward

    Perhaps the data presented in this article suggest more research is needed to determine optimal farrowing crate size in relation to reproductive throughput.

    Mother pigs have an instinct to love, protect, and nurture their newborn babies, just like humans do. However, the meat industry doesn’t see female pigs as mothers with the capacity to love. Instead, they treat mother female pigs, known as sows, like breeding machines. Pork producers keep their sows in tight Tube Gestation Crates throughout their lives, artificially impregnate them over and over, and take away their piglets at just a few weeks old. To keep up with the demand for pig flesh, female pigs must be forced to continually pump out piglets. Sows, as these mothers are called, are among the most abused animals on the planet thanks to the conditions in which they are kept.]]> https://uhm.vn/forum/Thread-Does-farrowing-crate-size-impact-piglet-survival--354553 Fri, 22 Oct 2021 12:09:28 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-Does-farrowing-crate-size-impact-piglet-survival--354553
    Reminiscing back to my familys 50-head pure-line sow herd in the 1980s, I recall we on occasion had a sow that barely fit into the farrowing Pig Crate. I can remember a particularly large Landrace sow, as wide and as long as the crate, that appeared quite uncomfortable. She ended up laying on multiple piglets.

    I'm sure some of you may share a similar story. Now fast forward to 2020. One would think we would have the optimal farrowing crate size figured out. Yet I am not sure we do. There are around one million farrowing crates in the United States, and Tube Farrowing Crates are a sizable capital expense. Yet studying differences between farrowing crates can be challenging.

    When evaluating different farrowing crates, generally each design or size should be represented within the same room. To further complicate things, research for piglet survival requires hundreds of replicates per treatment to achieve adequate statistical power.

    Farrowing crate width

    Farrowing crate width has not been shown to greatly impact piglet survival in large commercial studies. Ketchem and Rix (2013) evaluated three farrowing crate types where the sowing area was similar in length, yet some differences existed in width. In general, Solid Rod Farrowing Stalls width of 17 and 20 inches did not appear to greatly impact piglet survival. Keeping the sowing area the same, Vande Pol (2017) evaluated farrowing crate width using over 1,600 litters. The author reported no statistical differences for preweaning mortality between farrowing crate widths of 60 and 66 inches (15.2% vs. 14.6%, respectively).

    Farrowing crate length

    There is anecdotal evidence that farrowing crate length impacts piglet survival, perhaps more so for longer, heavier sows. We recently analyzed data from a commercial sow farm in eastern North Carolina with which we collaborate. The farm expanded in size over time and has three different Solid Rod Gestation Stalls sizes.

    Do longer sows wean fewer piglets?

    While interactions between farrowing crate length with sow length and sow weight remain to be validated, evidence of sows being too long comes from a 2009 Pork Checkoff study. The study scored gilts for body length 1 (short) to 9 (long) at the selection and followed the gilts through multiple parties. Gilts that were longer at selection subsequently had reduced piglet survival as sows.

    How do I keep my sows from becoming too big for my farrowing crates? There are multiple strategies that can be utilized to prevent large sows. Please refer to past articles addressing strategies to reduce sow size through genetics, managing gilt weight at breeding and body condition management.

    Going forward

    Perhaps the data presented in this article suggest more research is needed to determine optimal farrowing crate size in relation to reproductive throughput.

    Mother pigs have an instinct to love, protect, and nurture their newborn babies, just like humans do. However, the meat industry doesn’t see female pigs as mothers with the capacity to love. Instead, they treat mother female pigs, known as sows, like breeding machines. Pork producers keep their sows in tight Tube Gestation Crates throughout their lives, artificially impregnate them over and over, and take away their piglets at just a few weeks old. To keep up with the demand for pig flesh, female pigs must be forced to continually pump out piglets. Sows, as these mothers are called, are among the most abused animals on the planet thanks to the conditions in which they are kept.]]>
    Reminiscing back to my familys 50-head pure-line sow herd in the 1980s, I recall we on occasion had a sow that barely fit into the farrowing Pig Crate. I can remember a particularly large Landrace sow, as wide and as long as the crate, that appeared quite uncomfortable. She ended up laying on multiple piglets.

    I'm sure some of you may share a similar story. Now fast forward to 2020. One would think we would have the optimal farrowing crate size figured out. Yet I am not sure we do. There are around one million farrowing crates in the United States, and Tube Farrowing Crates are a sizable capital expense. Yet studying differences between farrowing crates can be challenging.

    When evaluating different farrowing crates, generally each design or size should be represented within the same room. To further complicate things, research for piglet survival requires hundreds of replicates per treatment to achieve adequate statistical power.

    Farrowing crate width

    Farrowing crate width has not been shown to greatly impact piglet survival in large commercial studies. Ketchem and Rix (2013) evaluated three farrowing crate types where the sowing area was similar in length, yet some differences existed in width. In general, Solid Rod Farrowing Stalls width of 17 and 20 inches did not appear to greatly impact piglet survival. Keeping the sowing area the same, Vande Pol (2017) evaluated farrowing crate width using over 1,600 litters. The author reported no statistical differences for preweaning mortality between farrowing crate widths of 60 and 66 inches (15.2% vs. 14.6%, respectively).

    Farrowing crate length

    There is anecdotal evidence that farrowing crate length impacts piglet survival, perhaps more so for longer, heavier sows. We recently analyzed data from a commercial sow farm in eastern North Carolina with which we collaborate. The farm expanded in size over time and has three different Solid Rod Gestation Stalls sizes.

    Do longer sows wean fewer piglets?

    While interactions between farrowing crate length with sow length and sow weight remain to be validated, evidence of sows being too long comes from a 2009 Pork Checkoff study. The study scored gilts for body length 1 (short) to 9 (long) at the selection and followed the gilts through multiple parties. Gilts that were longer at selection subsequently had reduced piglet survival as sows.

    How do I keep my sows from becoming too big for my farrowing crates? There are multiple strategies that can be utilized to prevent large sows. Please refer to past articles addressing strategies to reduce sow size through genetics, managing gilt weight at breeding and body condition management.

    Going forward

    Perhaps the data presented in this article suggest more research is needed to determine optimal farrowing crate size in relation to reproductive throughput.

    Mother pigs have an instinct to love, protect, and nurture their newborn babies, just like humans do. However, the meat industry doesn’t see female pigs as mothers with the capacity to love. Instead, they treat mother female pigs, known as sows, like breeding machines. Pork producers keep their sows in tight Tube Gestation Crates throughout their lives, artificially impregnate them over and over, and take away their piglets at just a few weeks old. To keep up with the demand for pig flesh, female pigs must be forced to continually pump out piglets. Sows, as these mothers are called, are among the most abused animals on the planet thanks to the conditions in which they are kept.]]> https://uhm.vn/forum/Thread-Offset-Printing-Heat-Transfer-Ink-How-to-Prevent-Layout-Dirty--354550 Fri, 22 Oct 2021 12:07:38 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-Offset-Printing-Heat-Transfer-Ink-How-to-Prevent-Layout-Dirty--354550
    The principle of sublimation Offset Heat Transfer ink balance is minimizing the amount of wetting liquid in advance of layout is not dirty. Many dynamic variables in the printing process changes are easily lead to ink balance broken. The offset printing machine operator needs to actively check, prevent scrumming. Layout priority detection should be the most easily strumming parts:

    a. Small white text and lines turn to be dirty easily, especially when the plate no level. b. The darkened part of the level version is easy to paste off. c. The plate edges are more easily dirty due to their position.

    What is said above is mainly aimed at some problems that should be paid attention to the assessment of vision. The qualified factory should check together with control strips and instrument checks to achieve the best effect. The control strip has the function of amplifying for this imperceptible printing fault visually, but placing the control strip must use larger paper, which increases the production cost. The density and chromaticity detection is not affected by the environment and subjective factors, and the results are more objective in terms of value, which is an indispensable standard production tool. The measurement sensitivity of dark parts by density meter is superior to the visual assessment of ink of the deep parts of the light. Therefore, when printing light color field, it is mainly based on the visual evaluation. While printing a dark color field, try to use a density meter to detect auxiliary.

    Flock is a unique heat transfer vinyl that gives your design an added dimension given a raised, soft, and textured suede/velvet feel that is a perfect alternative to embroidery. This makes it great for children's garments (ex. onesies) as well as adults (ex. team sweatshirts).


    Whether you’re looking for that alternative to embroidery or going for a retro look, flock can help you achieve this. Siser StripFlock, as well as Chemical UpperFlock, can even be layered on top of itself! With a wide offering of colors, you’re sure to find the perfect shade to complement any design for children or adults.


    Flock Heat Transfer is a non-permanent flocked paper for producing single colour flock transfers. Transflock is distinguished by a constant and dense flocking and a uniform length of flock fibers. Designs can be transferred without leaving any unwanted flock fibers on the textile.


    Sublimation Transfer For Clothes is an indirect printing process. Using sublimation ink-jet inks the image is printed on a special transfer paper and, with heat, the image is transferred to the fabric. The term sublimation describes the direct transition from a solid to a gaseous state – this happens without the usual in-between liquid state. When heat is used for this process, one refers to thermosublimation. This is a process that has been being used for a long time in the textile industry. The actual process starts with the printing of a preferably cheap, special paper. Until recently this was done using traditional gravure printing – simple transfer papers printed with standard printing patterns and graphical elements.

    Reflective Heat Transfer Printing is the process of combining heat with a transfer medium to create personalized T Shirts or merchandise. Transfer medium comes in the form of vinyl (a coloured rubber material) and transfers paper (a wax and pigment coated paper). Heat transfer vinyl comes in various colors and patterns, from solid colors to even reflective materials and glitter materials. It is most commonly used to customize names and numbers on jerseys. Transfer paper has no limiations to colors and designs. Individual artwork or images can be printed onto the medium with an inkjet printer to create shirts with your design! To finish off, vinyl or transfer papers are in a cutter or plotter machine to cut the design’s shape and transferred onto a T-Shirt using a heat press machine.

    Advantages of Sublimation Heat Transfer printing:

    – Allows for different customization for every piece e.g. name customization

    – Shorter lead time for smaller quantity orders

    – Cost-efficient for small quantity orders

    – Able to produce high quality and complex graphics with unlimited options

    Heat Transfer Printing For Leather was introduced by John Sadler and Guy Greenway back in the 1750s. The technique was first developed to decorate ceramics, mainly pottery. The technique was well accepted and it quickly spread to other parts of Europe.


    Back then, the process involved a metal plate engraved with decorative elements. The plate would be covered in ink and pressed or rolled over the ceramic. The process was slow and tedious compared to modern-day transfer printing, but it was still way quicker than hand painting on ceramic. Later in the late 1940s, thermal transfer printing (a technique more commonly used today) was invented by a corporation called SATO, based in the US.]]>
    The principle of sublimation Offset Heat Transfer ink balance is minimizing the amount of wetting liquid in advance of layout is not dirty. Many dynamic variables in the printing process changes are easily lead to ink balance broken. The offset printing machine operator needs to actively check, prevent scrumming. Layout priority detection should be the most easily strumming parts:

    a. Small white text and lines turn to be dirty easily, especially when the plate no level. b. The darkened part of the level version is easy to paste off. c. The plate edges are more easily dirty due to their position.

    What is said above is mainly aimed at some problems that should be paid attention to the assessment of vision. The qualified factory should check together with control strips and instrument checks to achieve the best effect. The control strip has the function of amplifying for this imperceptible printing fault visually, but placing the control strip must use larger paper, which increases the production cost. The density and chromaticity detection is not affected by the environment and subjective factors, and the results are more objective in terms of value, which is an indispensable standard production tool. The measurement sensitivity of dark parts by density meter is superior to the visual assessment of ink of the deep parts of the light. Therefore, when printing light color field, it is mainly based on the visual evaluation. While printing a dark color field, try to use a density meter to detect auxiliary.

    Flock is a unique heat transfer vinyl that gives your design an added dimension given a raised, soft, and textured suede/velvet feel that is a perfect alternative to embroidery. This makes it great for children's garments (ex. onesies) as well as adults (ex. team sweatshirts).


    Whether you’re looking for that alternative to embroidery or going for a retro look, flock can help you achieve this. Siser StripFlock, as well as Chemical UpperFlock, can even be layered on top of itself! With a wide offering of colors, you’re sure to find the perfect shade to complement any design for children or adults.


    Flock Heat Transfer is a non-permanent flocked paper for producing single colour flock transfers. Transflock is distinguished by a constant and dense flocking and a uniform length of flock fibers. Designs can be transferred without leaving any unwanted flock fibers on the textile.


    Sublimation Transfer For Clothes is an indirect printing process. Using sublimation ink-jet inks the image is printed on a special transfer paper and, with heat, the image is transferred to the fabric. The term sublimation describes the direct transition from a solid to a gaseous state – this happens without the usual in-between liquid state. When heat is used for this process, one refers to thermosublimation. This is a process that has been being used for a long time in the textile industry. The actual process starts with the printing of a preferably cheap, special paper. Until recently this was done using traditional gravure printing – simple transfer papers printed with standard printing patterns and graphical elements.

    Reflective Heat Transfer Printing is the process of combining heat with a transfer medium to create personalized T Shirts or merchandise. Transfer medium comes in the form of vinyl (a coloured rubber material) and transfers paper (a wax and pigment coated paper). Heat transfer vinyl comes in various colors and patterns, from solid colors to even reflective materials and glitter materials. It is most commonly used to customize names and numbers on jerseys. Transfer paper has no limiations to colors and designs. Individual artwork or images can be printed onto the medium with an inkjet printer to create shirts with your design! To finish off, vinyl or transfer papers are in a cutter or plotter machine to cut the design’s shape and transferred onto a T-Shirt using a heat press machine.

    Advantages of Sublimation Heat Transfer printing:

    – Allows for different customization for every piece e.g. name customization

    – Shorter lead time for smaller quantity orders

    – Cost-efficient for small quantity orders

    – Able to produce high quality and complex graphics with unlimited options

    Heat Transfer Printing For Leather was introduced by John Sadler and Guy Greenway back in the 1750s. The technique was first developed to decorate ceramics, mainly pottery. The technique was well accepted and it quickly spread to other parts of Europe.


    Back then, the process involved a metal plate engraved with decorative elements. The plate would be covered in ink and pressed or rolled over the ceramic. The process was slow and tedious compared to modern-day transfer printing, but it was still way quicker than hand painting on ceramic. Later in the late 1940s, thermal transfer printing (a technique more commonly used today) was invented by a corporation called SATO, based in the US.]]> https://uhm.vn/forum/Thread-Reasons-Why-Mobile-Phone-Accessories-Market-is-on-a-Growth-Trajectory--354548 Fri, 22 Oct 2021 12:05:30 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-Reasons-Why-Mobile-Phone-Accessories-Market-is-on-a-Growth-Trajectory--354548
    Telecom Accessories are as important as a mobile phone in day-to-day life. Most of us would find it difficult to survive without a mobile phone and the bare minimum set of accessories. Be it power banks, earphones or smartwatches, these accessories are a must-have these days. Thereby, creating a market that is growing by leaps and bounds year on year and is hard to ignore.

    A recent study on the mobile phone accessories market in India reveals that a rapid increase in sales of mobile accessories is directly proportional to the sale of smartphones in the country. The mobile phone market is expected to grow at a CAGR of 2.6% from the period of 2014 to 2020. Consequently, the Prefromed Dead End accessories market would also continue to grow and is expected to reach $107.3 billion by 2022.

    The population in urban areas is increasing. Spending capacity, too, has increased. With mobile phones becoming an indispensable part of urban life, more and more consumers are spending on smartphones and accessories.

    The influx of e-commerce websites has had a role to play in growing the mobile phone market in India – both by usage and by the sale of mobile phones themselves. While the money muscle of the e-commerce giants was used by them to increase their sales, it had a direct effect on the uptake of smartphones by the Indian buyers. Vertical e-commerce companies focused on the mobile phone Preformed Fittings sector also led to an increase in demand for accessories.

    The Deadend Clamps for ADSS conductors are designed to anchor insulated service lines with 2 or 4 conductors to the pole or wall. The ADSS tension clamp is composed of a body, wedges and removable and adjustable bail or pad. The PA series Anchor clamps are designed to supporting the neutral messenger, the wedge can be self-adjusting. Pilot wires or street lighting conductors are led alongside the clamp. The self-opening is featured by Power Utility Fittings to easily insert the conductor into the clamp.


    Poleline Hardware Fittings are also named pole line accessories or pole hardware fitting, they are important components of the pole line construction. According to the application, it can be divided into telephone pole hardware, utility pole mounting hardware, or utility pole line hardware.


    The pole line hardware is joined together to make the installation come true, it is not only supporting the power line but also protecting the power line from flowing. The full line of the hardware needed for power utility applications includes Anchor Rods, Guy Attachment, pole band,  secondary clevis,  secondary rack, stay rod, street light arm, yoke plate, etc.


    Utility pole mounting hardware is a quality utility power line part and accessories for the electrical market all over the world. For different raw materials, there are different processes. For the angle steel, the process involves cutting, punching, welding, and bending. For the steel rod, the process is hot forged.

    Fiberglass reinforced polymer (FRP) or fiberglass is a composite composed of a polymer resin matrix where glass fibers are embedded to impart reinforcement. The type, quantity, orientation, and location of the glass fibers within a fiberglass component determine its strength.


    The Fiber Glass Products offered by Strongwell are lighter than steel and aluminum by 80% and 30%, respectively. This translates to easier installation, lower transportation, and minimal weight in structural design demanding weight savings. The company continues its efforts to make lighter yet stronger fiberglass.

    The earth anchor is a dump earth anchor, which is used to bear tensile load. The maximum working load of stingray anchor is 35 tons. After driving the anchor to the required depth, remove the driven steel. Then tilt the anchor and lock the load using foresight's anchor lock kit. This provides immediate verification testing for each anchor.


    Earth Anchors are the perfect solution for high bearing capacity applications because they provide superior support for civil construction operations, excavation support and tie back.]]>
    Telecom Accessories are as important as a mobile phone in day-to-day life. Most of us would find it difficult to survive without a mobile phone and the bare minimum set of accessories. Be it power banks, earphones or smartwatches, these accessories are a must-have these days. Thereby, creating a market that is growing by leaps and bounds year on year and is hard to ignore.

    A recent study on the mobile phone accessories market in India reveals that a rapid increase in sales of mobile accessories is directly proportional to the sale of smartphones in the country. The mobile phone market is expected to grow at a CAGR of 2.6% from the period of 2014 to 2020. Consequently, the Prefromed Dead End accessories market would also continue to grow and is expected to reach $107.3 billion by 2022.

    The population in urban areas is increasing. Spending capacity, too, has increased. With mobile phones becoming an indispensable part of urban life, more and more consumers are spending on smartphones and accessories.

    The influx of e-commerce websites has had a role to play in growing the mobile phone market in India – both by usage and by the sale of mobile phones themselves. While the money muscle of the e-commerce giants was used by them to increase their sales, it had a direct effect on the uptake of smartphones by the Indian buyers. Vertical e-commerce companies focused on the mobile phone Preformed Fittings sector also led to an increase in demand for accessories.

    The Deadend Clamps for ADSS conductors are designed to anchor insulated service lines with 2 or 4 conductors to the pole or wall. The ADSS tension clamp is composed of a body, wedges and removable and adjustable bail or pad. The PA series Anchor clamps are designed to supporting the neutral messenger, the wedge can be self-adjusting. Pilot wires or street lighting conductors are led alongside the clamp. The self-opening is featured by Power Utility Fittings to easily insert the conductor into the clamp.


    Poleline Hardware Fittings are also named pole line accessories or pole hardware fitting, they are important components of the pole line construction. According to the application, it can be divided into telephone pole hardware, utility pole mounting hardware, or utility pole line hardware.


    The pole line hardware is joined together to make the installation come true, it is not only supporting the power line but also protecting the power line from flowing. The full line of the hardware needed for power utility applications includes Anchor Rods, Guy Attachment, pole band,  secondary clevis,  secondary rack, stay rod, street light arm, yoke plate, etc.


    Utility pole mounting hardware is a quality utility power line part and accessories for the electrical market all over the world. For different raw materials, there are different processes. For the angle steel, the process involves cutting, punching, welding, and bending. For the steel rod, the process is hot forged.

    Fiberglass reinforced polymer (FRP) or fiberglass is a composite composed of a polymer resin matrix where glass fibers are embedded to impart reinforcement. The type, quantity, orientation, and location of the glass fibers within a fiberglass component determine its strength.


    The Fiber Glass Products offered by Strongwell are lighter than steel and aluminum by 80% and 30%, respectively. This translates to easier installation, lower transportation, and minimal weight in structural design demanding weight savings. The company continues its efforts to make lighter yet stronger fiberglass.

    The earth anchor is a dump earth anchor, which is used to bear tensile load. The maximum working load of stingray anchor is 35 tons. After driving the anchor to the required depth, remove the driven steel. Then tilt the anchor and lock the load using foresight's anchor lock kit. This provides immediate verification testing for each anchor.


    Earth Anchors are the perfect solution for high bearing capacity applications because they provide superior support for civil construction operations, excavation support and tie back.]]> https://uhm.vn/forum/Thread-What-are-the-best-types-of-laser-levels-to-use-in-construction--354546 Fri, 22 Oct 2021 12:03:33 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-What-are-the-best-types-of-laser-levels-to-use-in-construction--354546
    Because there is such a large selection of Laser Levels, it can be hard to know which one is right for you. Line lasers are the most common, because they project a straight-line reference that works both horizontally and vertically. But you can also choose from any of the following:

    Spot Lasers — Project a small circle of light onto a surface on which the laser is focused. This tool is good for making sure a joist or wall is plumb and that pipes moving from one floor to another are also plumb.


    Combination Lasers — Emit both lines and spots either at the same time or independently, which is a great choice if you work on a variety of projects.


    Rotary Lasers — Can be used on almost every type of construction job, from grade work to layout and masonry.


    If you are looking for a self-leveling laser or any other type of laser leveling tool, be sure to look at what we have at Engineering Supply.


    Good laser levels are accurate withing 1/16 of an inch per 100 feet. This is ten times more accurate than a spirit level, which is only 1/2 inch per 100 feet. This 16 Lines Laser Level of precision is made possible through a laser diode that emits a concentrated beam across the area you need to level.


    Cross Line Laser Levels with variable speeds work well for interior work. A variable RPM allows the user to adjust the laser to the speed of best visibility. Slower rotations have a more visible beam. Faster rotations resemble a chalk line. You will want to set the rotation slow enough to where it is just fast enough to be considered a solid line on the wall, as this allows for the best mix of solid and brightness. If you need a solid dot reference set the laser at 0 RPM.

    The laser levels we just discussed are available with varying features. These features may include variable rotation speeds, beam scanning, grade capability, remote controls, rechargeable battery packs, AC chargers and more. Attachments may include a wall/ceiling mount laser platforms, detectors, and trivets for mounting a laser on its side to a tripod for interior work. We recommend you take the time to decide on which jobs or tasks you plan to accomplish while using an 8 Lines Laser Level. Possibly take the time to write these down on paper, then start your search. We recommend that you look over the varying comparison charts for David White, CST/Berger and Pacific Laser Systems Laser Levels as they can quickly point out which units have which features.


    We recommend you take the time to review the varying types of laser level specifications such as the range the laser will emit and accuracy specifications. Working with a construction laser level can save you time and labor while increasing your accuracy. Many setups allow a person to work alone when using a detector on a leveling rod instead of a two-person job with a regular (non-laser) level.

    A Laser Distance Meter sends a pulse of laser light to the target and measures the time it takes for the reflection to
return. For distances up to 30m, the accuracy is é3mm. On-board processing allows the device to add, subtract,
calculate areas and volumes and to triangulate. You can measure distances at a distance.
Compared with a good, old-fashioned tape there is no contest. A Laser Distance Meter wins on every count: speed ,
accuracy, safety, versatility, convenience and functionality.
Ultrasonic devices offer many of the same features but are less accurate.]]>
    Because there is such a large selection of Laser Levels, it can be hard to know which one is right for you. Line lasers are the most common, because they project a straight-line reference that works both horizontally and vertically. But you can also choose from any of the following:

    Spot Lasers — Project a small circle of light onto a surface on which the laser is focused. This tool is good for making sure a joist or wall is plumb and that pipes moving from one floor to another are also plumb.


    Combination Lasers — Emit both lines and spots either at the same time or independently, which is a great choice if you work on a variety of projects.


    Rotary Lasers — Can be used on almost every type of construction job, from grade work to layout and masonry.


    If you are looking for a self-leveling laser or any other type of laser leveling tool, be sure to look at what we have at Engineering Supply.


    Good laser levels are accurate withing 1/16 of an inch per 100 feet. This is ten times more accurate than a spirit level, which is only 1/2 inch per 100 feet. This 16 Lines Laser Level of precision is made possible through a laser diode that emits a concentrated beam across the area you need to level.


    Cross Line Laser Levels with variable speeds work well for interior work. A variable RPM allows the user to adjust the laser to the speed of best visibility. Slower rotations have a more visible beam. Faster rotations resemble a chalk line. You will want to set the rotation slow enough to where it is just fast enough to be considered a solid line on the wall, as this allows for the best mix of solid and brightness. If you need a solid dot reference set the laser at 0 RPM.

    The laser levels we just discussed are available with varying features. These features may include variable rotation speeds, beam scanning, grade capability, remote controls, rechargeable battery packs, AC chargers and more. Attachments may include a wall/ceiling mount laser platforms, detectors, and trivets for mounting a laser on its side to a tripod for interior work. We recommend you take the time to decide on which jobs or tasks you plan to accomplish while using an 8 Lines Laser Level. Possibly take the time to write these down on paper, then start your search. We recommend that you look over the varying comparison charts for David White, CST/Berger and Pacific Laser Systems Laser Levels as they can quickly point out which units have which features.


    We recommend you take the time to review the varying types of laser level specifications such as the range the laser will emit and accuracy specifications. Working with a construction laser level can save you time and labor while increasing your accuracy. Many setups allow a person to work alone when using a detector on a leveling rod instead of a two-person job with a regular (non-laser) level.

    A Laser Distance Meter sends a pulse of laser light to the target and measures the time it takes for the reflection to
return. For distances up to 30m, the accuracy is é3mm. On-board processing allows the device to add, subtract,
calculate areas and volumes and to triangulate. You can measure distances at a distance.
Compared with a good, old-fashioned tape there is no contest. A Laser Distance Meter wins on every count: speed ,
accuracy, safety, versatility, convenience and functionality.
Ultrasonic devices offer many of the same features but are less accurate.]]> https://uhm.vn/forum/Thread-The-Features-of-an-Automatic-Filling-Machine--354543 Fri, 22 Oct 2021 12:01:33 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-The-Features-of-an-Automatic-Filling-Machine--354543
    Overflow fillers, gravity fillers, piston Filling Machines and other liquid fillers all vary in the way that they move product into a bottle or container. However, the automatic versions of these machines almost always have certain features in common. These features are intended to add efficiency, consistency and reliability to the packaging equipment. Below are a few of the most common features of found on Liquid Packaging Solutions' bottle fillers.

    Heavy Duty and Portable Stainless Steel Frame

    For consistent and reliable fills, the Filling Machine must be stabile throughout the process. The heavy duty stainless steel frame protects against shifting, vibrating and other movements that might effect the volume or the level of the fill, while also avoiding splashes and spills. The stainless steel material is compatible with a vast majority of products, though there are exceptions. When corrosive liquids are run on the machinery, other construction materials may be used for the frame, including HDPE. Ultimately, the material used will be that material which will better extend the useful life of the equipment.

    Easy Adjustments From Height to Heads

    Many packagers fill more than a single product, or at the very least fill into bottles of multiple sizes and shapes. Changing over from one product or bottle to another means stopping production on the liquid filler. These machines include simple adjustments to minimize downtime and maximize production. Fill heads can typically be moved using simple fingertip adjustment knobs, while power height comes standard on automatic equipment, allowing up and down movement with the flip of a switch. Even auxillary equipment such as power conveyors include knob adjustments or other simple components for railing and other changes. Other adjustments, such as time and delay settings, can easily be made from the operator control panel, discussed in more detail below.

    PLC with Touch Screen Controls

    Along with easy adjustments to the components of the liquid filler, the Programmable Logic Controller (PLC) and operator interface allow the operators of the equipment to quickly and easily set up indexing times, fill times and other settings for the machinery. The panel allows controls to be centrally located and may also include controls for other equipment such as power conveyors, turntables and more. One of the best features of the PLC is the ability to record recipes for product and bottle combinations. Once all settings have been input for a combination, the combination can be saved and recalled at a later date, making changeover that much easier.

    Capping Machines can be manufactured in several different ways to handle the cap and bottle combination to be used on a packaging line.  Of course, almost any capping machine can be built to run production semi-automatically or automatically.  But different machines will also be built to handle different types of caps, from screw caps to snap on caps and ROPP caps.  The operation of each type of capping machine will differ as to the method used to tighten or seal the closures.

    The spindle capper is probably the most popular automatic capping machine for screw type caps.  This capper receives bottles with caps already set in place and then automatically tightens the caps using several sets of matched spinning disks, or spindle wheels.  The capping process will run continuously without bottles stopping for indexing, cap placement or any other reason.

    The automatic Feeding Machine of PLC is designed to minimize human and human errors in the manufacturing industry. The system based on PLC is used for the automation of various industrial processes, especially in the packaging department. The bottle filling and capping machine is a programmable system that enables users to automate the bottle filling process.


    In this system, the empty bottle is placed on the conveyor belt from one end and then moved to the nozzle driven by the water pump. The switching of the pump is controlled by the playback board, which determines the amount of time that the pump must be started, so as to determine the water level in the water bottle.


    Once the bottle is full, it enters the rotating cylinder guided by the stepping motor, in which the "bottle cap installation mechanism" installs the bottle cap on the bottle. The same rotating cylinder aligns the bottle with the DC motor, in which the pneumatic piston pushes the DC motor on the cover. With the help of the rotating movement set by the DC motor, the bottle cap of the Acacia bottle is tightened. These filled and capped bottles are then transferred to the packing box through the next conveyor belt.


    All these processes are controlled by programmable logic controller (PLC), that is, these processes can be easily modified and new processes can be added according to the needs of users.

    When you have a production line handling a large volume of containers that must be sorted and organized in an efficient way, a bottle Unscrambler Machine can prove integral. Here is an overview of bottle unscrambler technology and its benefits of use.


    What Does a Bottle Unscrambler Do?


    Bottle unscramblers sort—unscramble—containers that are housed in some type of supply hopper and organize them into different groups to be used along a production line conveyor system where they are filled, decorated, and/or put into cases or pallets. They work effectively on a wide range of bottles and containers, including those used in the pharmaceutical, food and beverage, household, chemical and cosmetic industries. This includes items like dairy products, bottled water, juice, car care products, detergents, cleaners, lotions, motor oil, hair care products and many more—all of which often offer the same product but in different size bottles.

    How Can a Bottle Unscrambler Help Your Business?


    These easy-to-integrate systems are often considered to be high on efficiency and simplicity while being flexible enough to work with a number of types of containers in various sizes and shapes without having to stop the process and do a change-over. That’s a lot of benefits for a business that provides a compelling story. But, the advantages of a Plc Controlled Bottle Unscrambler Machine don’t stop here. These are often very flexible devices that can be added to filling machines, labelers, and even automatic assembly systems. This means that it can add convenience and productivity to your business without further complicating your production line or requiring large capital expenditure. You will even be able to maintain performance quality while taking on new bottles sizes, which often happens in these industries as companies decide to retool their packaging over time. That way, you can keep costs down while not losing this business to another company that can handle the new container types. Some companies have to separate containers using a manual process, but this is cumbersome and unnecessary when a machine is readily available that can unscramble hundreds of bottles per minute and accurately. This will vastly increase productivity and reduce costly errors and labor costs, including training time.]]>
    Overflow fillers, gravity fillers, piston Filling Machines and other liquid fillers all vary in the way that they move product into a bottle or container. However, the automatic versions of these machines almost always have certain features in common. These features are intended to add efficiency, consistency and reliability to the packaging equipment. Below are a few of the most common features of found on Liquid Packaging Solutions' bottle fillers.

    Heavy Duty and Portable Stainless Steel Frame

    For consistent and reliable fills, the Filling Machine must be stabile throughout the process. The heavy duty stainless steel frame protects against shifting, vibrating and other movements that might effect the volume or the level of the fill, while also avoiding splashes and spills. The stainless steel material is compatible with a vast majority of products, though there are exceptions. When corrosive liquids are run on the machinery, other construction materials may be used for the frame, including HDPE. Ultimately, the material used will be that material which will better extend the useful life of the equipment.

    Easy Adjustments From Height to Heads

    Many packagers fill more than a single product, or at the very least fill into bottles of multiple sizes and shapes. Changing over from one product or bottle to another means stopping production on the liquid filler. These machines include simple adjustments to minimize downtime and maximize production. Fill heads can typically be moved using simple fingertip adjustment knobs, while power height comes standard on automatic equipment, allowing up and down movement with the flip of a switch. Even auxillary equipment such as power conveyors include knob adjustments or other simple components for railing and other changes. Other adjustments, such as time and delay settings, can easily be made from the operator control panel, discussed in more detail below.

    PLC with Touch Screen Controls

    Along with easy adjustments to the components of the liquid filler, the Programmable Logic Controller (PLC) and operator interface allow the operators of the equipment to quickly and easily set up indexing times, fill times and other settings for the machinery. The panel allows controls to be centrally located and may also include controls for other equipment such as power conveyors, turntables and more. One of the best features of the PLC is the ability to record recipes for product and bottle combinations. Once all settings have been input for a combination, the combination can be saved and recalled at a later date, making changeover that much easier.

    Capping Machines can be manufactured in several different ways to handle the cap and bottle combination to be used on a packaging line.  Of course, almost any capping machine can be built to run production semi-automatically or automatically.  But different machines will also be built to handle different types of caps, from screw caps to snap on caps and ROPP caps.  The operation of each type of capping machine will differ as to the method used to tighten or seal the closures.

    The spindle capper is probably the most popular automatic capping machine for screw type caps.  This capper receives bottles with caps already set in place and then automatically tightens the caps using several sets of matched spinning disks, or spindle wheels.  The capping process will run continuously without bottles stopping for indexing, cap placement or any other reason.

    The automatic Feeding Machine of PLC is designed to minimize human and human errors in the manufacturing industry. The system based on PLC is used for the automation of various industrial processes, especially in the packaging department. The bottle filling and capping machine is a programmable system that enables users to automate the bottle filling process.


    In this system, the empty bottle is placed on the conveyor belt from one end and then moved to the nozzle driven by the water pump. The switching of the pump is controlled by the playback board, which determines the amount of time that the pump must be started, so as to determine the water level in the water bottle.


    Once the bottle is full, it enters the rotating cylinder guided by the stepping motor, in which the "bottle cap installation mechanism" installs the bottle cap on the bottle. The same rotating cylinder aligns the bottle with the DC motor, in which the pneumatic piston pushes the DC motor on the cover. With the help of the rotating movement set by the DC motor, the bottle cap of the Acacia bottle is tightened. These filled and capped bottles are then transferred to the packing box through the next conveyor belt.


    All these processes are controlled by programmable logic controller (PLC), that is, these processes can be easily modified and new processes can be added according to the needs of users.

    When you have a production line handling a large volume of containers that must be sorted and organized in an efficient way, a bottle Unscrambler Machine can prove integral. Here is an overview of bottle unscrambler technology and its benefits of use.


    What Does a Bottle Unscrambler Do?


    Bottle unscramblers sort—unscramble—containers that are housed in some type of supply hopper and organize them into different groups to be used along a production line conveyor system where they are filled, decorated, and/or put into cases or pallets. They work effectively on a wide range of bottles and containers, including those used in the pharmaceutical, food and beverage, household, chemical and cosmetic industries. This includes items like dairy products, bottled water, juice, car care products, detergents, cleaners, lotions, motor oil, hair care products and many more—all of which often offer the same product but in different size bottles.

    How Can a Bottle Unscrambler Help Your Business?


    These easy-to-integrate systems are often considered to be high on efficiency and simplicity while being flexible enough to work with a number of types of containers in various sizes and shapes without having to stop the process and do a change-over. That’s a lot of benefits for a business that provides a compelling story. But, the advantages of a Plc Controlled Bottle Unscrambler Machine don’t stop here. These are often very flexible devices that can be added to filling machines, labelers, and even automatic assembly systems. This means that it can add convenience and productivity to your business without further complicating your production line or requiring large capital expenditure. You will even be able to maintain performance quality while taking on new bottles sizes, which often happens in these industries as companies decide to retool their packaging over time. That way, you can keep costs down while not losing this business to another company that can handle the new container types. Some companies have to separate containers using a manual process, but this is cumbersome and unnecessary when a machine is readily available that can unscramble hundreds of bottles per minute and accurately. This will vastly increase productivity and reduce costly errors and labor costs, including training time.]]> https://uhm.vn/forum/Thread-Easy-Ways-to-Sneak-Some-Superfoods-Into-Your-Daily-Diet--354540 Fri, 22 Oct 2021 11:58:48 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-Easy-Ways-to-Sneak-Some-Superfoods-Into-Your-Daily-Diet--354540
    Garlic

    The benefits: Anti-everything: anticancer, antibacterial, antifungal, anti-inflammatory The best ways to eat it: If raw Fresh Garlic is a bit too pungent for you, roast some to bring out its sweetness. Add sea salt and olive oil to your roasted garlic, then spread on toast for some delicious Peeled Garlic jam. If your taste buds prefer a punch of flavor, chop a few fresh cloves and add them to your salad dressing; now, when your breath smells like someone let an animal die inside you, you will know that you are protecting your body from every disease ever.

    Ginger


    The benefits: Anti-inflammatory; anticarcinogen; digestive aid The best ways to eat Fresh Ginger: Forget the sugar-loaded ginger ale and gingerbread cookies. Choose the real deal. Kick up the flavor of sauces by adding some sliced ginger or blending some into your favorite marinade. Add a few knobs into your smoothie for a spicy boost that will keep your stomach feeling sane for the whole day.

    Chestnuts, low in fat and high in vitamin C, are more similar to fruits than true nuts. They have a spiny husk and a dark brown shell, both of which must be removed before eating. Chestnuts have been a food source for thousands of years. They can be eaten raw, roasted, ground into flour, or mixed into pastries. They grow on trees in the genus Castanea, and many species in this group can live for an impressive 500 years or more.


    There are four main species of chestnut trees: the Chinese chestnut, the Japanese chestnut, the European chestnut, and the American chestnut. The trees are native to many places around the world, but once had a much smaller growing area before people began to transplant them.


    The American chestnut tree was once common across the eastern United States, but it was nearly wiped out by a fungal infestation in the early 1900s. The European chestnut, Castanea sativa, is the most common and provides the majority of chestnuts sold in grocery stores today.

    Health Benefits

    Chestnuts are rich in vitamin C, which makes them unique among nuts. In fact, half a cup of raw chestnuts gives you 35 to 45 percent of your daily intake of vitamin C.

    Chestnuts lose some of their vitamin C if you boil or roast them, but still have anywhere from 15 to 20 percent of your daily intake for this healthy vitamin. To retain more vitamin C in chestnuts when cooking, you can roast them at lower temperatures or use a food dehydrator to dry them.

    Chestnuts remain a good source of antioxidants, even after cooking. They’re rich in gallic acid and ellagic acid—two antioxidants that increase in concentration when cooked.

    A pear is a mild, sweet fruit with a fibrous center. Pears are rich in essential antioxidants, plant compounds, and dietary fiber. They pack all of these nutrients in a fat-free, cholesterol-free, 100 calorie package. As part of a balanced, nutritious diet, consuming pears could support weight loss and reduce a persons risk of cancer, diabetes, and heart disease.


    In this article, we provide a nutritional breakdown of the pear and an in-depth look at its possible benefits. We also give tips on how to incorporate more pears into the diet and list some potential health risks of consuming them. Consuming all types of fruits and vegetables can reduce the risk of several health conditions. Ya Pears are no exception. They provide a significant amount of fiber and other essential nutrients, and they can help reduce the risk of heart disease, diabetes, and certain gut conditions.


    Apples are a popular fruit, containing antioxidants, vitamins, dietary fiber, and a range of other nutrients. Due to their varied nutrient content, they may help prevent several health conditions. Apples come in a variety of shapes, colors, and flavors and provide a range of nutrients that can benefit many different aspects of a person’s health. For example, they may help reduce the risk of cancer, obesity, heart disease, diabetes, and several other conditions.

    The carrot (Daucus carota) is a root vegetable often claimed to be the perfect health food. It is crunchy, tasty, and highly nutritious. Carrots are a particularly good source of beta carotene, fiber, vitamin K1, potassium, and antioxidants. They also have a number of health benefits. They’re a weight-loss-friendly food and have been linked to lower cholesterol levels and improved eye health.


    What's more, their carotene antioxidants have been linked to a reduced risk of cancer. Carrots are found in many colors, including yellow, white, orange, red, and purple. Orange carrots get their bright color from beta carotene, an antioxidant that your body converts into vitamin A.]]>
    Garlic

    The benefits: Anti-everything: anticancer, antibacterial, antifungal, anti-inflammatory The best ways to eat it: If raw Fresh Garlic is a bit too pungent for you, roast some to bring out its sweetness. Add sea salt and olive oil to your roasted garlic, then spread on toast for some delicious Peeled Garlic jam. If your taste buds prefer a punch of flavor, chop a few fresh cloves and add them to your salad dressing; now, when your breath smells like someone let an animal die inside you, you will know that you are protecting your body from every disease ever.

    Ginger


    The benefits: Anti-inflammatory; anticarcinogen; digestive aid The best ways to eat Fresh Ginger: Forget the sugar-loaded ginger ale and gingerbread cookies. Choose the real deal. Kick up the flavor of sauces by adding some sliced ginger or blending some into your favorite marinade. Add a few knobs into your smoothie for a spicy boost that will keep your stomach feeling sane for the whole day.

    Chestnuts, low in fat and high in vitamin C, are more similar to fruits than true nuts. They have a spiny husk and a dark brown shell, both of which must be removed before eating. Chestnuts have been a food source for thousands of years. They can be eaten raw, roasted, ground into flour, or mixed into pastries. They grow on trees in the genus Castanea, and many species in this group can live for an impressive 500 years or more.


    There are four main species of chestnut trees: the Chinese chestnut, the Japanese chestnut, the European chestnut, and the American chestnut. The trees are native to many places around the world, but once had a much smaller growing area before people began to transplant them.


    The American chestnut tree was once common across the eastern United States, but it was nearly wiped out by a fungal infestation in the early 1900s. The European chestnut, Castanea sativa, is the most common and provides the majority of chestnuts sold in grocery stores today.

    Health Benefits

    Chestnuts are rich in vitamin C, which makes them unique among nuts. In fact, half a cup of raw chestnuts gives you 35 to 45 percent of your daily intake of vitamin C.

    Chestnuts lose some of their vitamin C if you boil or roast them, but still have anywhere from 15 to 20 percent of your daily intake for this healthy vitamin. To retain more vitamin C in chestnuts when cooking, you can roast them at lower temperatures or use a food dehydrator to dry them.

    Chestnuts remain a good source of antioxidants, even after cooking. They’re rich in gallic acid and ellagic acid—two antioxidants that increase in concentration when cooked.

    A pear is a mild, sweet fruit with a fibrous center. Pears are rich in essential antioxidants, plant compounds, and dietary fiber. They pack all of these nutrients in a fat-free, cholesterol-free, 100 calorie package. As part of a balanced, nutritious diet, consuming pears could support weight loss and reduce a persons risk of cancer, diabetes, and heart disease.


    In this article, we provide a nutritional breakdown of the pear and an in-depth look at its possible benefits. We also give tips on how to incorporate more pears into the diet and list some potential health risks of consuming them. Consuming all types of fruits and vegetables can reduce the risk of several health conditions. Ya Pears are no exception. They provide a significant amount of fiber and other essential nutrients, and they can help reduce the risk of heart disease, diabetes, and certain gut conditions.


    Apples are a popular fruit, containing antioxidants, vitamins, dietary fiber, and a range of other nutrients. Due to their varied nutrient content, they may help prevent several health conditions. Apples come in a variety of shapes, colors, and flavors and provide a range of nutrients that can benefit many different aspects of a person’s health. For example, they may help reduce the risk of cancer, obesity, heart disease, diabetes, and several other conditions.

    The carrot (Daucus carota) is a root vegetable often claimed to be the perfect health food. It is crunchy, tasty, and highly nutritious. Carrots are a particularly good source of beta carotene, fiber, vitamin K1, potassium, and antioxidants. They also have a number of health benefits. They’re a weight-loss-friendly food and have been linked to lower cholesterol levels and improved eye health.


    What's more, their carotene antioxidants have been linked to a reduced risk of cancer. Carrots are found in many colors, including yellow, white, orange, red, and purple. Orange carrots get their bright color from beta carotene, an antioxidant that your body converts into vitamin A.]]> https://uhm.vn/forum/Thread-How-Does-a-Fuel-Level-Sensor-Work--354537 Fri, 22 Oct 2021 11:56:45 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-How-Does-a-Fuel-Level-Sensor-Work--354537
    Sensors are a crucial part of most vehicles, especially when determining the fuel level in automobiles and aircraft. Whilst running out of fuel might be inconvenient and costly when driving an automobile, in an aircraft it could have dire consequences. In this article, we look at how these fuel level sensors work. Fuel Level Sensors, also known as fuel gauges, allow drivers to monitor fuel consumption and help them to determine when to refill the tank. They consist of two main components: the sensing system itself (also known as the sender) and the indicator (also commonly referred to as the gauge).

    Capacitive Fuel Level Sensors work by measuring the voltage across a variable resistor within the sensing system, to determine the level of fuel; which is then relayed to the driver via the indicating system. Several components work within the sensing system, enabling it to detect how much fuel is in a tank, including the float switch, a variable resistor, and a wiper. The sensor system is relatively simple compared to other sensors currently produced, although newer sensor systems can also utilize microprocessors for faster and more accurate measurements.

    Global Positioning System (GPS) is a worldwide radio-navigation system formed from the constellation of 24 satellites and their ground stations. The Global Positioning System is mainly funded and controlled by the U.S Department of Defense (DOD). The system was initially designed for the operation of the U.S. military. But today, there are also many civil users of GPS across the whole world. Civil users are allowed to use the Standard Positioning Service without any kind of charge or restrictions.


    Global Positioning System tracking is a method of working out exactly where something is. A GPS tracking system, for example, may be placed in a vehicle, on a cell phone, or on special GPS devices, which can either be a fixed or portable unit. GPS Tracker works by providing information on the exact location. It can also track the movement of a vehicle or person. So, for example, a GPS Tracking Software can be used by a company to monitor the route and progress of a delivery truck, and by parents to check on the location of their child, or even to monitor high-valued assets in transit.


    A GPS tracking system uses the Global Navigation Satellite System (GNSS) network. This network incorporates a range of satellites that use microwave signals that are transmitted to GPS Vehicle Tracker devices to give information on location, vehicle speed, time, and direction. So, a GPS tracking system can potentially give both real-time and historic navigation data on any kind of journey.

    Driver monitoring systems (DMS) are making a pivotal contribution to road safety, both in commercial truck fleets and passenger cars. These systems use a driver-facing camera to evaluate the driver’s state of alertness. If it detects fatigue or distraction, Driver Fatigue Monitor sends a warning or alert. In partially automated vehicles, the system notifies the driver when a vehicle-initiated handover is required.


    It is now well accepted that camera-based DMS is the most appropriate way to directly track driver drowsiness and distraction and perform safe, vehicle-initiated handover in semi-autonomous cars, concluded ABI Research analysts in a recent study of driver and in-cabin monitoring systems.


    The DMS segment is poised for significant growth thanks in part to the support of leading safety agencies. In February 2020, the National Transportation Safety Board (NTSB) in the US recommended the use of DMS as an effective means of driver engagement in SAE Level 2 vehicles. Euro NCAP recognized the importance of DMS in its revised crash-test safety standards, which starting this year require DMS for a five-star rating. By 2022, DMS will become mandatory across the European Union for M1, M2, M3, N1, N2, and N3 new vehicle categories.


    Fleet Management Sensor has been radically transformed by innovations such as smart devices and sensors in the digital age. The IoT-enabled future of the supply chain industry looks promising as more companies across the globe are embracing the technology.


    Research predicts the revenue of the global IoT fleet management market will reach an estimated US$15,500 million by 2024. This is not surprising at all because the sector has achieved great strides by being tech-forward.


    The acronym stands for Mobile Digital Video Recorder and is responsible for all business intelligence behind the video monitoring, such as storing videos, settings, remote functions, etc. Without it, cameras are simply cameras. The MDVR is capable of recording your images in high resolution, storing the files internally and sending them to the cloud, when connected via Wi-Fi, 4G and Ethernet (the conventional internet cable). However, in the event of an accident, the MDVR can be used to retrieve the information, which is stored on SSD for approximately 10 days.]]>
    Sensors are a crucial part of most vehicles, especially when determining the fuel level in automobiles and aircraft. Whilst running out of fuel might be inconvenient and costly when driving an automobile, in an aircraft it could have dire consequences. In this article, we look at how these fuel level sensors work. Fuel Level Sensors, also known as fuel gauges, allow drivers to monitor fuel consumption and help them to determine when to refill the tank. They consist of two main components: the sensing system itself (also known as the sender) and the indicator (also commonly referred to as the gauge).

    Capacitive Fuel Level Sensors work by measuring the voltage across a variable resistor within the sensing system, to determine the level of fuel; which is then relayed to the driver via the indicating system. Several components work within the sensing system, enabling it to detect how much fuel is in a tank, including the float switch, a variable resistor, and a wiper. The sensor system is relatively simple compared to other sensors currently produced, although newer sensor systems can also utilize microprocessors for faster and more accurate measurements.

    Global Positioning System (GPS) is a worldwide radio-navigation system formed from the constellation of 24 satellites and their ground stations. The Global Positioning System is mainly funded and controlled by the U.S Department of Defense (DOD). The system was initially designed for the operation of the U.S. military. But today, there are also many civil users of GPS across the whole world. Civil users are allowed to use the Standard Positioning Service without any kind of charge or restrictions.


    Global Positioning System tracking is a method of working out exactly where something is. A GPS tracking system, for example, may be placed in a vehicle, on a cell phone, or on special GPS devices, which can either be a fixed or portable unit. GPS Tracker works by providing information on the exact location. It can also track the movement of a vehicle or person. So, for example, a GPS Tracking Software can be used by a company to monitor the route and progress of a delivery truck, and by parents to check on the location of their child, or even to monitor high-valued assets in transit.


    A GPS tracking system uses the Global Navigation Satellite System (GNSS) network. This network incorporates a range of satellites that use microwave signals that are transmitted to GPS Vehicle Tracker devices to give information on location, vehicle speed, time, and direction. So, a GPS tracking system can potentially give both real-time and historic navigation data on any kind of journey.

    Driver monitoring systems (DMS) are making a pivotal contribution to road safety, both in commercial truck fleets and passenger cars. These systems use a driver-facing camera to evaluate the driver’s state of alertness. If it detects fatigue or distraction, Driver Fatigue Monitor sends a warning or alert. In partially automated vehicles, the system notifies the driver when a vehicle-initiated handover is required.


    It is now well accepted that camera-based DMS is the most appropriate way to directly track driver drowsiness and distraction and perform safe, vehicle-initiated handover in semi-autonomous cars, concluded ABI Research analysts in a recent study of driver and in-cabin monitoring systems.


    The DMS segment is poised for significant growth thanks in part to the support of leading safety agencies. In February 2020, the National Transportation Safety Board (NTSB) in the US recommended the use of DMS as an effective means of driver engagement in SAE Level 2 vehicles. Euro NCAP recognized the importance of DMS in its revised crash-test safety standards, which starting this year require DMS for a five-star rating. By 2022, DMS will become mandatory across the European Union for M1, M2, M3, N1, N2, and N3 new vehicle categories.


    Fleet Management Sensor has been radically transformed by innovations such as smart devices and sensors in the digital age. The IoT-enabled future of the supply chain industry looks promising as more companies across the globe are embracing the technology.


    Research predicts the revenue of the global IoT fleet management market will reach an estimated US$15,500 million by 2024. This is not surprising at all because the sector has achieved great strides by being tech-forward.


    The acronym stands for Mobile Digital Video Recorder and is responsible for all business intelligence behind the video monitoring, such as storing videos, settings, remote functions, etc. Without it, cameras are simply cameras. The MDVR is capable of recording your images in high resolution, storing the files internally and sending them to the cloud, when connected via Wi-Fi, 4G and Ethernet (the conventional internet cable). However, in the event of an accident, the MDVR can be used to retrieve the information, which is stored on SSD for approximately 10 days.]]> https://uhm.vn/forum/Thread-Acrylic-Plastic--354531 Fri, 22 Oct 2021 11:53:38 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-Acrylic-Plastic--354531
    Acrylic plastic refers to a family of synthetic, or man-made, plastic materials containing one or more derivatives of acrylic acid. The most common acrylic plastic is polymethyl methacrylate (PMMA), which is sold under the brand names of Plexiglas, Lucite, Perspex, and Crystallite. PMMA is a tough, highly transparent material with excellent resistance to ultraviolet radiation and weathering. It can be colored, molded, cut, drilled, and formed. These properties make it ideal for many applications including airplane windshields, skylights, automobile taillights, and outdoor signs. One notable application is the ceiling of the Houston Astrodome which is composed of hundreds of double-insulating panels of PMMA acrylic plastic.

    Like all plastics, Acrylic Rod plastics are polymers. The word polymer comes from the Greek words poly, meaning many, and meros, meaning apart. A polymer, therefore, is a material made up of many molecules, or parts, linked together like a chain. Polymers may have hundreds, or even thousands, of molecules linked together. More importantly, a polymer is a material that has properties entirely different than its component parts. The process of making a polymer, known as polymerization, has been likened to shoveling scrap glass, copper, and other materials into a box, shaking the box, and coming back in an hour to find a working color television set. The glass, copper, and other component parts are still there, but they have been reassembled into something that looks and functions entirely differently.

    The first plastic polymer, celluloid, a combination of cellulose nitrate and camphor, was developed in 1869. It was based on the natural polymer cellulose, which is present in plants. Celluloid was used to make many items including photographic film, combs, and men's shirt collars.

    In 1909, Leo Baekeland developed the first commercially successful synthetic plastic polymer when he patented phenol-formaldehyde resin, which he named Bakelite. Bakelite was an immediate success. It could be machined and molded. It was an excellent electrical insulator and was resistant to heat, acids, and weather. It could also be colored and dyed for use in decorative objects. Bakelite plastic was used in radio, telephone, and electrical equipment, as well as countertops, buttons, and knife handles.

    Acrylic acid was first prepared in 1843. Methacrylic acid, which is a derivative of acrylic acid, was formulated in 1865. When methacrylic acid is reacted with methyl alcohol, it results in an ester known as methyl methacrylate. The polymerization process to turn methyl methacrylate into polymethyl methacrylate was discovered by the German chemists Fitting and Paul in 1877, but it wasn't until 1936 that the process was used to produce sheets of Clear Acrylic Rod safety glass commercially. During World War II, acrylic glass was used for periscope ports on submarines and for windshields, canopies, and gun turrets on airplanes.

    Acrylic Line Rod plastic polymers are formed by reacting a monomer, such as methyl methacrylate, with a catalyst. A typical catalyst would be an organic peroxide. The catalyst starts the reaction and enters into it to keep it going, but does not become part of the resulting polymer.

    Acrylic plastics are available in three forms: flat sheets, elongated shapes (rods and tubes), and molding powder. Molding powders are sometimes made by a process known as suspension polymerization in which the reaction takes place between tiny droplets of the monomer suspended in a solution of water and catalyst. This results in grains of polymer with tightly controlled molecular weight suitable for molding or extrusion.

    Acrylic plastic sheets are formed by a process known as bulk polymerization. In this process, the monomer and catalyst are poured into a mold where the reaction takes place. Two methods of bulk polymerization may be used: batch cell or continuous. The batch cell is the most common because it is simple and is easily adapted for making Acrylic Tubes in thicknesses from 0.06 to 6.0 inches (0.16-15 cm) and widths from 3 feet (0.9 m) up to several hundred feet. The batch cell method may also be used to form rods and Acrylic Diffuser Tubes. The continuous method is quicker and involves less labor. It is used to make sheets of thinner thicknesses and smaller widths than those produced by the batch cell method.

    The storage, handling, and processing of the chemicals that make Opal Acrylic Tubes are done under controlled environmental conditions to prevent contamination of the material or unsafe chemical reactions. The control of temperature is especially critical to the polymerization process. Even the initial temperatures of the monomer and catalyst are controlled before they are introduced into the mold. During the entire process, the temperature of the reacting material is monitored and controlled to ensure the heating and cooling cycles are the proper temperature and duration. Samples of finished acrylic materials are also given periodic laboratory analysis to confirm physical, optical, and chemical properties.

    PC Tubes are the clearest extruded tubes on the market today delivering brilliant quality, superior performance, and durability. Polycarbonate tubes are characterized by their flawless optics, and a perfectly smooth surface free of striations.

    Clear PC Tubes are optically pure. Our transparent Polycarbonate tubes are often used in the stand- and exhibition building, in the furniture/interior design branches, and mostly for technical applications such as reactors. Polycarbonate tubes are reasonable UV stable and weatherproof but are not designed for long-term outdoor applications. They will yellow if they are outside for a long period.

    High-quality, design-orientated applications within the architectural lighting industry can be easily created with our Polycarbonate tubes. You can create impressive lighting effects using our PC Color Tubes which are an innovative solution that fits particularly well for Lighting and architectural applications. White or frosted satin surface finishes provide excellent diffused light creating a velvety nonglare surface.

    Polycarbonate tubes can be cut, sanded, drilled, etc. with the appropriate tools. They require high cutting speeds and effective cooling as their low heat conduction can easily lead to overheating and local thermal stress.

    Excess friction, especially with Polycarbonate tubes can cause melting which leads to a tacky surface and difficulty machining. Drilling should never be performed without using some water-based cooling lubricant (i.e. an emulsion). For eliminating internal stress annealing may be necessary.]]>
    Acrylic plastic refers to a family of synthetic, or man-made, plastic materials containing one or more derivatives of acrylic acid. The most common acrylic plastic is polymethyl methacrylate (PMMA), which is sold under the brand names of Plexiglas, Lucite, Perspex, and Crystallite. PMMA is a tough, highly transparent material with excellent resistance to ultraviolet radiation and weathering. It can be colored, molded, cut, drilled, and formed. These properties make it ideal for many applications including airplane windshields, skylights, automobile taillights, and outdoor signs. One notable application is the ceiling of the Houston Astrodome which is composed of hundreds of double-insulating panels of PMMA acrylic plastic.

    Like all plastics, Acrylic Rod plastics are polymers. The word polymer comes from the Greek words poly, meaning many, and meros, meaning apart. A polymer, therefore, is a material made up of many molecules, or parts, linked together like a chain. Polymers may have hundreds, or even thousands, of molecules linked together. More importantly, a polymer is a material that has properties entirely different than its component parts. The process of making a polymer, known as polymerization, has been likened to shoveling scrap glass, copper, and other materials into a box, shaking the box, and coming back in an hour to find a working color television set. The glass, copper, and other component parts are still there, but they have been reassembled into something that looks and functions entirely differently.

    The first plastic polymer, celluloid, a combination of cellulose nitrate and camphor, was developed in 1869. It was based on the natural polymer cellulose, which is present in plants. Celluloid was used to make many items including photographic film, combs, and men's shirt collars.

    In 1909, Leo Baekeland developed the first commercially successful synthetic plastic polymer when he patented phenol-formaldehyde resin, which he named Bakelite. Bakelite was an immediate success. It could be machined and molded. It was an excellent electrical insulator and was resistant to heat, acids, and weather. It could also be colored and dyed for use in decorative objects. Bakelite plastic was used in radio, telephone, and electrical equipment, as well as countertops, buttons, and knife handles.

    Acrylic acid was first prepared in 1843. Methacrylic acid, which is a derivative of acrylic acid, was formulated in 1865. When methacrylic acid is reacted with methyl alcohol, it results in an ester known as methyl methacrylate. The polymerization process to turn methyl methacrylate into polymethyl methacrylate was discovered by the German chemists Fitting and Paul in 1877, but it wasn't until 1936 that the process was used to produce sheets of Clear Acrylic Rod safety glass commercially. During World War II, acrylic glass was used for periscope ports on submarines and for windshields, canopies, and gun turrets on airplanes.

    Acrylic Line Rod plastic polymers are formed by reacting a monomer, such as methyl methacrylate, with a catalyst. A typical catalyst would be an organic peroxide. The catalyst starts the reaction and enters into it to keep it going, but does not become part of the resulting polymer.

    Acrylic plastics are available in three forms: flat sheets, elongated shapes (rods and tubes), and molding powder. Molding powders are sometimes made by a process known as suspension polymerization in which the reaction takes place between tiny droplets of the monomer suspended in a solution of water and catalyst. This results in grains of polymer with tightly controlled molecular weight suitable for molding or extrusion.

    Acrylic plastic sheets are formed by a process known as bulk polymerization. In this process, the monomer and catalyst are poured into a mold where the reaction takes place. Two methods of bulk polymerization may be used: batch cell or continuous. The batch cell is the most common because it is simple and is easily adapted for making Acrylic Tubes in thicknesses from 0.06 to 6.0 inches (0.16-15 cm) and widths from 3 feet (0.9 m) up to several hundred feet. The batch cell method may also be used to form rods and Acrylic Diffuser Tubes. The continuous method is quicker and involves less labor. It is used to make sheets of thinner thicknesses and smaller widths than those produced by the batch cell method.

    The storage, handling, and processing of the chemicals that make Opal Acrylic Tubes are done under controlled environmental conditions to prevent contamination of the material or unsafe chemical reactions. The control of temperature is especially critical to the polymerization process. Even the initial temperatures of the monomer and catalyst are controlled before they are introduced into the mold. During the entire process, the temperature of the reacting material is monitored and controlled to ensure the heating and cooling cycles are the proper temperature and duration. Samples of finished acrylic materials are also given periodic laboratory analysis to confirm physical, optical, and chemical properties.

    PC Tubes are the clearest extruded tubes on the market today delivering brilliant quality, superior performance, and durability. Polycarbonate tubes are characterized by their flawless optics, and a perfectly smooth surface free of striations.

    Clear PC Tubes are optically pure. Our transparent Polycarbonate tubes are often used in the stand- and exhibition building, in the furniture/interior design branches, and mostly for technical applications such as reactors. Polycarbonate tubes are reasonable UV stable and weatherproof but are not designed for long-term outdoor applications. They will yellow if they are outside for a long period.

    High-quality, design-orientated applications within the architectural lighting industry can be easily created with our Polycarbonate tubes. You can create impressive lighting effects using our PC Color Tubes which are an innovative solution that fits particularly well for Lighting and architectural applications. White or frosted satin surface finishes provide excellent diffused light creating a velvety nonglare surface.

    Polycarbonate tubes can be cut, sanded, drilled, etc. with the appropriate tools. They require high cutting speeds and effective cooling as their low heat conduction can easily lead to overheating and local thermal stress.

    Excess friction, especially with Polycarbonate tubes can cause melting which leads to a tacky surface and difficulty machining. Drilling should never be performed without using some water-based cooling lubricant (i.e. an emulsion). For eliminating internal stress annealing may be necessary.]]> https://uhm.vn/forum/Thread-What-does-the-fire-retardant-wadding-protect--354524 Fri, 22 Oct 2021 11:49:18 +0700 pd22ing22]]> https://uhm.vn/forum/Thread-What-does-the-fire-retardant-wadding-protect--354524
    The purpose of Fireproof Flame Retardant Wadding is to protect the parachute from the heat of the ejection charge. This is a type of cloth wadding that does not need to be replaced between flights. It saves money, especially on large diameter rockets that would need a lot of regular disposable wadding to protect the chute.


    Simply so, what can I use for rocket wadding? By far the most commonly used alternative to recovery wadding is cellulose insulation. Cellulose is made from recycled paper and is treated with boric acid to be fire-resistant. Boric acid is a natural substance, but it is also poisonous.


    Also Know, what does recovery wadding do? Recovery wadding is necessary to protect your parachute from being damaged. As your rocket's motor burns out, it emits a small burst or charge that pops the nose cone out, and deploys the parachute. Without the wadding, the chute could be burned.

    Products that are handcrafted offer higher quality and more attention to detail apart from taking less energy than a mass production assembly line. This makes them more environmentally sustainable. Also, when you buy a handmade product, the local artisans or the locally-owned independent businesses creating them yield a higher percentage of their revenue to their communities than chains. Because Natural Health Materials are what they are – natural, they are not made in factories. The option of customizing your purchase by dealing directly with the artisans when you purchase natural products makes your choices open to tweaking certain aspects of the product precisely to fit your needs.

    There are two sides of the acoustical coin, if you will. There are products that absorb echo within a room, and there are products that will block or stop/reduce sound transmission. There are some panels that will do a bit of both. These are generally called composites, but for now, let’s keep it simple. Sound-Absorbing And Energy-Saving Materials are used to improve the sound quality inside of the room in which they are installed. They are usually installed on the walls or ceiling as a finished surface in the room. Products that are used to block sound are used INSIDE of the wall or ceiling – as part of the construction material. They can be dense, heavy materials or materials that will decouple the wall assembly – and due to their density, often reflect the sound back into the room rather than the sound penetrating through to the other side. Absorbing the echo in a room and blocking or reducing sound are done in two very different ways and with different products and approaches.

    In fact, some people soundproofing a room on the cheap side even hang moving blankets on the wall to create a DIY Sound Absorbing Padding. If you are interested in a more professional or finished look as well as performance, there are fantastic sound-absorbing products on the market.

    In order to keep the neighbors from complaining, you are going to have to build a room within a room and float the whole thing on a layer or two of rubber so that this new room is not touching the floor. The tricky part becomes getting fresh air into the space. I would suggest using a 2×6 stud for the walls with a layer or two of 5/8” sheetrock (drywall) on the outside, some kind of Thermal Insulation on the inside and then two more layers of 5/8” sheetrock. Install a heavy, solid core door and be sure to use sealant to seal the rough opening to the studs. You are going to need to build some kind of lined duct or chamber to pull or push fresh air into the room as well as to return it to the rest of the air in the apartment. If this isn’t done correctly, it can quickly negate the walls ability to block sound.

    Filter And Filter Materials are usually made of spun fiberglass material or from pleated paper or cloth enclosed in a cardboard frame. Its basic function is to clean the air that circulates through your heating and cooling system. Filters trap and hold many types of particulates and contaminants that could affect your health and comfort, including:

            Dust and dirt

            Pollen

            Mold and mold spores

            Fibers and lint
 
            Metal, plaster or wood particles

            Hair and animal fur

    Filtration usually occurs when expended air is brought back into the HVAC equipment to be conditioned and distributed again. The air is forced through the filter, and the material removes particulates and other contaminants from the air.

    Meltblown polypropylene is used as the middle layer of many certified medical masks and in the manufacture of respirators such as N95s: it filters very well. It remains in short supply, with many distributors in Canada fully committed to July 2021. It is not intended to be washed, though novel programs for limited reuse of respirators have been developed for hospitals.


    Because of the supply issue and because it is not washable, we do not recommend using melt-blown polypropylene for reusable non-medical masks.


    Disposable non-medical Filter Fabric For Facemask intended to be inserted into pocket masks are sold commercially and may contain melt blown, spun bond and other components; it is not always possible to determine their composition from the packaging or advertisements. Currently, no standards define their use in Canada. They are designed to be discarded after each use.


    Spunlace polypropylene tends to be naturally springy and in contrast to spunbond and meltblown, it absorbs liquids. Some wet wipes are produced by spunlace methods. However, the material used is often not polypropylene but rather viscose-polyester blend, to increase absorbency. The composition of the wet ingredients is clearly specified on packaging, but many wipes do not include the fibre composition of the material. These materials are not intended to be laundered and reused. Some wipes contain active ingredients that might be harmful if inhaled. For all these reasons, we do not recommend using dried-out wipes as Eco-Friendly Materials filters.]]>
    The purpose of Fireproof Flame Retardant Wadding is to protect the parachute from the heat of the ejection charge. This is a type of cloth wadding that does not need to be replaced between flights. It saves money, especially on large diameter rockets that would need a lot of regular disposable wadding to protect the chute.


    Simply so, what can I use for rocket wadding? By far the most commonly used alternative to recovery wadding is cellulose insulation. Cellulose is made from recycled paper and is treated with boric acid to be fire-resistant. Boric acid is a natural substance, but it is also poisonous.


    Also Know, what does recovery wadding do? Recovery wadding is necessary to protect your parachute from being damaged. As your rocket's motor burns out, it emits a small burst or charge that pops the nose cone out, and deploys the parachute. Without the wadding, the chute could be burned.

    Products that are handcrafted offer higher quality and more attention to detail apart from taking less energy than a mass production assembly line. This makes them more environmentally sustainable. Also, when you buy a handmade product, the local artisans or the locally-owned independent businesses creating them yield a higher percentage of their revenue to their communities than chains. Because Natural Health Materials are what they are – natural, they are not made in factories. The option of customizing your purchase by dealing directly with the artisans when you purchase natural products makes your choices open to tweaking certain aspects of the product precisely to fit your needs.

    There are two sides of the acoustical coin, if you will. There are products that absorb echo within a room, and there are products that will block or stop/reduce sound transmission. There are some panels that will do a bit of both. These are generally called composites, but for now, let’s keep it simple. Sound-Absorbing And Energy-Saving Materials are used to improve the sound quality inside of the room in which they are installed. They are usually installed on the walls or ceiling as a finished surface in the room. Products that are used to block sound are used INSIDE of the wall or ceiling – as part of the construction material. They can be dense, heavy materials or materials that will decouple the wall assembly – and due to their density, often reflect the sound back into the room rather than the sound penetrating through to the other side. Absorbing the echo in a room and blocking or reducing sound are done in two very different ways and with different products and approaches.

    In fact, some people soundproofing a room on the cheap side even hang moving blankets on the wall to create a DIY Sound Absorbing Padding. If you are interested in a more professional or finished look as well as performance, there are fantastic sound-absorbing products on the market.

    In order to keep the neighbors from complaining, you are going to have to build a room within a room and float the whole thing on a layer or two of rubber so that this new room is not touching the floor. The tricky part becomes getting fresh air into the space. I would suggest using a 2×6 stud for the walls with a layer or two of 5/8” sheetrock (drywall) on the outside, some kind of Thermal Insulation on the inside and then two more layers of 5/8” sheetrock. Install a heavy, solid core door and be sure to use sealant to seal the rough opening to the studs. You are going to need to build some kind of lined duct or chamber to pull or push fresh air into the room as well as to return it to the rest of the air in the apartment. If this isn’t done correctly, it can quickly negate the walls ability to block sound.

    Filter And Filter Materials are usually made of spun fiberglass material or from pleated paper or cloth enclosed in a cardboard frame. Its basic function is to clean the air that circulates through your heating and cooling system. Filters trap and hold many types of particulates and contaminants that could affect your health and comfort, including:

            Dust and dirt

            Pollen

            Mold and mold spores

            Fibers and lint
 
            Metal, plaster or wood particles

            Hair and animal fur

    Filtration usually occurs when expended air is brought back into the HVAC equipment to be conditioned and distributed again. The air is forced through the filter, and the material removes particulates and other contaminants from the air.

    Meltblown polypropylene is used as the middle layer of many certified medical masks and in the manufacture of respirators such as N95s: it filters very well. It remains in short supply, with many distributors in Canada fully committed to July 2021. It is not intended to be washed, though novel programs for limited reuse of respirators have been developed for hospitals.


    Because of the supply issue and because it is not washable, we do not recommend using melt-blown polypropylene for reusable non-medical masks.


    Disposable non-medical Filter Fabric For Facemask intended to be inserted into pocket masks are sold commercially and may contain melt blown, spun bond and other components; it is not always possible to determine their composition from the packaging or advertisements. Currently, no standards define their use in Canada. They are designed to be discarded after each use.


    Spunlace polypropylene tends to be naturally springy and in contrast to spunbond and meltblown, it absorbs liquids. Some wet wipes are produced by spunlace methods. However, the material used is often not polypropylene but rather viscose-polyester blend, to increase absorbency. The composition of the wet ingredients is clearly specified on packaging, but many wipes do not include the fibre composition of the material. These materials are not intended to be laundered and reused. Some wipes contain active ingredients that might be harmful if inhaled. For all these reasons, we do not recommend using dried-out wipes as Eco-Friendly Materials filters.]]> https://uhm.vn/forum/Thread-Medical-gloves-in-the-era-of-coronavirus-disease-2019-pandemic--340307 Thu, 23 Sep 2021 13:13:59 +0700 dnf56sdd8]]> https://uhm.vn/forum/Thread-Medical-gloves-in-the-era-of-coronavirus-disease-2019-pandemic--340307 Medical gloves in the era of coronavirus disease 2019 pandemic
The current coronavirus 2019 disease (COVID-19) pandemic has greatly changed our perspective of the risk for infection from contact, and the use of personal protective devices (PPDs) usually reserved for health care workers (HCWs) has spread to the general population, sometimes indiscriminately. As a result, medical glove stock has been depleted, but most of all medical gloves have become a source of medical concern.[1], [2], [3], [4]

The World Health Organization (WHO) has warned about the limited protective efficacy of gloves. There is high risk for infection spread with their incorrect use that could instead favor the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Regular use of gloves for daily activities may lead to a false sense of protection and to an increased risk for self-contamination. This would involve the involuntary touching of the face or the spreading of fomites to desks, phones, and computers keyboards. A study has found that viruses can survive on gloves for 2 to 4 hours.5
Hand-to-face contact has a substantial role in upper respiratory tract infections,6 , 7 although COVID-19’s main way of transmission remains symptomatic person-to-person through respiratory droplets.[1], [2], [3], [4] The Centers for Disease Control and Prevention (CDC) and the European Center for Disease Prevention and Control (ECDC) have recently provided guidance to regulate the use of gloves both in the health care setting and in the community.2 , 4 In the context of the COVID-19 pandemic (Table 1 ), gloves are recommended when caring for confirmed or suspected COVID-19 patients, especially when there is the risk of contact with body fluids (eg, blood, wound care, aerosol-generating procedures).

Hand protection with gloves is essential in any medical procedure, because skin cleaning/disinfection alone does not remove all pathogens, especially when the contamination is considerably high. Nonsterile disposable gloves should be prioritized, and ECDC alerts that no direct evidence documents an increased protection against COVID-19 through glove use, compared with proper hand hygiene alone. Meticulous hand hygiene with water and soap or by alcohol-based hand rub solutions is not avoided by the use of gloves.

There are many different types of gloves, depending on the level of protection, tactility, risk of allergy, or cost (Table 2 ). Although biohazard risk requires frequent glove changing, the extended use of gloves, decontamination with hand disinfectants, and reuse are frequent.8 All of this should be avoided, because effects of hand sanitizers are tested on the skin, whereas application on gloved hands affects gloves’ mechanical properties. In a recent investigation,9 the application of 70% ethanol or 63% isopropanol commercial disinfectants reduced the tensile strength of latex and nitrile gloves, with a higher impact on nitrile gloves. Elongation did not change much with latex gloves, but nitrile gloves were affected. There are additional concerns about permeability, as alcohol can permeate any type of glove after 10 minutes. Some types of disposable gloves are permeated at 2 minutes, and repeated exposure to disinfectants can increase the permeability of the gloves. Alcohol is inactivated in the presence of organic matter, which can easily remain on used gloves, thus potentially driving the viral transmission.

Extended length gloves are not necessary when providing care to suspected or confirmed COVID-19 patients. They are not specifically recommended, except for activities with increased risk, such as submerging hands into a solution. For standard procedures, it is sufficient to cover the cuff (wrist) of the gown while donning.[1], [2], [3], [4]

Another common measure that is no longer recommended is “double gloving,” except for surgical procedures that carry a high risk of disrupting the integrity of the glove. Double gloving seems to increase the incidence of dermatologic side effects, from irritation and overhydration to induction of latex allergy. The increase of skin damage as the consequence of overzealous PPD use and hand hygiene is an emergent consequence of the COVID-19 handling.[10], [11], [12]

About 74.5% of front-line COVID-19 HCWs developed hand dermatitis in the Chinese experience.13 A questionnaire-based study suggested that 88.5% of skin reactions on the hands are associated with the use of latex gloves.14 Three types of adverse events might occur: latex allergy, talcum powder reactions, and irritant dermatitis. Excluding latex allergy and powder within the gloves, the problem of excessive dryness and pruritus, associated with irritant dermatitis, may be aggravated by occlusion, leading to sweating and/or overhydration. This then may increase the permeability to sanitizers or detergents, creating a vicious cycle, plus aggravation of hand dermatitis.12

A peculiar pattern of hand dermatitis has been recognized, characterized by erythema and fine scaling on the palms and web spaces.15 This may be attributed to the depletion of surface lipids, resulting in deeper penetration of detergents, and progressive damage of skin layers is a major pathogenetic mechanism. Irritant contact dermatitis is more commonly found with iodophors, chlorhexidine, chloroxylenol, triclosan, and alcohol-based products, whereas allergic contact dermatitis develops due to quaternary ammonium compounds, iodine or iodophors, chlorhexidine, triclosan, chloroxylenol, and alcohol sensitization.

To date, there have been no verified reports of COVID-19 infection as direct consequence of skin damage. Angiotensin-converting enzyme 2 (ACE2), which is the main cell receptor for SARS-CoV-2 entry, can be expressed in the basal layer of the epidermis, hair follicles, and eccrine glands, as well as on skin blood vessels.16

Basic skincare measures should be taken to avoid the risk of SARS-CoV-2 entry through the skin.[10], [11], [12], [13], [14], [15] Careful hand skin drying and hypoallergenic hand cream/emollients may be employed to prevent trapping sanitizers in the web spaces. Emollients may also be applied at other times to correct any residual dryness and scaling, or with the occurrence of hand dermatitis, topical corticosteroids are indicated.

A final consideration is the generation of massive amount of medical waste, caused in part by the extensive use of PPDs.17 HCWs, together with the general population, are using more gloves than ever before, whereas it should be limited to very essential preventive measures.


Medical gloves remain an essential part of the infection-control strategy; however, caring for patients with COVID-19 has pointed out the need for more accuracy and respect of novel guidance. Prolonged use of gloves, outside of direct patient contact, might be self-defeating rather than protective. Hand dermatitis is an emerging concern. At this time, the U.S. Food and Drug Administration has not cleared, approved, or authorized any medical gloves for specific protection against the virus that causes COVID-19 or prevention of COVID-19 infection.

Broadly speaking, there are 2 types of medical gloves: examination gloves, which are ambidextrous, usually nonsterile, and come in a small range of sizes, are used for nonsterile and less dextrous tasks and also for most dental work; surgical gloves are sterile, come individually packaged in handed pairs, and are usually available in half-inch intervals of hand girth. They are used in the operating theater for a variety of dextrous tasks, ranging from microsurgery on the eye or ear to bone setting or hip replacement.
Because the majority of clinical work is not perceived to be as dextrous as surgery, less emphasis is placed on the performance of examination gloves. Until recently, both examination and surgical gloves were generally made from natural rubber latex (commonly referred to as “latex”), although alternatives were available for known cases of latex allergy. However, the lack of regulation of manufacturing processes in the early years of mass production meant that gloves often contained a high level of allergenic proteins, which led to a steady increase in the number of cases of latex allergy reported.1

Current guidelines from the National Health Service and the Royal College of Physicians2 in the United Kingdom state that “the evidence does not … support a need to ban latex completely from the workplace.” They note that nonlatex surgical gloves “have higher failure rates in use and lower user satisfaction than latex gloves.” Instead, they advocate the use of nonpowdered, low-protein latex gloves, except for employees with latex allergy, latex sensitization, or latex-induced asthma, where nonlatex alternatives are recommended. However, most primary care health care groups and hospitals in the United Kingdom have replaced latex in nonsurgical situations with less flexible alternatives3 such as nitrile to remove the risk of latex allergy in patients and practitioners.
Similarly, the American College of Allergy, Asthma, and Immunology4 recommends that “a facility-wide review of glove usage should be undertaken to determine the appropriateness of use … and thereby prevent the unnecessary use of latex gloves” and advocates nonpowdered, low-protein gloves as standard in a health care facility but also states that “hospitals need to evaluate manufacturer information on nonlatex gloves in areas of durability, barrier protection, and cost” because “latex is still considered superior with respect to barrier characteristics against transmissible diseases.” Surgeons have generally resisted moves to replace surgical gloves in the same way because of the perceived reduction in manual performance when using nonlatex alternatives.

With respect to the glove design process, there is little or no evidence that gloves are evaluated in terms of their effects on users’ manual performance. All the currently available standards5,  6 focus on the barrier integrity of the gloves by defining tensile strength, freedom from holes, and tear resistance. Similarly, much of the research on medical gloves has concerned barrier integrity7,  8 and adherence of practitioners to handwashing and glove handling guidelines.9,  10 Clearly, because the primary role of the gloves is to prevent the spread of infection, it is important that the design brief takes these things into consideration, but achieving good barrier integrity is not necessarily incompatible with achieving the best performance.

Glove performance also has an effect on safety, particularly in a surgical environment. Surgeons using plastic gloves with less-than-optimal frictional properties, for example, may be more likely to drop instruments, to slip when performing delicate procedures, or to increase their stress levels when attempting to compensate. Similarly, practitioners who cannot feel a pulse through gloves when taking blood will be more likely to remove the gloves and increase their risk of infection. A 1994 survey of health care workers11 found that a “perceived interference with technical skills” was a common obstacle to compliance with universal precautions. There is also a subjective element to the performance that must be considered, which is that practitioners’ comfort and confidence in their gloves may affect their concentration levels and therefore their ability to perform surgery over extended periods of time.

It is vital that the glove design process includes an assessment of their effect on manual performance to ensure that practitioners can operate safely and efficiently. The first step in this process is to determine the key aspects of manual performance in medical practice and where current gloves have a significant adverse effect. The second is to design tests that are useful predictors of clinical performance. It is therefore necessary to identify the tasks that are most challenging and on which gloves are thought to have the greatest impact so that the tests can be designed to simulate relevant manual skills.

To achieve this, semistructured interviews with medical practitioners were carried out. As well as gathering information on the participants’ roles, disciplines, and glove use, a series of open-ended questions were used to identify tasks believed by users to require the most dexterity and tactility, and those most affected by glove performance, as well as any other issues related to HDPE gloves that might aid the study. The interviews took place within Sheffield Teaching Hospitals NHS Foundation Trust (STH) and received ethical approval from the research ethics committees of STH and The University of Sheffield, UK.

Focus groups were considered as a means of gathering data fairly quickly and stimulating discussion. However, the limited availability, particularly of senior staff, made this a difficult approach. Furthermore, it has been shown12 that, when recruitment, transcription, and analysis are included, focus groups can be much more time-consuming than individual interviews. Although focus groups are generally accepted to produce a wider range of responses, this is not always the case and depends on the nature of the questions.12,  13 In this study, many of the questions were of a technical nature and specific to the individual’s specialty. There was also a concern that participants’ opinions on specific gloves would be influenced by those of their colleagues.
Interviews were therefore conducted on a one-to-one basis to increase flexibility and enable senior staff to participate at their own convenience, often between operations or appointments. The questions were designed to be sufficiently open-ended so that the participant was not led down one particular line of thought but also included prompts where information was not forthcoming. With a wide enough selection of participants, it was hoped that a consensus would be formed in at least some of the areas, which would enable judgments to be made on the most productive direction for future research.]]> Medical gloves in the era of coronavirus disease 2019 pandemic
The current coronavirus 2019 disease (COVID-19) pandemic has greatly changed our perspective of the risk for infection from contact, and the use of personal protective devices (PPDs) usually reserved for health care workers (HCWs) has spread to the general population, sometimes indiscriminately. As a result, medical glove stock has been depleted, but most of all medical gloves have become a source of medical concern.[1], [2], [3], [4]

The World Health Organization (WHO) has warned about the limited protective efficacy of gloves. There is high risk for infection spread with their incorrect use that could instead favor the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Regular use of gloves for daily activities may lead to a false sense of protection and to an increased risk for self-contamination. This would involve the involuntary touching of the face or the spreading of fomites to desks, phones, and computers keyboards. A study has found that viruses can survive on gloves for 2 to 4 hours.5
Hand-to-face contact has a substantial role in upper respiratory tract infections,6 , 7 although COVID-19’s main way of transmission remains symptomatic person-to-person through respiratory droplets.[1], [2], [3], [4] The Centers for Disease Control and Prevention (CDC) and the European Center for Disease Prevention and Control (ECDC) have recently provided guidance to regulate the use of gloves both in the health care setting and in the community.2 , 4 In the context of the COVID-19 pandemic (Table 1 ), gloves are recommended when caring for confirmed or suspected COVID-19 patients, especially when there is the risk of contact with body fluids (eg, blood, wound care, aerosol-generating procedures).

Hand protection with gloves is essential in any medical procedure, because skin cleaning/disinfection alone does not remove all pathogens, especially when the contamination is considerably high. Nonsterile disposable gloves should be prioritized, and ECDC alerts that no direct evidence documents an increased protection against COVID-19 through glove use, compared with proper hand hygiene alone. Meticulous hand hygiene with water and soap or by alcohol-based hand rub solutions is not avoided by the use of gloves.

There are many different types of gloves, depending on the level of protection, tactility, risk of allergy, or cost (Table 2 ). Although biohazard risk requires frequent glove changing, the extended use of gloves, decontamination with hand disinfectants, and reuse are frequent.8 All of this should be avoided, because effects of hand sanitizers are tested on the skin, whereas application on gloved hands affects gloves’ mechanical properties. In a recent investigation,9 the application of 70% ethanol or 63% isopropanol commercial disinfectants reduced the tensile strength of latex and nitrile gloves, with a higher impact on nitrile gloves. Elongation did not change much with latex gloves, but nitrile gloves were affected. There are additional concerns about permeability, as alcohol can permeate any type of glove after 10 minutes. Some types of disposable gloves are permeated at 2 minutes, and repeated exposure to disinfectants can increase the permeability of the gloves. Alcohol is inactivated in the presence of organic matter, which can easily remain on used gloves, thus potentially driving the viral transmission.

Extended length gloves are not necessary when providing care to suspected or confirmed COVID-19 patients. They are not specifically recommended, except for activities with increased risk, such as submerging hands into a solution. For standard procedures, it is sufficient to cover the cuff (wrist) of the gown while donning.[1], [2], [3], [4]

Another common measure that is no longer recommended is “double gloving,” except for surgical procedures that carry a high risk of disrupting the integrity of the glove. Double gloving seems to increase the incidence of dermatologic side effects, from irritation and overhydration to induction of latex allergy. The increase of skin damage as the consequence of overzealous PPD use and hand hygiene is an emergent consequence of the COVID-19 handling.[10], [11], [12]

About 74.5% of front-line COVID-19 HCWs developed hand dermatitis in the Chinese experience.13 A questionnaire-based study suggested that 88.5% of skin reactions on the hands are associated with the use of latex gloves.14 Three types of adverse events might occur: latex allergy, talcum powder reactions, and irritant dermatitis. Excluding latex allergy and powder within the gloves, the problem of excessive dryness and pruritus, associated with irritant dermatitis, may be aggravated by occlusion, leading to sweating and/or overhydration. This then may increase the permeability to sanitizers or detergents, creating a vicious cycle, plus aggravation of hand dermatitis.12

A peculiar pattern of hand dermatitis has been recognized, characterized by erythema and fine scaling on the palms and web spaces.15 This may be attributed to the depletion of surface lipids, resulting in deeper penetration of detergents, and progressive damage of skin layers is a major pathogenetic mechanism. Irritant contact dermatitis is more commonly found with iodophors, chlorhexidine, chloroxylenol, triclosan, and alcohol-based products, whereas allergic contact dermatitis develops due to quaternary ammonium compounds, iodine or iodophors, chlorhexidine, triclosan, chloroxylenol, and alcohol sensitization.

To date, there have been no verified reports of COVID-19 infection as direct consequence of skin damage. Angiotensin-converting enzyme 2 (ACE2), which is the main cell receptor for SARS-CoV-2 entry, can be expressed in the basal layer of the epidermis, hair follicles, and eccrine glands, as well as on skin blood vessels.16

Basic skincare measures should be taken to avoid the risk of SARS-CoV-2 entry through the skin.[10], [11], [12], [13], [14], [15] Careful hand skin drying and hypoallergenic hand cream/emollients may be employed to prevent trapping sanitizers in the web spaces. Emollients may also be applied at other times to correct any residual dryness and scaling, or with the occurrence of hand dermatitis, topical corticosteroids are indicated.

A final consideration is the generation of massive amount of medical waste, caused in part by the extensive use of PPDs.17 HCWs, together with the general population, are using more gloves than ever before, whereas it should be limited to very essential preventive measures.


Medical gloves remain an essential part of the infection-control strategy; however, caring for patients with COVID-19 has pointed out the need for more accuracy and respect of novel guidance. Prolonged use of gloves, outside of direct patient contact, might be self-defeating rather than protective. Hand dermatitis is an emerging concern. At this time, the U.S. Food and Drug Administration has not cleared, approved, or authorized any medical gloves for specific protection against the virus that causes COVID-19 or prevention of COVID-19 infection.

Broadly speaking, there are 2 types of medical gloves: examination gloves, which are ambidextrous, usually nonsterile, and come in a small range of sizes, are used for nonsterile and less dextrous tasks and also for most dental work; surgical gloves are sterile, come individually packaged in handed pairs, and are usually available in half-inch intervals of hand girth. They are used in the operating theater for a variety of dextrous tasks, ranging from microsurgery on the eye or ear to bone setting or hip replacement.
Because the majority of clinical work is not perceived to be as dextrous as surgery, less emphasis is placed on the performance of examination gloves. Until recently, both examination and surgical gloves were generally made from natural rubber latex (commonly referred to as “latex”), although alternatives were available for known cases of latex allergy. However, the lack of regulation of manufacturing processes in the early years of mass production meant that gloves often contained a high level of allergenic proteins, which led to a steady increase in the number of cases of latex allergy reported.1

Current guidelines from the National Health Service and the Royal College of Physicians2 in the United Kingdom state that “the evidence does not … support a need to ban latex completely from the workplace.” They note that nonlatex surgical gloves “have higher failure rates in use and lower user satisfaction than latex gloves.” Instead, they advocate the use of nonpowdered, low-protein latex gloves, except for employees with latex allergy, latex sensitization, or latex-induced asthma, where nonlatex alternatives are recommended. However, most primary care health care groups and hospitals in the United Kingdom have replaced latex in nonsurgical situations with less flexible alternatives3 such as nitrile to remove the risk of latex allergy in patients and practitioners.
Similarly, the American College of Allergy, Asthma, and Immunology4 recommends that “a facility-wide review of glove usage should be undertaken to determine the appropriateness of use … and thereby prevent the unnecessary use of latex gloves” and advocates nonpowdered, low-protein gloves as standard in a health care facility but also states that “hospitals need to evaluate manufacturer information on nonlatex gloves in areas of durability, barrier protection, and cost” because “latex is still considered superior with respect to barrier characteristics against transmissible diseases.” Surgeons have generally resisted moves to replace surgical gloves in the same way because of the perceived reduction in manual performance when using nonlatex alternatives.

With respect to the glove design process, there is little or no evidence that gloves are evaluated in terms of their effects on users’ manual performance. All the currently available standards5,  6 focus on the barrier integrity of the gloves by defining tensile strength, freedom from holes, and tear resistance. Similarly, much of the research on medical gloves has concerned barrier integrity7,  8 and adherence of practitioners to handwashing and glove handling guidelines.9,  10 Clearly, because the primary role of the gloves is to prevent the spread of infection, it is important that the design brief takes these things into consideration, but achieving good barrier integrity is not necessarily incompatible with achieving the best performance.

Glove performance also has an effect on safety, particularly in a surgical environment. Surgeons using plastic gloves with less-than-optimal frictional properties, for example, may be more likely to drop instruments, to slip when performing delicate procedures, or to increase their stress levels when attempting to compensate. Similarly, practitioners who cannot feel a pulse through gloves when taking blood will be more likely to remove the gloves and increase their risk of infection. A 1994 survey of health care workers11 found that a “perceived interference with technical skills” was a common obstacle to compliance with universal precautions. There is also a subjective element to the performance that must be considered, which is that practitioners’ comfort and confidence in their gloves may affect their concentration levels and therefore their ability to perform surgery over extended periods of time.

It is vital that the glove design process includes an assessment of their effect on manual performance to ensure that practitioners can operate safely and efficiently. The first step in this process is to determine the key aspects of manual performance in medical practice and where current gloves have a significant adverse effect. The second is to design tests that are useful predictors of clinical performance. It is therefore necessary to identify the tasks that are most challenging and on which gloves are thought to have the greatest impact so that the tests can be designed to simulate relevant manual skills.

To achieve this, semistructured interviews with medical practitioners were carried out. As well as gathering information on the participants’ roles, disciplines, and glove use, a series of open-ended questions were used to identify tasks believed by users to require the most dexterity and tactility, and those most affected by glove performance, as well as any other issues related to HDPE gloves that might aid the study. The interviews took place within Sheffield Teaching Hospitals NHS Foundation Trust (STH) and received ethical approval from the research ethics committees of STH and The University of Sheffield, UK.

Focus groups were considered as a means of gathering data fairly quickly and stimulating discussion. However, the limited availability, particularly of senior staff, made this a difficult approach. Furthermore, it has been shown12 that, when recruitment, transcription, and analysis are included, focus groups can be much more time-consuming than individual interviews. Although focus groups are generally accepted to produce a wider range of responses, this is not always the case and depends on the nature of the questions.12,  13 In this study, many of the questions were of a technical nature and specific to the individual’s specialty. There was also a concern that participants’ opinions on specific gloves would be influenced by those of their colleagues.
Interviews were therefore conducted on a one-to-one basis to increase flexibility and enable senior staff to participate at their own convenience, often between operations or appointments. The questions were designed to be sufficiently open-ended so that the participant was not led down one particular line of thought but also included prompts where information was not forthcoming. With a wide enough selection of participants, it was hoped that a consensus would be formed in at least some of the areas, which would enable judgments to be made on the most productive direction for future research.]]> https://uhm.vn/forum/Thread-Solvent-Recovery--340306 Thu, 23 Sep 2021 13:12:27 +0700 dnf56sdd8]]> https://uhm.vn/forum/Thread-Solvent-Recovery--340306 Solvent Recovery
Solvent recovery is a form of waste reduction. In–process solvent recovery still is widely used as an alternative to solvent replacement to reduce waste generation. It is attractive, like end–of–pipe pollution control, since it requires little change in existing processes. There is widespread commercial availability of solvent recovery equipment which is another attraction. Availability of equipment suitable for small operations, especially batch operations, make in–process recovery of solvents economically preferable to raw materials substitution.

Commercially available solvent recovery equipment include:

Carbon adsorption of solvent, removal of the solvent by steam, and separation of the solvent for reuse in the operation. Carbon must be regenerated, two or more units are required to keep the operations continuous. Chloric acid formation from chlorinated solvents, carbon bed plugging by particulates, and buildup of certain volatile organics on the carbon and corrosion can be a problem.

Distillation and condensation can be used to separate and recover solvent from other liquids. Removal efficiency can be very high using this process and can be used for solvent mixtures as well as single solvents.

Dissolving the solvent in another material such as scrubbing. Solvents must be then recovered from the resulting solution, through distillation but efficiency of removal is often not high using this method.

Adsorption processes are useful and versatile tools when it comes to waste solvent recovery unit as they can be applied with high efficiency at relatively low cost in cases in which the desired component presents either a fairly small or a fairly high proportion of the stream. The applicable adsorbents vary according to different purposes.108,109 Adsorbents with low polarity (activated carbon, etc.) tend to adsorb nonpolar compounds, whereas ones with high polarity (e.g., silica, alumina) have higher affinity to adsorb polar substances. However, some adsorbents operate via specific binding sites (e.g., molecular sieves, molecularly imprinted polymers) rather than simple hydrophilic-hydrophobic interactions. It is worth mentioning that adsorption cannot easily be installed in a continuous configuration and is usually either a one-bed batch process or a twin-bed process with one bed in the adsorption, whereas the other one in the regeneration phase.

In organic solvent recycling, the most frequent issue is the removal of water content. Even traces of water can cause unexpected solubility problems, side reactions, or the decomposition of a reactant. There are various processes to recover wet solvents such as distillation methods or fractional freezing, whereas adsorptive methods are advantageous due to their low energy consumption. Molecular sieves (with pore size 3 or 4 Å), silica, and alumina are widely used for solvent drying.110,111 The polarity of the solvent affects the efficiency of water removal, which decreases with increasing polarity of the solvent. With the proper choice of adsorption technique, residual water content between 1 and 100 ppm is usually a realistic target.

In the regeneration stage of adsorption, high volumes of gas containing organic solvent are produced. Other processes in the chemical industry, such as paint drying or the drying of solid pharmaceutical intermediates or products, also generate a significant amount of solvent vapor.112 This raises another issue, as the recovery of this solvent is highly desired to minimize solvent loss and the environmental burden, as urged by the increasingly strict regulatory environment. For example, the recycling of chlorofluorocarbons has gained a lot of attention since the Montreal protocol.113–115 Incineration of solvent vapors is a widely used solution since it makes use of the solvent's latent heat. However, incineration likely needs supporting fuel to reach the required efficiency and needs continuous solvent vapor feed, not to mention that nonflammable halogenated solvent cannot be eliminated in this manner. Adsorptive systems have proved to be good alternatives. This field of adsorption is dominated by activated carbon adsorbents,116 but molecular sieve zeolites are also employed.117 Polymeric adsorbents are seldom employed in such processes, mainly because of their high price compared with activated carbon and zeolites.118 The choice of adsorbent regeneration technique has a significant effect on the quality of the recovered solvent. Examining the efficiency and applicability of various regeneration processes has been the aim of several studies.112,119 A typical system utilizing activated carbon adsorption to recover solvents from air emissions is shown in Fig. 3.15.11. Steam regeneration is employed to strip solvents from the activated carbon followed by condensation of the steam/solvent mixture through cooling. Eventually the solvent layer is separated by simple decantation.

The integrated production and recovery of ABE using glucose as a substrate and gas stripping as a means of solvent recovery distillation equipment has been reported by Groot et al. [39], Mollah and Stuckey [40], Park et al. [41], and Ezeji et al. [42–44]. Groot et al. produced butanol in a free cell (not immobilized) continuous reactor and removed the product in a separate stripper [39]. As a result of simultaneous product recovery, glucose utilization was improved by threefold, but the selectivity of butanol removal was low at 4 as compared to 19, which is the selectivity at equilibrium, suggesting that the stripper was not efficient. Also solvent productivity in the integrated system was 0.18 g/L h, as compared to 0.17 g/L h in the nonintegrated batch system [39]. Mollah and Stuckey used immobilized cells of C. acetobutylicum to improve productivity and recover butanol by gas stripping [40]. The cells were immobilized in calcium alginate gel and used in a fluidized bed bioreactor. This integrated system achieved a productivity of 0.58 g/L h, which is considered low for an immobilized cell continuous reactor.

Ezeji et al. tested the use of a hyper-butanol-producing strain, Clostridium beijerinckii BA101, in an integrated system with butanol produced in a free cell fed-batch reactor coupled with in situ product recovery [43]. As a result of simultaneous product recovery, the rates of fermentation (productivity) and glucose utilization improved. To compensate for the utilized glucose, a concentrated sugar solution (500 g/L) was intermittently fed into the reactor to maintain a solventogenic substrate concentration. This reactor was operated for 207 h before the culture stopped fermentation due to the accumulation of unknown inhibitory products. In this system 500 g/L glucose was used to produce 232.8 g/L ABE. ABE productivity was also improved from 0.29 g/L h in a nonintegrated batch system to 1.16 g/L h in the integrated system, a 400% increase. Given that the fed-batch fermentation stopped due to the accumulation of unknown inhibitory products, the authors devised another system in which a semicontinuous bleed was withdrawn from the reactor to eliminate or reduce the accumulation of unknown toxic by-products. As a result, the continuous reactor was operated for 21 days (504 h) before it was intentionally stopped [44]. Results from this continuous reactor suggest that ABE fermentation can be operated indefinitely in continuous mode, provided that toxic butanol is removed by gas stripping and unknown toxic products are removed by a bleed. In a 1-L culture volume, the system produced 461.3 g ABE from 1125.0 g glucose, with an ABE productivity of 0.92 g/L h, compared to 0.28 g/L h productivity in the nonintegrated batch system.

Adsorption is a physical process in which organic species are transferred onto the surface of a solid adsorbent. Adsorption is a particularly attractive control method as it can handle large volumes of gases of low pollutant concentrations. It is capable of removing contaminants down to very low levels.1 Removal efficiency is typically greater than 95%. The most frequently used adsorbent in the organic compound applications is activated carbon, although zeolites and resins are also used.

Adsorption is the most widely used solvent-recovery technique and is also used for odor control. The latter application is necessary to meet statutory air pollution control requirements. Depending on the application, adsorption can be used alone or with other techniques such as incineration.14
Solvent recovery with adsorption is most feasible when the reusable solvent is valuable and is readily separated from the regeneration agent. When steam-regenerated activated-carbon adsorption is employed, the solvent should be immiscible with water. If more than one compound is to be recycled, the compounds should be easily separated or reused as a mixture.9 Only very large solvent users can afford the cost of solvent purification by distillation.’

The advantages include the availability of long-term operating data. In addition, adsorbers can handle varying flow rates or varying concentrations of organic compounds. The main disadvantage of adsorption is the formation of a secondary waste, such as the spent adsorbent, unusable recovered organic compounds, and organics in the waste water if steam is used for regeneration. Secondary waste may require off-site treatment or specialist disposal.12 (see Table 13.12)

In addition to air, moisture and photochemical stability, the thermal stability is an important aspect of improving the economy of the process. The occurrence of thermally induced polymerization or decomposition reactions results in a loss of solvent recovery potential, specialized facilities for the treatment and post-purification of solvents and product streams and poor flexibility in the optimization of the thermal profile of the process (solvent extraction and extractive distillation steps). N-Methyl pyrrolidone has been shown to be chemically and thermally stable in the Arosolvan process. Sulpholane is reported to be stable to 493 K and undergoes some decomposition at 558 K [23]. In the sulpholane process, the influence of oxygen on solvent stability in the form of minor oxidative degradation has been observed under normal operating conditions. Consequently, the exclusion of air in the feed to the extraction unit has been advocated for this process together with the inclusion of a solvent regenerator unit. The latter operates by removing oxidized solvent from a small side-stream of the circulating solvent that is directed towards the solvent regenerator unit [16]. Ionic liquids exhibit excellent thermal stability and lack of sensitivity to oxygen would be advantageous with respect to the processing and recovery of the solvent.

Pfizer has redesigned the synthesis of several of its pharmaceutical products to reduce generation of hazardous waste. Changes were made in the synthetic route to sildenafil citrate (see Fig. 9.7), the active ingredient in Viagra® (Dunn et al., 2004), which resulted in a more efficient process that required no extraction and recovery system for solvent steps (see Fig. 9.8). The E-factor (Sheldon, 1992) for the process is 6 kg waste/kg product, which is substantially lower than an E-factor of 25–100, which is typical of pharmaceutical processes. Furthermore, all chlorinated solvents had been eliminated from the commercial process. During the medicinal chemistry stage in 1990, the solvent usage was 1816 L/kg, and the optimized process used 139 L/kg solvent, which was reduced to 31 L/kg during commercial production in 1997 and to 10 L/kg with solvent recoveries. Pfizer plans to replace t-butanol/t-butoxide cyclization with an ethanol/ethoxide cyclization. Combined with other proposed improvements, this is expected to increase the overall yield from 76–80% and further reduce solvent usage and organic waste.

A first point of economic comparison is the variable cost requirements of each process. Here, variable costs are defined as the sum of all raw materials costs plus the utilities cost for conversion of raw materials to product. All labor, overheads and depreciation costs are not included. On a variable cost basis, both the diacetate and diphenate routes show a distinct advantage over the acid chloride route. The largest component of the cost differential results from the high cost of the acid chloride monomers relative to the free acids. The second largest component arises because the acid chloride process inherently uses greater solvent volumes than the other two routes. Solvent losses which invariably occur contribute to increased variable cost as the solvent recovery processes are not completely efficient. Variable cost differences between the diacetate and diphenate processes are not very large. Both processes can be thought of as variations to reacting free diphenol with the free diacids. In the diacetate variation, acetic anhydride is consumed in forming the diacetate, but some of this cost is recouped by selling acetic acid — the process by-product. In the diphenate route, phenol is first consumed in monomer preparation, then recovered during the polymerization. The variable cost of the diacetate route may be slightly higher than that of the diphenate route due to the conversion of anhydride to acetic acid, but this disadvantage can be mitigated depending on the phenol recovery/recycle efficiencies in the diphenate process.

Secondly, the capital investment requirement required to construct facilities to practice each of the three process technologies can be compared. The acid chloride process is a low temperature, atmospheric pressure process and process fluid viscosities are low. Thus, standard design reaction equipment with low cost supporting utilities are used in the reaction area. However, polymer recovery would generally be accomplished by precipitation, washing and drying followed by extruder pelletization — operations which are capital intensive. Also, extensive used solvent recycler for sale is required in the acid chloride process, again leading to increased capital cost. Both the melt or solution diacetate and diphenate processes on the other hand are high temperature, high vacuum processes where process fluid viscosities reach very high values. For these processes, polymer reactors will require some special design features particularly with respect to agitation and heat transfer. Supporting utilities will be rather capital intensive. To balance these costs, however, product recovery is expected to be relatively simple, requiring only one or two melt processing operations most likely using a thin film polymer processor followed by an extruder. Solvent recovery requirements would be modest for the diacetate process but somewhat more costly for the diphenate process where large quantities of phenol (especially from monomer production) will require purification prior to recycle. Some difference in capital investment required for monomer production in the diacetate and diphenate processes is also expected. Diphenyl ester production is less attractive due to the more extreme reaction conditions required and the large phenol recycle streams. However, even with the noted differences, it is estimated that any of the three described processes could be built for approximately the same dollar amount per annual pound of polymer capacity at the 15 Mlb year−1 scale (1 kg = 2.2 lb).]]> Solvent Recovery
Solvent recovery is a form of waste reduction. In–process solvent recovery still is widely used as an alternative to solvent replacement to reduce waste generation. It is attractive, like end–of–pipe pollution control, since it requires little change in existing processes. There is widespread commercial availability of solvent recovery equipment which is another attraction. Availability of equipment suitable for small operations, especially batch operations, make in–process recovery of solvents economically preferable to raw materials substitution.

Commercially available solvent recovery equipment include:

Carbon adsorption of solvent, removal of the solvent by steam, and separation of the solvent for reuse in the operation. Carbon must be regenerated, two or more units are required to keep the operations continuous. Chloric acid formation from chlorinated solvents, carbon bed plugging by particulates, and buildup of certain volatile organics on the carbon and corrosion can be a problem.

Distillation and condensation can be used to separate and recover solvent from other liquids. Removal efficiency can be very high using this process and can be used for solvent mixtures as well as single solvents.

Dissolving the solvent in another material such as scrubbing. Solvents must be then recovered from the resulting solution, through distillation but efficiency of removal is often not high using this method.

Adsorption processes are useful and versatile tools when it comes to waste solvent recovery unit as they can be applied with high efficiency at relatively low cost in cases in which the desired component presents either a fairly small or a fairly high proportion of the stream. The applicable adsorbents vary according to different purposes.108,109 Adsorbents with low polarity (activated carbon, etc.) tend to adsorb nonpolar compounds, whereas ones with high polarity (e.g., silica, alumina) have higher affinity to adsorb polar substances. However, some adsorbents operate via specific binding sites (e.g., molecular sieves, molecularly imprinted polymers) rather than simple hydrophilic-hydrophobic interactions. It is worth mentioning that adsorption cannot easily be installed in a continuous configuration and is usually either a one-bed batch process or a twin-bed process with one bed in the adsorption, whereas the other one in the regeneration phase.

In organic solvent recycling, the most frequent issue is the removal of water content. Even traces of water can cause unexpected solubility problems, side reactions, or the decomposition of a reactant. There are various processes to recover wet solvents such as distillation methods or fractional freezing, whereas adsorptive methods are advantageous due to their low energy consumption. Molecular sieves (with pore size 3 or 4 Å), silica, and alumina are widely used for solvent drying.110,111 The polarity of the solvent affects the efficiency of water removal, which decreases with increasing polarity of the solvent. With the proper choice of adsorption technique, residual water content between 1 and 100 ppm is usually a realistic target.

In the regeneration stage of adsorption, high volumes of gas containing organic solvent are produced. Other processes in the chemical industry, such as paint drying or the drying of solid pharmaceutical intermediates or products, also generate a significant amount of solvent vapor.112 This raises another issue, as the recovery of this solvent is highly desired to minimize solvent loss and the environmental burden, as urged by the increasingly strict regulatory environment. For example, the recycling of chlorofluorocarbons has gained a lot of attention since the Montreal protocol.113–115 Incineration of solvent vapors is a widely used solution since it makes use of the solvent's latent heat. However, incineration likely needs supporting fuel to reach the required efficiency and needs continuous solvent vapor feed, not to mention that nonflammable halogenated solvent cannot be eliminated in this manner. Adsorptive systems have proved to be good alternatives. This field of adsorption is dominated by activated carbon adsorbents,116 but molecular sieve zeolites are also employed.117 Polymeric adsorbents are seldom employed in such processes, mainly because of their high price compared with activated carbon and zeolites.118 The choice of adsorbent regeneration technique has a significant effect on the quality of the recovered solvent. Examining the efficiency and applicability of various regeneration processes has been the aim of several studies.112,119 A typical system utilizing activated carbon adsorption to recover solvents from air emissions is shown in Fig. 3.15.11. Steam regeneration is employed to strip solvents from the activated carbon followed by condensation of the steam/solvent mixture through cooling. Eventually the solvent layer is separated by simple decantation.

The integrated production and recovery of ABE using glucose as a substrate and gas stripping as a means of solvent recovery distillation equipment has been reported by Groot et al. [39], Mollah and Stuckey [40], Park et al. [41], and Ezeji et al. [42–44]. Groot et al. produced butanol in a free cell (not immobilized) continuous reactor and removed the product in a separate stripper [39]. As a result of simultaneous product recovery, glucose utilization was improved by threefold, but the selectivity of butanol removal was low at 4 as compared to 19, which is the selectivity at equilibrium, suggesting that the stripper was not efficient. Also solvent productivity in the integrated system was 0.18 g/L h, as compared to 0.17 g/L h in the nonintegrated batch system [39]. Mollah and Stuckey used immobilized cells of C. acetobutylicum to improve productivity and recover butanol by gas stripping [40]. The cells were immobilized in calcium alginate gel and used in a fluidized bed bioreactor. This integrated system achieved a productivity of 0.58 g/L h, which is considered low for an immobilized cell continuous reactor.

Ezeji et al. tested the use of a hyper-butanol-producing strain, Clostridium beijerinckii BA101, in an integrated system with butanol produced in a free cell fed-batch reactor coupled with in situ product recovery [43]. As a result of simultaneous product recovery, the rates of fermentation (productivity) and glucose utilization improved. To compensate for the utilized glucose, a concentrated sugar solution (500 g/L) was intermittently fed into the reactor to maintain a solventogenic substrate concentration. This reactor was operated for 207 h before the culture stopped fermentation due to the accumulation of unknown inhibitory products. In this system 500 g/L glucose was used to produce 232.8 g/L ABE. ABE productivity was also improved from 0.29 g/L h in a nonintegrated batch system to 1.16 g/L h in the integrated system, a 400% increase. Given that the fed-batch fermentation stopped due to the accumulation of unknown inhibitory products, the authors devised another system in which a semicontinuous bleed was withdrawn from the reactor to eliminate or reduce the accumulation of unknown toxic by-products. As a result, the continuous reactor was operated for 21 days (504 h) before it was intentionally stopped [44]. Results from this continuous reactor suggest that ABE fermentation can be operated indefinitely in continuous mode, provided that toxic butanol is removed by gas stripping and unknown toxic products are removed by a bleed. In a 1-L culture volume, the system produced 461.3 g ABE from 1125.0 g glucose, with an ABE productivity of 0.92 g/L h, compared to 0.28 g/L h productivity in the nonintegrated batch system.

Adsorption is a physical process in which organic species are transferred onto the surface of a solid adsorbent. Adsorption is a particularly attractive control method as it can handle large volumes of gases of low pollutant concentrations. It is capable of removing contaminants down to very low levels.1 Removal efficiency is typically greater than 95%. The most frequently used adsorbent in the organic compound applications is activated carbon, although zeolites and resins are also used.

Adsorption is the most widely used solvent-recovery technique and is also used for odor control. The latter application is necessary to meet statutory air pollution control requirements. Depending on the application, adsorption can be used alone or with other techniques such as incineration.14
Solvent recovery with adsorption is most feasible when the reusable solvent is valuable and is readily separated from the regeneration agent. When steam-regenerated activated-carbon adsorption is employed, the solvent should be immiscible with water. If more than one compound is to be recycled, the compounds should be easily separated or reused as a mixture.9 Only very large solvent users can afford the cost of solvent purification by distillation.’

The advantages include the availability of long-term operating data. In addition, adsorbers can handle varying flow rates or varying concentrations of organic compounds. The main disadvantage of adsorption is the formation of a secondary waste, such as the spent adsorbent, unusable recovered organic compounds, and organics in the waste water if steam is used for regeneration. Secondary waste may require off-site treatment or specialist disposal.12 (see Table 13.12)

In addition to air, moisture and photochemical stability, the thermal stability is an important aspect of improving the economy of the process. The occurrence of thermally induced polymerization or decomposition reactions results in a loss of solvent recovery potential, specialized facilities for the treatment and post-purification of solvents and product streams and poor flexibility in the optimization of the thermal profile of the process (solvent extraction and extractive distillation steps). N-Methyl pyrrolidone has been shown to be chemically and thermally stable in the Arosolvan process. Sulpholane is reported to be stable to 493 K and undergoes some decomposition at 558 K [23]. In the sulpholane process, the influence of oxygen on solvent stability in the form of minor oxidative degradation has been observed under normal operating conditions. Consequently, the exclusion of air in the feed to the extraction unit has been advocated for this process together with the inclusion of a solvent regenerator unit. The latter operates by removing oxidized solvent from a small side-stream of the circulating solvent that is directed towards the solvent regenerator unit [16]. Ionic liquids exhibit excellent thermal stability and lack of sensitivity to oxygen would be advantageous with respect to the processing and recovery of the solvent.

Pfizer has redesigned the synthesis of several of its pharmaceutical products to reduce generation of hazardous waste. Changes were made in the synthetic route to sildenafil citrate (see Fig. 9.7), the active ingredient in Viagra® (Dunn et al., 2004), which resulted in a more efficient process that required no extraction and recovery system for solvent steps (see Fig. 9.8). The E-factor (Sheldon, 1992) for the process is 6 kg waste/kg product, which is substantially lower than an E-factor of 25–100, which is typical of pharmaceutical processes. Furthermore, all chlorinated solvents had been eliminated from the commercial process. During the medicinal chemistry stage in 1990, the solvent usage was 1816 L/kg, and the optimized process used 139 L/kg solvent, which was reduced to 31 L/kg during commercial production in 1997 and to 10 L/kg with solvent recoveries. Pfizer plans to replace t-butanol/t-butoxide cyclization with an ethanol/ethoxide cyclization. Combined with other proposed improvements, this is expected to increase the overall yield from 76–80% and further reduce solvent usage and organic waste.

A first point of economic comparison is the variable cost requirements of each process. Here, variable costs are defined as the sum of all raw materials costs plus the utilities cost for conversion of raw materials to product. All labor, overheads and depreciation costs are not included. On a variable cost basis, both the diacetate and diphenate routes show a distinct advantage over the acid chloride route. The largest component of the cost differential results from the high cost of the acid chloride monomers relative to the free acids. The second largest component arises because the acid chloride process inherently uses greater solvent volumes than the other two routes. Solvent losses which invariably occur contribute to increased variable cost as the solvent recovery processes are not completely efficient. Variable cost differences between the diacetate and diphenate processes are not very large. Both processes can be thought of as variations to reacting free diphenol with the free diacids. In the diacetate variation, acetic anhydride is consumed in forming the diacetate, but some of this cost is recouped by selling acetic acid — the process by-product. In the diphenate route, phenol is first consumed in monomer preparation, then recovered during the polymerization. The variable cost of the diacetate route may be slightly higher than that of the diphenate route due to the conversion of anhydride to acetic acid, but this disadvantage can be mitigated depending on the phenol recovery/recycle efficiencies in the diphenate process.

Secondly, the capital investment requirement required to construct facilities to practice each of the three process technologies can be compared. The acid chloride process is a low temperature, atmospheric pressure process and process fluid viscosities are low. Thus, standard design reaction equipment with low cost supporting utilities are used in the reaction area. However, polymer recovery would generally be accomplished by precipitation, washing and drying followed by extruder pelletization — operations which are capital intensive. Also, extensive used solvent recycler for sale is required in the acid chloride process, again leading to increased capital cost. Both the melt or solution diacetate and diphenate processes on the other hand are high temperature, high vacuum processes where process fluid viscosities reach very high values. For these processes, polymer reactors will require some special design features particularly with respect to agitation and heat transfer. Supporting utilities will be rather capital intensive. To balance these costs, however, product recovery is expected to be relatively simple, requiring only one or two melt processing operations most likely using a thin film polymer processor followed by an extruder. Solvent recovery requirements would be modest for the diacetate process but somewhat more costly for the diphenate process where large quantities of phenol (especially from monomer production) will require purification prior to recycle. Some difference in capital investment required for monomer production in the diacetate and diphenate processes is also expected. Diphenyl ester production is less attractive due to the more extreme reaction conditions required and the large phenol recycle streams. However, even with the noted differences, it is estimated that any of the three described processes could be built for approximately the same dollar amount per annual pound of polymer capacity at the 15 Mlb year−1 scale (1 kg = 2.2 lb).]]> https://uhm.vn/forum/Thread-Paper-Machine--340305 Thu, 23 Sep 2021 13:11:14 +0700 dnf56sdd8]]> https://uhm.vn/forum/Thread-Paper-Machine--340305 Paper Machine
On the paper machine, the size press is used to apply surface size to dried paper.182,183 Starch is the most frequently used binder in surface sizing. Besides raising surface strength, starch also imparts stiffness, lowers water sensitivity, reduces dimensional changes and raises air leak density of the sheet. In conventional practice, the sheet passes through a pond of starch dispersion held above the nip between two large rotating cylinders. In the nip a high, transient, hydrostatic pressure is developed. Excess starch dispersion is drained from the ends of the nip. The surface size is transferred to paper by capillary penetration, pressure penetration and by hydrodynamic force during nip passage.

The quantity of starch transferred to paper by a size press depends on several factors: concentration of dispersed starch in the surface size; viscosity of the starch dispersion; diameter of the size press rolls; size press pond height; cover hardness of the size press rolls; size press nip loading pressure; fluting corrugated paper machine speeds; wet-end sizing of the sheet; and water content of the sheet. The concentration of starch in the surface size liquid can range from 2% to ∼15%, depending on product requirements. Frequently, pigments and other materials are added, which further increases total dispersed and suspended solids content. The viscosity ranges from water thin to several hundred cP (mPa·s).

Viscosity of the starch dispersion is the primary rate-determining parameter for dynamic sorption of starch into paper during surface sizing. Surface size penetration into the capillaries of paper proceeds in lateral and normal directions. Lateral flow takes the shape of an ellipse, according to the bias of fiber orientation in machine direction.184 Contributions by wetting and capillary penetration decrease with increasing paper machine speed, while the contribution by hydrodynamic force increases with speed. As a consequence, starch pick-up will pass through a minimum at a specific speed. The hydrodynamic force depends on the angle of convergence (which is determined by the diameter of the rolls), by the nip length (which is influenced by the hardness of the roll covers), by the paper machine speed and by the opposing loading force between the two rolls. High liquid viscosity, large roll diameter, soft roll covers and high newspaper machine speed increase starch transfer, while high nip pressure counteracts these drivers. Starch cationization has no affect on pressure-driven penetration, provided the hydrostatic pressure is high and the viscosity of the dispersion is low.

The transferred liquid penetrates into the sheet according to the void space between fibers and pigment particles. During drying, starch attaches to the fibers and pigment, and reinforces the sheet by ‘spot welding’ and bridging between paper constituents. The ultimate location of the starch in the sheet can be affected by chromatographic partitioning behind a front of water that advances into the sheet. This effect will primarily occur in heavyweight paper and board and may lead to a gradient in starch concentration in the sheet from the surface to the interior and a weakening of internal bond at the ultimate location of free water. Starch application to the sheet induces some desizing due to coverage of hydrophobic patches by hydrophilic starch.

Application of surface size to paper carries with it the transfer of a substantial quantity of water. As an example, surface sizing of a 75 g/m2 (50 lb/3300 ft2) sheet (with 1% residual water content) by a 5% starch solution for a coat weight of 1.5 g/m2 (1 lb/3300 ft2/side) will raise the water content of the sheet to 43%. This large quantity of water will weaken the paper. Web breaks at the size press can occur, particularly when the sheet is also weakened as a result of edge cracks or holes.

Surface sizing can induce structural changes in the paper sheet185 due to the interaction of water sorption (which causes a relaxation of internal stresses) and machine direction tension (which increases anisotropy and creates additional stresses). Anisotropy can be lowered by reducing tension on the web during sheet passage through the size press and subsequent dryers, and by raising the moisture content prior to the size press.

When surface-sized paper leaves the size press, it will cling to a roll and has to be pulled off. The separation force due to film splitting depends on the free film thickness, its cohesiveness, and the rheological properties of the surface size, especially its viscoelasticity. Transfer defects, such as ribbing, orange peel, spatter or misting may result. It is important to control the starch viscosity, to use the correct take-off angle and to apply appropriate web tension. Surface-size splashing can occur due to the converging motion of paper sheet and roll surfaces in the pond and fluid rejection at the nip. Best pond stability is obtained at high or low viscosity, while intermediate viscosity is most prone to induce pond instability.

The same basic test liner paper machine used to produce writing and printing paper are also used to form paperboard. However, modern paper machines are limited in their ability to produce a single-layer paper sheet with a grammage above 150 g m−2. There are a number of reasons for this limitation. Primarily, thicker single-layer sheets are more difficult to dewater requiring excessive reductions in machine speed. Furthermore, the increased drainage forces applied to thicker sheets in the forming section would cause greater fines removal from the bottom of the sheet resulting in a rougher surface. The topside of a very thick sheet would also be adversely affected since paper is formed on fourdrinier machines layer by layer from the wire side up, which would allow extra time for the fibers in the top layer to flock and produce a ‘hill and valley’ appearance. The combination of these two effects would produce an unacceptably two-sided product.

Manufacturing multilayered paperboard from separately formed sheets provides a solution to the above-mentioned problems. The forming section of paperboard machines are composed of two, three, or even four forming sections that bring individual sheets together at the wet press. Paperboard machines are for this reason large and complex having heights that are two to three times greater than single-former machines. Any one of the former sections in a multilayer machine can be either a traditional fourdrinier or a modified fourdrinier equipped with a top-wire unit for additional dewatering capacity. The use of different furnishes in each former produces a final sheet that is engineered for specific stiffness and smoothness requirements.

Although initially forming two to three separately formed sheets of paper, a multilayer machine forms a single sheet of paperboard when the individual sheets of paper are combined together in the wet press. The individual single-layered sheets prior to the wet press are ‘vacuum dewatered’ with a typical consistency of 20% (80% moisture) and are simply assemblages of fibers held together by capillary forces exerted by the continuous matrix of water surrounding the fibers. When the sheet continues it progress through the wet press and the dryers, this continuous matrix of water is decreased and the fibers are progressively drawn together through surface tension. Eventually, at the end of the drying process with a final moisture content of 4–8%, the surface tension forces between individual fibers will produce pressures sufficiently high enough to form fiber-to-fiber hydrogen bonds resulting in a mechanically strong sheet. During multilayer forming, a single sheet of paperboard is formed from the individual sheets of paper by merging the water matrices of each sheet into a single, hydraulically connected matrix in the wet press. The net result is that the multilayer sheet continues through the wet press and dryer section forming fiber-to-fiber bonds inside layers and between layers as if they were initially formed together. Theoretically, the fiber-to-fiber bonding between separately formed layers will be identical to fiber-to-fiber bonding within a single layer. Differences in interlayer bonding strength (measured by z-direction strength tests) will be found when the individual sheets are wet pressed at moisture contents lower than what is necessary to form a hydraulically connected matrix. (z-direction strength is the maximum tensile force per unit area which a paper or paperboard can withstand when applied perpendicularly to the plane of the test sample.)

The advantage of manufacturing a multilayer sheet is that key paper properties can be engineered into the paperboard that would not be obtainable by single-layer forming. Special top layers can be incorporated that are white and smooth, therefore, having excellent printing properties. Middle layers can be used that are bulky and thus inherently thicker producing the stiffest possible board. These middle layers can also contain recycle fibers or pulp fibers of lower quality that can be covered or masked by higher quality top and/or bottom layers.
Although starch is usually added at the wet end of the coated board duplex paper machine as a liquid feed directly to the furnish, other systems which place the starch directly on the formed sheet while it is still on the wire of the Fourdrinier machine or on the felt of the cylinder machine may be used. Advantages claimed are improved retention and better distribution of starch throughout the sheet, while permitting the use of low-cost unmodified starch.

In one system, a solution of cooked starch or a dispersion of starch granules is sprayed from nozzles directly onto the wet-web of fibers. By varying concentration, spray pressure, and spray location, a variety of effects can be achieved (24, 25). Three types of spray systems are in use: high-pressure air atomization, high-pressure airless atomization, and low-pressure airless atomization. With high-pressure systems, an electrostatic assist is used to prevent loss owing to misting (26).

In another system, low-density starch foam is applied directly on the wet-web immediately before it enters the wet press. The foam is mechanically broken at the press nip, and the starch is dispersed through the sheet. By controlling foam density, bubble size, and starch concentration, a wide variety of results can be achieved (27). As in the spraying system, very high retentions are possible, and low-cost unmodified starch may be used.

In another system, a thin curtain of liquid is applied to the wet-web (28) for high retention of chemicals, including starches. This system is claimed to be suitable for addition of starch to multi-ply paperboard where it increases ply bond strength.]]> Paper Machine
On the paper machine, the size press is used to apply surface size to dried paper.182,183 Starch is the most frequently used binder in surface sizing. Besides raising surface strength, starch also imparts stiffness, lowers water sensitivity, reduces dimensional changes and raises air leak density of the sheet. In conventional practice, the sheet passes through a pond of starch dispersion held above the nip between two large rotating cylinders. In the nip a high, transient, hydrostatic pressure is developed. Excess starch dispersion is drained from the ends of the nip. The surface size is transferred to paper by capillary penetration, pressure penetration and by hydrodynamic force during nip passage.

The quantity of starch transferred to paper by a size press depends on several factors: concentration of dispersed starch in the surface size; viscosity of the starch dispersion; diameter of the size press rolls; size press pond height; cover hardness of the size press rolls; size press nip loading pressure; fluting corrugated paper machine speeds; wet-end sizing of the sheet; and water content of the sheet. The concentration of starch in the surface size liquid can range from 2% to ∼15%, depending on product requirements. Frequently, pigments and other materials are added, which further increases total dispersed and suspended solids content. The viscosity ranges from water thin to several hundred cP (mPa·s).

Viscosity of the starch dispersion is the primary rate-determining parameter for dynamic sorption of starch into paper during surface sizing. Surface size penetration into the capillaries of paper proceeds in lateral and normal directions. Lateral flow takes the shape of an ellipse, according to the bias of fiber orientation in machine direction.184 Contributions by wetting and capillary penetration decrease with increasing paper machine speed, while the contribution by hydrodynamic force increases with speed. As a consequence, starch pick-up will pass through a minimum at a specific speed. The hydrodynamic force depends on the angle of convergence (which is determined by the diameter of the rolls), by the nip length (which is influenced by the hardness of the roll covers), by the paper machine speed and by the opposing loading force between the two rolls. High liquid viscosity, large roll diameter, soft roll covers and high newspaper machine speed increase starch transfer, while high nip pressure counteracts these drivers. Starch cationization has no affect on pressure-driven penetration, provided the hydrostatic pressure is high and the viscosity of the dispersion is low.

The transferred liquid penetrates into the sheet according to the void space between fibers and pigment particles. During drying, starch attaches to the fibers and pigment, and reinforces the sheet by ‘spot welding’ and bridging between paper constituents. The ultimate location of the starch in the sheet can be affected by chromatographic partitioning behind a front of water that advances into the sheet. This effect will primarily occur in heavyweight paper and board and may lead to a gradient in starch concentration in the sheet from the surface to the interior and a weakening of internal bond at the ultimate location of free water. Starch application to the sheet induces some desizing due to coverage of hydrophobic patches by hydrophilic starch.

Application of surface size to paper carries with it the transfer of a substantial quantity of water. As an example, surface sizing of a 75 g/m2 (50 lb/3300 ft2) sheet (with 1% residual water content) by a 5% starch solution for a coat weight of 1.5 g/m2 (1 lb/3300 ft2/side) will raise the water content of the sheet to 43%. This large quantity of water will weaken the paper. Web breaks at the size press can occur, particularly when the sheet is also weakened as a result of edge cracks or holes.

Surface sizing can induce structural changes in the paper sheet185 due to the interaction of water sorption (which causes a relaxation of internal stresses) and machine direction tension (which increases anisotropy and creates additional stresses). Anisotropy can be lowered by reducing tension on the web during sheet passage through the size press and subsequent dryers, and by raising the moisture content prior to the size press.

When surface-sized paper leaves the size press, it will cling to a roll and has to be pulled off. The separation force due to film splitting depends on the free film thickness, its cohesiveness, and the rheological properties of the surface size, especially its viscoelasticity. Transfer defects, such as ribbing, orange peel, spatter or misting may result. It is important to control the starch viscosity, to use the correct take-off angle and to apply appropriate web tension. Surface-size splashing can occur due to the converging motion of paper sheet and roll surfaces in the pond and fluid rejection at the nip. Best pond stability is obtained at high or low viscosity, while intermediate viscosity is most prone to induce pond instability.

The same basic test liner paper machine used to produce writing and printing paper are also used to form paperboard. However, modern paper machines are limited in their ability to produce a single-layer paper sheet with a grammage above 150 g m−2. There are a number of reasons for this limitation. Primarily, thicker single-layer sheets are more difficult to dewater requiring excessive reductions in machine speed. Furthermore, the increased drainage forces applied to thicker sheets in the forming section would cause greater fines removal from the bottom of the sheet resulting in a rougher surface. The topside of a very thick sheet would also be adversely affected since paper is formed on fourdrinier machines layer by layer from the wire side up, which would allow extra time for the fibers in the top layer to flock and produce a ‘hill and valley’ appearance. The combination of these two effects would produce an unacceptably two-sided product.

Manufacturing multilayered paperboard from separately formed sheets provides a solution to the above-mentioned problems. The forming section of paperboard machines are composed of two, three, or even four forming sections that bring individual sheets together at the wet press. Paperboard machines are for this reason large and complex having heights that are two to three times greater than single-former machines. Any one of the former sections in a multilayer machine can be either a traditional fourdrinier or a modified fourdrinier equipped with a top-wire unit for additional dewatering capacity. The use of different furnishes in each former produces a final sheet that is engineered for specific stiffness and smoothness requirements.

Although initially forming two to three separately formed sheets of paper, a multilayer machine forms a single sheet of paperboard when the individual sheets of paper are combined together in the wet press. The individual single-layered sheets prior to the wet press are ‘vacuum dewatered’ with a typical consistency of 20% (80% moisture) and are simply assemblages of fibers held together by capillary forces exerted by the continuous matrix of water surrounding the fibers. When the sheet continues it progress through the wet press and the dryers, this continuous matrix of water is decreased and the fibers are progressively drawn together through surface tension. Eventually, at the end of the drying process with a final moisture content of 4–8%, the surface tension forces between individual fibers will produce pressures sufficiently high enough to form fiber-to-fiber hydrogen bonds resulting in a mechanically strong sheet. During multilayer forming, a single sheet of paperboard is formed from the individual sheets of paper by merging the water matrices of each sheet into a single, hydraulically connected matrix in the wet press. The net result is that the multilayer sheet continues through the wet press and dryer section forming fiber-to-fiber bonds inside layers and between layers as if they were initially formed together. Theoretically, the fiber-to-fiber bonding between separately formed layers will be identical to fiber-to-fiber bonding within a single layer. Differences in interlayer bonding strength (measured by z-direction strength tests) will be found when the individual sheets are wet pressed at moisture contents lower than what is necessary to form a hydraulically connected matrix. (z-direction strength is the maximum tensile force per unit area which a paper or paperboard can withstand when applied perpendicularly to the plane of the test sample.)

The advantage of manufacturing a multilayer sheet is that key paper properties can be engineered into the paperboard that would not be obtainable by single-layer forming. Special top layers can be incorporated that are white and smooth, therefore, having excellent printing properties. Middle layers can be used that are bulky and thus inherently thicker producing the stiffest possible board. These middle layers can also contain recycle fibers or pulp fibers of lower quality that can be covered or masked by higher quality top and/or bottom layers.
Although starch is usually added at the wet end of the coated board duplex paper machine as a liquid feed directly to the furnish, other systems which place the starch directly on the formed sheet while it is still on the wire of the Fourdrinier machine or on the felt of the cylinder machine may be used. Advantages claimed are improved retention and better distribution of starch throughout the sheet, while permitting the use of low-cost unmodified starch.

In one system, a solution of cooked starch or a dispersion of starch granules is sprayed from nozzles directly onto the wet-web of fibers. By varying concentration, spray pressure, and spray location, a variety of effects can be achieved (24, 25). Three types of spray systems are in use: high-pressure air atomization, high-pressure airless atomization, and low-pressure airless atomization. With high-pressure systems, an electrostatic assist is used to prevent loss owing to misting (26).

In another system, low-density starch foam is applied directly on the wet-web immediately before it enters the wet press. The foam is mechanically broken at the press nip, and the starch is dispersed through the sheet. By controlling foam density, bubble size, and starch concentration, a wide variety of results can be achieved (27). As in the spraying system, very high retentions are possible, and low-cost unmodified starch may be used.

In another system, a thin curtain of liquid is applied to the wet-web (28) for high retention of chemicals, including starches. This system is claimed to be suitable for addition of starch to multi-ply paperboard where it increases ply bond strength.]]> https://uhm.vn/forum/Thread-Tubes-and-pipes-in-technical-and-everyday-use--340304 Thu, 23 Sep 2021 13:09:33 +0700 dnf56sdd8]]> https://uhm.vn/forum/Thread-Tubes-and-pipes-in-technical-and-everyday-use--340304 Tubes and pipes in technical and everyday use
In the beginning was the hollowed-out tree trunk, one of the first capillary tube to be crafted by human hand. With a vast array of models in the plant world to inspire him, Homo sapiens had a much easier job inventing the tube than the wheel for which, by contrast, nature had no example to offer. Bamboo and reed are just two examples of plants with hollow stalks. Nature already knew the value of the tubular form, which combines high stability with the capacity to Transport essential substances for growth, such as water and nutrients, out of the earth.

In technical terms, a tube or pipe is a cylindrical, hard hollow body which usually has a round cross-section but can also be oval, square, rectangular or more complex in profile. It is used on the one hand to convey liquid, gas and solid matter and, on the other, as a construction element. Whatever its purpose, the term covers all sizes and diameters, from the smallest needle pipes right up to wind tunnels. No other profile shape with the same material cross-section has such a high flexural strength, which is what makes the tube so important as a load-bearing element in building.

Tubes for transporting purposes

In the past, people always tried to settle close to water. As the size of the settlements grew, it became increasingly difficult to get the water from the source - the spring, pond, river or lake - to the different dwellings. At first, people used open conduits - initially simple trenches, later stone canals. When the springs and sources were exhausted, aqueducts were used to carry water from the mountains into the towns. Some 300 years A.D., the Romans transported water from the Campagna into their capital and some of their impressive waterways can still be marvelled at in modern-day Europe.

Later, the open canals were covered over and used as closed conduits - and thus the pipeline was born. People were also quick to realize the benefits of closed pipes against open canals for removing waste water. Early pipe materials included wood and stoneware (fired clay), but also easy-to-work metals such as bronze, copper and lead. The first closed pipelines were made around 4,000 years ago of fired clay. The oldest metal pipelines date back to 200 years B.C., first made of bronze and later lead. Lead pipes were cast and chiefly used to Transport water. Copper pipes meanwhile were made from chased copper plate which was rolled and subsequently soldered together.

The advent of an economical method of producing large quantities of cast iron in the 14th century laid the foundation for the manufacture of iron pipes. Gunsmiths and cannon-makers were amongst the first to produce iron pipes. Cast iron pipes were used as early as the 15th century to carry water - some dating back to the 16th century are still in use today. Cast iron pipes also accompanied the development of a public gas supply network, for which compression-proof pipes were a matter of safety and therefore absolutely essential.

As more economical steelmaking methods were developed, an opportunity opened up for this material to be used for pipes. The first were forge-welded out of hoop steel, a method already known to gunsmiths in the Middle Ages. Around 1880, the invention of crossrolling by the Mannesmann brothers also made it possible to produce seamless pipes and tubes. With their thicker walls, seamless pipes offered greater stability at a relatively low weight. Oil-prospectors used such pipes to reach deeper reservoirs and by doing so were able to satisfy the growing demand for mineral oil which accompanied the early days of motorisation. The fact that mineral oil could be transported economically over long distances through a pipeline pushed up the demand for steel pipes even further. Soon, pipelines came to be the biggest market in this area, with demand reaching several million tonnes of welded and seamless pipes every year.

The crucial importance of how a pipe is made for the economic efficiency and environment-friendliness of industrial plant can be illustrated with the contemporary example of seamless boiler pipes with inner ribs. For years the power industry has been aiming to reduce fuel consumption and thereby cut CO2 emissions by stepping up efficiency. This can be done by working with higher operating pressures and temperatures. Consequently, plans have been made to set up new power plant in the first decades of the next century, which will run with pressure levels of up to 350 bar (today's maximum is 300 bar), at operating temperatures of around 700 "C (as opposed to 600 'C) and with efficiency increased from fts current 40% to 50%. Operating parameters of this kind can only be used for suitabie products and materials, of which seamless boiler pipes with inner ribs are one example. On account of their internal geometry, these pipes substantially improve the heat transfer between heating and the vapour phase on the inside of the pipe.

Pipes made of nonferrous metals and plastics Thanks to its good corrosion resistance, copper can be used to make pipes for the chemical industry, refrigeration technology and shipbuilding. Alongside their application for installation purposes, the usually seamless copper pipes are also used in capacitors and heat exchangers. For corrosive materials, low temperatures or stringent demands on the purity of the material carried by the pipe, Aluminium and Aluminium alloys are used in pipe construction. Meanwhile, thanks to its high resistance to many aggressive materials, titanium is well- suited to use in chemical engineering.

Plastics belong to the group of newer pipe materials. With the development of methods for producing plastics on an industrial scale in the 1930s, it also became possible to manufacture plastic pipes economically. By the middle of the 30s, plastics were already being used in Germany to make pressure pipelines. Among the chief advantages of plastics are their high corrosion resistance and a substantial chemical resistance to aggressive media. Moreover, the smooth surfaces mean that plastic pipes are not prone to incrustation, which can have a very detrimental effect on their conveying capacity. Pipes supplying drinking water are mostly made of polyethylene (PE) or polyvinyl chloride (PVC). Like ABS (acrylonftrile-butadiene-styrene copolymer) plastics, these two materials are also used for gas pipelines. Thermoplastic materials - alongside PE and PVC these include PP (polypropylene) and PVDF (polyvinylidenefluoride) - can also be used for industrial pipelines. Beyond these, PB (polybutene) and PE-X (cross- linked polyethylene) are also widespread in pipe-making. Plastic pipes find application in areas such as heating technology, shipbuilding, underwater pipelines (the crossing below a river floor from one bank to the other), irrigating and drainage plant, and well-building.

The right choice of material has a crucial bearing on the economic efficiency and safety of a pipe system. Materials therefore have to be selected according to the demands of each specific application. In steel boiler construction, for example, pipes must be made of steel with high temperature stability plus heat and scaling resistance, while special corrosion resistance is all-important in the chemical and foodstuffs industries. Meanwhile, the mineral-oil processing industry requires heat- proof or press-water-resistant steels for its pipes, gas liquefaction and separation, on the other hand, need materials which have special strength at low temperatures. This broad and highly diversified range of requirements has put a fantastic array of materials to use in pipe- making. Alongside the iron and steel, nonferrous metals and plastics mentioned above, these also take in concrete, clay, porcelain, glass and ceramics.

In addition to liquids and gases, solid matter, broken down, as dust or mixed with water in slurry form, is also pumped through pipelines. Gravel, sand or even iron ore can be conveyed in this manner. Pneumatic transportation of grain, dust and chips through pipes is also a widespread practice. Pneumatic tube conveyors, which similarly work with air, are another important mode of transporting solid matter.

Pipes may be several meters in diameter and pipelines many kilometers in length. At the other end of the scale are conduits with tiny, barely perceptible dimensions. One example of their use is as cannulas in medicine - a collective term referring to instruments with a variety of applications, including infusions, injections and transfusions. Their outer diameter ranges from over 5 millimeters to as little as 0.20 millimeters. Cannulas are made of high-quality grades of stainless steel, brass, silver or nickel silver (an alloy of copper, nickel and zinc, sometimes admixed with traces of lead, iron or tin), but also plastics such as polyethylene, polypropylene or Teflon. Often, different materials are combined with one another to produce the individual components. These tiny tubes must have extremely pronounced elastic properties. They may bend but under no circumstances snap. Their surfaces are often nickel[-plated and always highly polished, sometimes even on the inside. The best-known cannulas are hypodermic needles which, in their most common form as sterile disposable syringes, guarantee aseptic use without costly preparation for reutilisation.

Tubes for construction

No matter where we look in our cities today, we can be sure to see tubular steel constructions. They have become an indispensable element of modern building technology. Once again, we took the idea from nature: in tube-shaped straws, bamboo shoots, quills and bones, Mother Nature demonstrated the successful marriage of beauty and function. Yet these excellent static properties remained unexploited until the advent of welding technology made it possible to connect virtually all dimensions of pipes perfectly and with the necessary interaction of forces for use as construction elements.

As an extremely lightweight building element, steel tube combines high strength with low weight. Steel tubes are used as deck supports in shipbuilding, supports in steel superstructures and binders in building construction. They are used as tubular and lattice masts for overhead and overland transmission lines, for trains and trams, and for lighting. Bridges, railings, observation towers, diving platforms, television towers and roof constructions in halls or sports stadiums are all further examples. Steel tube is also a popular" building element for constructions in temporary use, such as halls, sheds, bridges, spectator stands, podiums and other structures for public events, supporting structures and scaffolding, from the small-scale for house renovation right up to building scaffolds.

In plant engineering, steel tube is used to make ladders, shelves, work tables and subframes for machinery and plant. Steel tube also found its way as a construction element into precision components for machinery and equipment. Shafts and rolls or cylinders in hydraulics and pneumatics are just two examples. Beyond these applications, a great volume of steel tube is used in the cycle industry, camping equipment manufacture, the furniture industry, vehicle and car making and the domestic appliances industry.

Be it on water, over land or in the air, the various modes of Transport would be lost without pipes & tubes. Pipes and tubular construction elements are to be found in ships, planes, trains and motor vehicles. A great variety of pipes and tubular profiles are used in car making, both in connection with the motor and with the chassis and bodywork sections. Most recent developments put them to a far more varied range of uses than before, from air suction pipes and exhaust systems through chassis components right up to side-impact tubes in doors and other safety features. One German car makers new lightweight concept takes as its basic subassembly a three-dimensional frame made up of complex Aluminium extruded sections joined together with the aid of pressure-diecast intersections.

Pipes in everyday use

We come into contact with pipes and tubes on a daily basis. It starts in the morning when we go to clean our teeth and squeeze the toothpaste from this tube, which is nothing other than a tube-shaped flexible container. We write notes with a pen, comprising one or more tubes with a smaller tube - the cartridge or refill - inside it. This is the modern equivalent of the quill, a pointed and split tube used in ancient times as a writing instrument and still used today for Arabic script.

We are surrounded everywhere we go and on a virtually constant basis by seamless pipe ＆ tube, whether at home, on the move or at work. They take the form of lamp stands and furniture elements in chairs or shelves, curtain rails, telescopic aerials on portable and car radios, and rods on umbrellas or sunshades. And when we water the plants or hang out the washing, tubes are our constant companion - on the watering can or the clothes-horse. Pipes Transport electricity, water and gas directly into our homes. Tubes protect visitors to the Duesseldorf Trade Fair Center from the rigours of the Rhineland weather. Pipe constructions are responsible for a pleasant indoor temperature and prevent the hall roofs from falling on our heads. Civil engineers and architects choose special section tube constructions for windows and doors in preference to other solutions. Tubes even have a role to play in our leisure time, providing us with bicycles, training apparatus and sports equipment.

Musical pipes

Musical instrument-making would be unthinkable without welded pipe ＆ tube. The tuba illustrates the connection particularly well: the name of this brass instrument is nothing other than the Latin word for tube. Other brass and pipe instruments also take the tube form. The reed used in a variety of wind instruments such as the clarinet, saxophone, bassoon or oboe is a flexible piece of cane which is fixed into the mouthpiece of the instrument or acts as a mouthpiece itself. Organ pipes also rely on the tube shape to create their sound. They are made of lead and tin, zinc or copper and are still crafted today according to a centuries-old Tradition.

CD stands in the shape of organ pipes make for an original link between two musical words. These CD stands are just under two meters in length, accommodate up to 50 CDs and, if required, can be supplied with interior lighting. Normally out of sight but critically important for good sound quality are the bass-reflex pipes found in loudspeakers. With the proper dimensions in length and diameter, these pipes help to reproduce low-pitched tones without any distortion as a result of unwanted flow noise.

Through squre pipe ＆ tube flows the lifeblood of progress and without them our lives would not be nearly as comfortable. They make everyday life easier, safer, more attractive, more varied and more interesting. More to the point, though, they have become indispensable for our existence, shaping the development of our lives to lasting effect in the past and undoubtedly continuing to do so in the future.]]> Tubes and pipes in technical and everyday use
In the beginning was the hollowed-out tree trunk, one of the first capillary tube to be crafted by human hand. With a vast array of models in the plant world to inspire him, Homo sapiens had a much easier job inventing the tube than the wheel for which, by contrast, nature had no example to offer. Bamboo and reed are just two examples of plants with hollow stalks. Nature already knew the value of the tubular form, which combines high stability with the capacity to Transport essential substances for growth, such as water and nutrients, out of the earth.

In technical terms, a tube or pipe is a cylindrical, hard hollow body which usually has a round cross-section but can also be oval, square, rectangular or more complex in profile. It is used on the one hand to convey liquid, gas and solid matter and, on the other, as a construction element. Whatever its purpose, the term covers all sizes and diameters, from the smallest needle pipes right up to wind tunnels. No other profile shape with the same material cross-section has such a high flexural strength, which is what makes the tube so important as a load-bearing element in building.

Tubes for transporting purposes

In the past, people always tried to settle close to water. As the size of the settlements grew, it became increasingly difficult to get the water from the source - the spring, pond, river or lake - to the different dwellings. At first, people used open conduits - initially simple trenches, later stone canals. When the springs and sources were exhausted, aqueducts were used to carry water from the mountains into the towns. Some 300 years A.D., the Romans transported water from the Campagna into their capital and some of their impressive waterways can still be marvelled at in modern-day Europe.

Later, the open canals were covered over and used as closed conduits - and thus the pipeline was born. People were also quick to realize the benefits of closed pipes against open canals for removing waste water. Early pipe materials included wood and stoneware (fired clay), but also easy-to-work metals such as bronze, copper and lead. The first closed pipelines were made around 4,000 years ago of fired clay. The oldest metal pipelines date back to 200 years B.C., first made of bronze and later lead. Lead pipes were cast and chiefly used to Transport water. Copper pipes meanwhile were made from chased copper plate which was rolled and subsequently soldered together.

The advent of an economical method of producing large quantities of cast iron in the 14th century laid the foundation for the manufacture of iron pipes. Gunsmiths and cannon-makers were amongst the first to produce iron pipes. Cast iron pipes were used as early as the 15th century to carry water - some dating back to the 16th century are still in use today. Cast iron pipes also accompanied the development of a public gas supply network, for which compression-proof pipes were a matter of safety and therefore absolutely essential.

As more economical steelmaking methods were developed, an opportunity opened up for this material to be used for pipes. The first were forge-welded out of hoop steel, a method already known to gunsmiths in the Middle Ages. Around 1880, the invention of crossrolling by the Mannesmann brothers also made it possible to produce seamless pipes and tubes. With their thicker walls, seamless pipes offered greater stability at a relatively low weight. Oil-prospectors used such pipes to reach deeper reservoirs and by doing so were able to satisfy the growing demand for mineral oil which accompanied the early days of motorisation. The fact that mineral oil could be transported economically over long distances through a pipeline pushed up the demand for steel pipes even further. Soon, pipelines came to be the biggest market in this area, with demand reaching several million tonnes of welded and seamless pipes every year.

The crucial importance of how a pipe is made for the economic efficiency and environment-friendliness of industrial plant can be illustrated with the contemporary example of seamless boiler pipes with inner ribs. For years the power industry has been aiming to reduce fuel consumption and thereby cut CO2 emissions by stepping up efficiency. This can be done by working with higher operating pressures and temperatures. Consequently, plans have been made to set up new power plant in the first decades of the next century, which will run with pressure levels of up to 350 bar (today's maximum is 300 bar), at operating temperatures of around 700 "C (as opposed to 600 'C) and with efficiency increased from fts current 40% to 50%. Operating parameters of this kind can only be used for suitabie products and materials, of which seamless boiler pipes with inner ribs are one example. On account of their internal geometry, these pipes substantially improve the heat transfer between heating and the vapour phase on the inside of the pipe.

Pipes made of nonferrous metals and plastics Thanks to its good corrosion resistance, copper can be used to make pipes for the chemical industry, refrigeration technology and shipbuilding. Alongside their application for installation purposes, the usually seamless copper pipes are also used in capacitors and heat exchangers. For corrosive materials, low temperatures or stringent demands on the purity of the material carried by the pipe, Aluminium and Aluminium alloys are used in pipe construction. Meanwhile, thanks to its high resistance to many aggressive materials, titanium is well- suited to use in chemical engineering.

Plastics belong to the group of newer pipe materials. With the development of methods for producing plastics on an industrial scale in the 1930s, it also became possible to manufacture plastic pipes economically. By the middle of the 30s, plastics were already being used in Germany to make pressure pipelines. Among the chief advantages of plastics are their high corrosion resistance and a substantial chemical resistance to aggressive media. Moreover, the smooth surfaces mean that plastic pipes are not prone to incrustation, which can have a very detrimental effect on their conveying capacity. Pipes supplying drinking water are mostly made of polyethylene (PE) or polyvinyl chloride (PVC). Like ABS (acrylonftrile-butadiene-styrene copolymer) plastics, these two materials are also used for gas pipelines. Thermoplastic materials - alongside PE and PVC these include PP (polypropylene) and PVDF (polyvinylidenefluoride) - can also be used for industrial pipelines. Beyond these, PB (polybutene) and PE-X (cross- linked polyethylene) are also widespread in pipe-making. Plastic pipes find application in areas such as heating technology, shipbuilding, underwater pipelines (the crossing below a river floor from one bank to the other), irrigating and drainage plant, and well-building.

The right choice of material has a crucial bearing on the economic efficiency and safety of a pipe system. Materials therefore have to be selected according to the demands of each specific application. In steel boiler construction, for example, pipes must be made of steel with high temperature stability plus heat and scaling resistance, while special corrosion resistance is all-important in the chemical and foodstuffs industries. Meanwhile, the mineral-oil processing industry requires heat- proof or press-water-resistant steels for its pipes, gas liquefaction and separation, on the other hand, need materials which have special strength at low temperatures. This broad and highly diversified range of requirements has put a fantastic array of materials to use in pipe- making. Alongside the iron and steel, nonferrous metals and plastics mentioned above, these also take in concrete, clay, porcelain, glass and ceramics.

In addition to liquids and gases, solid matter, broken down, as dust or mixed with water in slurry form, is also pumped through pipelines. Gravel, sand or even iron ore can be conveyed in this manner. Pneumatic transportation of grain, dust and chips through pipes is also a widespread practice. Pneumatic tube conveyors, which similarly work with air, are another important mode of transporting solid matter.

Pipes may be several meters in diameter and pipelines many kilometers in length. At the other end of the scale are conduits with tiny, barely perceptible dimensions. One example of their use is as cannulas in medicine - a collective term referring to instruments with a variety of applications, including infusions, injections and transfusions. Their outer diameter ranges from over 5 millimeters to as little as 0.20 millimeters. Cannulas are made of high-quality grades of stainless steel, brass, silver or nickel silver (an alloy of copper, nickel and zinc, sometimes admixed with traces of lead, iron or tin), but also plastics such as polyethylene, polypropylene or Teflon. Often, different materials are combined with one another to produce the individual components. These tiny tubes must have extremely pronounced elastic properties. They may bend but under no circumstances snap. Their surfaces are often nickel[-plated and always highly polished, sometimes even on the inside. The best-known cannulas are hypodermic needles which, in their most common form as sterile disposable syringes, guarantee aseptic use without costly preparation for reutilisation.

Tubes for construction

No matter where we look in our cities today, we can be sure to see tubular steel constructions. They have become an indispensable element of modern building technology. Once again, we took the idea from nature: in tube-shaped straws, bamboo shoots, quills and bones, Mother Nature demonstrated the successful marriage of beauty and function. Yet these excellent static properties remained unexploited until the advent of welding technology made it possible to connect virtually all dimensions of pipes perfectly and with the necessary interaction of forces for use as construction elements.

As an extremely lightweight building element, steel tube combines high strength with low weight. Steel tubes are used as deck supports in shipbuilding, supports in steel superstructures and binders in building construction. They are used as tubular and lattice masts for overhead and overland transmission lines, for trains and trams, and for lighting. Bridges, railings, observation towers, diving platforms, television towers and roof constructions in halls or sports stadiums are all further examples. Steel tube is also a popular" building element for constructions in temporary use, such as halls, sheds, bridges, spectator stands, podiums and other structures for public events, supporting structures and scaffolding, from the small-scale for house renovation right up to building scaffolds.

In plant engineering, steel tube is used to make ladders, shelves, work tables and subframes for machinery and plant. Steel tube also found its way as a construction element into precision components for machinery and equipment. Shafts and rolls or cylinders in hydraulics and pneumatics are just two examples. Beyond these applications, a great volume of steel tube is used in the cycle industry, camping equipment manufacture, the furniture industry, vehicle and car making and the domestic appliances industry.

Be it on water, over land or in the air, the various modes of Transport would be lost without pipes & tubes. Pipes and tubular construction elements are to be found in ships, planes, trains and motor vehicles. A great variety of pipes and tubular profiles are used in car making, both in connection with the motor and with the chassis and bodywork sections. Most recent developments put them to a far more varied range of uses than before, from air suction pipes and exhaust systems through chassis components right up to side-impact tubes in doors and other safety features. One German car makers new lightweight concept takes as its basic subassembly a three-dimensional frame made up of complex Aluminium extruded sections joined together with the aid of pressure-diecast intersections.

Pipes in everyday use

We come into contact with pipes and tubes on a daily basis. It starts in the morning when we go to clean our teeth and squeeze the toothpaste from this tube, which is nothing other than a tube-shaped flexible container. We write notes with a pen, comprising one or more tubes with a smaller tube - the cartridge or refill - inside it. This is the modern equivalent of the quill, a pointed and split tube used in ancient times as a writing instrument and still used today for Arabic script.

We are surrounded everywhere we go and on a virtually constant basis by seamless pipe ＆ tube, whether at home, on the move or at work. They take the form of lamp stands and furniture elements in chairs or shelves, curtain rails, telescopic aerials on portable and car radios, and rods on umbrellas or sunshades. And when we water the plants or hang out the washing, tubes are our constant companion - on the watering can or the clothes-horse. Pipes Transport electricity, water and gas directly into our homes. Tubes protect visitors to the Duesseldorf Trade Fair Center from the rigours of the Rhineland weather. Pipe constructions are responsible for a pleasant indoor temperature and prevent the hall roofs from falling on our heads. Civil engineers and architects choose special section tube constructions for windows and doors in preference to other solutions. Tubes even have a role to play in our leisure time, providing us with bicycles, training apparatus and sports equipment.

Musical pipes

Musical instrument-making would be unthinkable without welded pipe ＆ tube. The tuba illustrates the connection particularly well: the name of this brass instrument is nothing other than the Latin word for tube. Other brass and pipe instruments also take the tube form. The reed used in a variety of wind instruments such as the clarinet, saxophone, bassoon or oboe is a flexible piece of cane which is fixed into the mouthpiece of the instrument or acts as a mouthpiece itself. Organ pipes also rely on the tube shape to create their sound. They are made of lead and tin, zinc or copper and are still crafted today according to a centuries-old Tradition.

CD stands in the shape of organ pipes make for an original link between two musical words. These CD stands are just under two meters in length, accommodate up to 50 CDs and, if required, can be supplied with interior lighting. Normally out of sight but critically important for good sound quality are the bass-reflex pipes found in loudspeakers. With the proper dimensions in length and diameter, these pipes help to reproduce low-pitched tones without any distortion as a result of unwanted flow noise.

Through squre pipe ＆ tube flows the lifeblood of progress and without them our lives would not be nearly as comfortable. They make everyday life easier, safer, more attractive, more varied and more interesting. More to the point, though, they have become indispensable for our existence, shaping the development of our lives to lasting effect in the past and undoubtedly continuing to do so in the future.]]>