Acrylic fiber is a synthetic fiber made from polymer (polyacrylonitrile) with an average molecular weight of ~ 100,000, about 1900 units of monomer. Acrylic fiber is very useful in our daily lives. For fibers called "acrylics" in the US, the polymer must contain at least 85% acrylonitrile monomer. Typical comonomers are vinyl acetate or methyl acrylate. DuPont created the first acrylic fiber in 1941 and trademarked them under the name Orlon. It was first developed in the mid-1940s but was not produced in large numbers until the 1950s. Strong and warm, acrylic fiber is often used for sweaters and sportswear and as a coating for boots and gloves, as well as fabrics and rugs. These are made as filaments, then cut into short staple lengths similar to woolen feathers, and spun into yarn.
Modacrylic is a modified acrylic fiber containing at least 35% and at most 85% acrylonitrile monomers. The vinyl chloride, vinyl chloride or vinyl bromide comonomer used in the modacrylic provides the fiber fire retardant properties. End-uses modacrylic including imitation fur, wigs, hair extensions and protective clothing.
Video Acrylic fiber
Production
This polymer is formed by the polymerization of free radicals in aqueous suspensions. The fiber is produced by dissolving the polymer in a solvent such as N, N-dimethylformamide (DMF) or dilute sodium thiocyanate, metering through a multi-hole spinnerette and coagulating filaments produced in aqueous solutions of the same solvent (wet spinning). ) or vaporize the solvent in a heated inert gas stream (dry spinning). Washing, stretching, drying and disconnecting process. Acrylic fibers are produced in various deniers, typically 0.9 to 15, as cut staples or as 500,000 to 1 million filament tows. The end uses include sweaters, hats, hand knitting yarns, socks, carpets, awnings, boat coverings, and upholstery; fiber is also used as a precursor of "PAN" for carbon fiber. Acrylic fiber production is concentrated in the Far East, Turkey, India, Mexico and South America, although a number of European producers are still in operation, including Dralon and Fisipe. US producers have ended production (except for special uses such as friction materials, gaskets, specialty paper, conductive and plastering), although acrylic slabs and staples are still spun into yarn in the US. Former US acrylic includes Acrilan (Monsanto), and Creslan (American Cyanamid). Other brand names still in use include Dralon (Dralon GmbH) and Drytex (Sudamericana de Fibras, SA). In late 1950 Courtalds Ltd began investigating the production of acrylic fibers then called "courtelle" by the solvent polymerization process. Methyl acrylate (6%) and acrylonitrile are polymerized in 50% sodium thiocyanate solution to produce a drug ready to spin into water to produce a "handle" fiber in various denier levels. The sodium thiocyanate solution is reconstituted and reused. The reaction is a continuous process with about 5% reactants being recycled. This recycling process results in a buildup of pollutants in the process as well as recycling of solvents. Much of the research in Chemical engineering laboratories at Lockhurst Lane, Coventry, and at a pre production pilot plant at Little Heath overcame the recycling problem and resulted in a process of becoming a commercial success at a new production plant in Grimsby.
Maps Acrylic fiber
Textile use
Acrylic is light, soft, and warm, with shades like wool. It can also be made to mimic other fibers, such as cotton when spun on short staple equipment. Some acrylics are extruded in colored or pigmented forms; others extruded in "ecru", otherwise known as "natural," "raw white," or "not littered." The pigmented fibers have the highest lightfastness. The fiber is very tough compared to synthetic and other natural fibers. Some acrylic is used in clothing as a cheaper alternative to cashmere, because of the same feeling of material. Some acrylic fabrics may be feathered or pills easily, although there are low pilling variants. Acrylic takes a good, washable, and generally hypoallergenic color. The end uses include socks, hats, gloves, scarves, sweaters, home furnishing fabrics, and awnings. Acrylic can also be used to make fake fur and make many different knitwear.
Because acrylic is a synthetic fiber, moth clot larvae can not digest it. However, acrylic fibers mixed with wool or dirt can be eaten as a consequence of having mixed fibers.
Acrylic is a "hard worker" craft fiber for knit or crochet craftsmen; acrylic yarns can be considered "cheap" because they are usually cheaper than their natural fiber counterparts, and therefore do not have some of their properties, including tenderness and tendency to be felt. The fiber requires heat to "relax" or set the shape of the garment, and not warm when wet as an alternative such as wool. Some hand-kniters also complain that the fibers "creak" when knitted, or that it is painful to be knitted for lack of "giving" or stretching the thread. On the other hand, the machine can be washed and very fast color. This makes it useful in certain items, such as clothes for babies, which require constant washing. However it is much more flammable than its natural fiber counterparts, so caution should be used when making items for babies and children.
Worries
- A team at Plymouth University in England spent 12 months analyzing what happens when a number of synthetic materials are washed at different temperatures in a domestic washing machine, using different combinations of detergents, to measure the microfibres warehouse. They found that acrylic is responsible for releasing nearly 730,000 small (microplastic) synthetic particles per wash, five times more than polyester-cotton blend fabrics, and almost 1.5 times more than polyester.
- Ecological Mark Browne finds something scientifically important after months of researching sediments along coastlines around the world. He saw fiber waste unpredictable by others. They are small, synthetic, and across the coastline, with the greatest concentrations near the waste stream. Of the man-made materials found on the coastline, 85% are microfiber and match material types (such as nylon and acrylic) used in clothing.
See also
- List of fabrics
References
Source of the article : Wikipedia
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