Non Cellulose Polymer Fibers

This group of fibers is distinguished by being synthesized or created from various elements into large molecules which are called linear polymers because they are connected in link like fashion. The molecules of each particular compound are arranged in parallel lines or rows in the fiber, similar to the way fibers are arranged in yarn. This arrangement of molecules is called molecular orientation. The properties of such fibers are dependent upon their chemical compositions and kinds of molecular orientation. There are several distinct varieties of synthetic long-chain polymers. Fiber definitions that follow were set forth by the FTC in accordance with the Textile Fiber Products Identification Act.

Nylon

Nylon is a manufactured fiber in which the fiber-forming substance is any long-chain synthetic polyamide in which less than 85 percent of the amide linkages are attached directly to two aromatic rings. The elements carbon, oxygen, nitrogen, and hydrogen are combined by chemical processes into compounds which react to form long-chain molecules, known chemically as polyamides, and are then formed into fibers. There are several forms of nylon; each depends upon the particular chemical synthesis. They are nylon 4; 6; 6,6; 6,10; 6,12; 8; 10; and 11. There are different types under various trademarks (see Table 20-1) within each of these forms of nylon. Nylon is thermoplastic, resilient, elastic, and very strong. It is used for a wide variety of apparel, home furnishings, and industrial products.

Aramid

Aramid is a manufactured fiber in which the fiber-forming substance is a long-chain synthetic polyamide in which at least 85 percent of the amide linkages are attached directly to two aromatic rings. This definition indicates a relationship to nylon; the difference is in the percentage of linkage of the carbon, oxygen, nitrogen, and  hydrogen amide groups directly attached to the two aromatic rings. Aramid fibers are produced in different forms, each dependent upon the particular percentage of linkage or chemical synthesis. Aramid fibers are extremely strong and flame-resistant. They are used for certain consumer products and principally for industrial purposes. Aramid fibers are manufactured under two trademarks: Nomex and Kevlar.

Polyester

Polyester is a manufactured fiber in which the fiber-forming substance is any long-chain synthetic polymer composed of at least 85 percent by weight of an ester of a substituted aromatic carboxylic acid, including but not restricted to substituted terephthalate units and para-substituted hydroxyl-benzoate units. In producing such fibers, the basic elements of carbon, oxygen, and hydrogen are polymerized. Variations are possible in the methods of production, in the combination of ingredients, and in the ultimate molecular structures of the fiber-forming substance. Polyester fibers are produced by several manufacturers under their respective trademarks. Polyester fibers are thermoplastic. They have good strength and are hydrogen, that is, they do not absorb water well. Polyester is used for a wide variety of apparel, home furnishings, and industrial fabrics.

Acrylic

Acrylic is a manufactured fiber in which the fiber-forming substance is any long-chain synthetic polymer composed of at least 85 percent by weight of acrylonitrile units. By complicated processes, ca bon, hydrogen, and nitrogen, the basic elements, are usually synthesized with small amounts of other chemicals (to improve the fiber’s ability to absorb dyes) into large polymer combinations. Variations are possible in the methods of production, in the combination of ingredients, and in the ultimate molecular structures of the fiber-forming substance. Varieties or acrylics are identified by such trademarks as Acrilan, Creslan, Orlon, and Zefran. Each of these has its own modifications, which have special properties and are designed to suit particular purposes. In general, acrylic fibers have a soft, warm hand resembling wool or cashmere. They are resilient and shape-retentive and are used for apparel and home furnishings.