Nylon fibers production

Includes 1,243 thousand tonnes in nylon fiber production, for 1994 and 2003, respectively. 

World production is summarized by fiber type in Table 12.42 [690]. The data show a decline in acrylic and nylon fiber production and a steadily increasing produetion of polyester fiber. Polyester, a mainstay of the low-cost and easy-care markets, has grown considerably in the developing countries. Recent advances in the recycle of polyester has put more cost pressure on markets where polyester has been excluded because of deficiencies in properties. An example is the carpet face yarn market where polyester has suffered from its lack of resiliency and tendency for matting. New, durable constructions are possible with lower cost polyester supplies. Olefin production, while relatively low compared to the others, is also growing steadily. 

Fig. 1. (a) World production of nylon fiber (11) (b) world consumption of nylon resins (12). 

The 1997 U.S. production of nylon fibers was approximately 2.9 billion pounds. 

Nylon blends, dyeing, 9 204 Nylon block copolymer, 19 762 Nylon carpet fibers, stain-resistant, 19 764 Nylon-clay nanocomposites, 11 313-314 Nylon extrusion, temperatures for, 19 789t Nylon feed yarns, spin-oriented, 19 752 Nylon fiber(s), 24 61 production of, 19 740 world production of, 19 7654 Nylon fiber surfaces, grafting of polymers on, 19 763-764... 

PTT fibers and yams have bulk, resiliency, stretch-recovery, softness, hand and drape, properties which are similar to those of nylons and much better than those of PET. Such materials are inherently resistant to most stains which are acidic in nature because they not have dye sites. They also have a lower static propensity than nylons. PTT fibers are dyed with disperse dyes but at a lower temperature than PET because of the polymer s lower Tt. The combinations of these properties are attractive to carpet and textile manufacturers in some applications where PTT could replace nylon or PET. PTT also offers the potential of creating new fiber products by using the unique combinations of these properties not found in either nylon or PET alone. 

The first Nylon 66 fiber production facility came on stream in 1939. The first nylon stockings were marketed in May 1940— just in time for G.I. s to take them to Europe in World War II. 

DuPont continued their leadership role in synthetic fibers by commercializing acrylic fibers (Orion) in 1950. They did a repeat performance in 1-953 with a polyester called Dacron. The big four fibers—Nylon 6, Nylon 66, acrylics, and polyester—now account for most of the synthetic production and about half of the fiber production of all kinds, including cotton, silk, and wool. 

However, synthetic fibers (cellulosic and noncellulosic) increased much more rapidly in importance, with cellulosics booming between World Wars I and II and noncellulosics dominating after World War II, while all that time cotton showed only a steady pace in comparison. The more recent competition between the various fibers in the United States is given in Fig. 17.1. Nylon was originally the most important synthetic (1950-1971) but polyester now leads the market (1971-present). For a few years (1970-1980) acrylics were third in production, but since 1980 polyolefins have been rapidly increasing. Polyolefins are now second only to polyester in synthetic fiber production. Cotton, being an agricultural crop, certainly demonstrates its variable production with factors such as weather and the economy. It is an up-and-down industry much more so than the synthetics. 

Microfibers are also made by simple extrusion through a spinneret with a smaller hole than normally employed for fiber production. The third method involves spinning a bi-component fiber and using a solution to split the fiber into smaller pieces. Initially, bi-component fibers in the range of 2-4 denier are spun and then split into microfibers. If a 32-segment pie of nylon-polyester fiber is used, the final fineness is on the order of 0.1 denier. Brushing and other techniques can be used to enhance the effects. Hollow fibers are also being used... 

Approximately 3.9 x 106 t of nylon fiber is produced worldwide nylon-6,6 and nylon-6 account for about 98% of the total production. Nylon fibers are used for carpets, tire cord, cordage, soft-sided luggage, automotive air bags, parachutes, apparel, swimwear, and sheer hosiery. The advantages of nylon fibers over other synthetic fibers are high strength, durability, resilience, ease of dyeability, and low specific gravity. 

Tn the last decades many attempts have been made to obtain attractive - materials by intimate mixing of two polymers with opposite or complementary properties. For example, the impact resistance of brittle polystyrene is increased by mixing with a rubber the wettability of polyacrylonitrile fiber is increased by mixing with hydrophilic saponified cellulose acetate, and the inconvenient flat-spotting of nylon-reinforced tires is suppressed by mixing stiffer polyester fibrils into the nylon fibers. In practically all cases these products acquire their final shape via the liquid state. Thus, the viscous properties of these liquid mixtures are important. 

Pyrolysis produces three principal products - pyrolytic gas, oil, and char. Char is a fine particulate composed of carbon black, ash, and other inorganic materials, such as zinc oxide, carbonates, and silicates. Other by-products of pyrolysis may include steel (from steel-belted radial tires), rayon, cotton, or nylon fibers from tire cords, depending on the type of tire used. 

CNC ARIDRY C is a water repellent designed primarily as semi-durable to durable water repellent for most hydrophobic fibers, especially nylon. This product is also an excellent extender for fluorochemical finishes. 

Table 21.1 gives production data for some of the commercially important condensation polymers [5, 6]. It is evident that the phenolics and the saturated polyesters and nylons destined for fiber production are all major players with American production levels for each of these of well over a million metric tonnes per year by 1994. Also evident in the American context is the strong rate of growth in the listed polymers. 

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