Specialty fibers

Cydohexanedimethanol can be the comonomer. TerephthaHc acid can also be the diacid in specialty nylons (see Polyamides). Specialty fibers, including certain high modulus aramid fibers, are made from terephthaHc acid—dimethyl terephthalate derivatives. 

Major uses of aniline include -methylene diphenyl diisocyanate (MDI) (75%) and rubber chemicals (15%) production. It is also used to a smaller extent in herbicides (4%), dyes and pigments (3%), and specialty fibers (2%). 

These specialty fibers and whiskers exhibit some of the highest tensile strengths recorded (Tables 14.1 and 14.2) they are employed in applications where lightweight and high strength... 

Regenerated proteins from casein (lanital), peanuts (ardil), soybeans (aralac), and zine (vicara) are used as specialty fibers. Regenerated and modified cellulose products, including acetate, are still widely used today and the production of fibers is similar to that described above for synthetic fiber production. Most regenerated cellulose (rayon) is produced by the viscose process where an aqueous solution of the sodium salt of cellulose xanthate is precipitated in an acid bath. The relatively weak fibers produced by this wet spinning process are stretched to produce strong rayon. 

Various types of optical fibers are used for specific applications. For example, multimode fibers are used primarily in enterprise systems buildings, offices, campuses. Special single-mode transmission fibers exist for submarine applications, and for metropolitan and long-haul terrestrial applications. And in addition to these transmission fibers, there are various specialty fibers for performing dispersion compensation (dispersion compensating fiber), optical amplification (erbium-doped fiber), and other special functions. 

Aniline is used in the rubber industry for the manufacture of various vulcanization accelerators and age resistors. Aniline is also used in the production of herbicides, dyes and pigments, and specialty fibers. 

Aniline is consumed as a raw material in the manufacture of a number of chemicals /7,/7-methylene diphenyl diisocyanate (MDI), 65 percent rubber-processing chemicals, 15 percent herbicides, 5 percent dyes and pigments, 4 percent specialty fibers, 2 percent. Other uses are in pharmaceuticals and photo chemicals. Principal growth is occurring from demand for MDI and the small, rapidly growing specialty fibers. 

Elastane. The DuPont Company commercialized the first manufactured elastic fiber, Lycra, in 1958. Originally categorized as a span-dex fiber, the name elastane has become more common around the world. This specialty fiber is described as a segmented polyurethane that contains hard and soft segments their ratio determines the amount of stretch built into the fiber. Elastane fibers are formed by dry-spinning or solvent-spinning. The continuous filaments can be coalesced multifilaments or monofilaments, depending on the manufacturer. 

Polyvinyl Chloride. (Table 15.5) this is the most versatile of the commercial thermoplastic polymers. It is used mainly for rigid and flexible plastics, for rubberlike products, for coatings on steel, cloth, and paper, and in smaller amounts for specialty fibers. It is processed mainly by extrusion and calendering, and in smaller amounts by injection, compression, and... 

Other aniline uses and the percent of worldwide aniline production that goes into these uses are rubber-processing chemicals (9%), dyes and pigments (2%), agricultural chemicals (3%), specialty fibers (1%), and miscellaneous, such as explosives, epoxy curing agents, and pharmaceuticals (1%).138,255... 

Chemicals Manufacturing Functional Plastics PVC Piping Caustic Soda Specialty Fibers Electronics Products Expandable Plastic Products Food Products... 

In addition to wool and silk, a number of specialty fibers are also obtained from animals. In most cases, animal fibers are similar to each other. They grow in two principal coats the shiny and stiff outer coat or hair and the undergrowth or fur. Hair forms a protective shield around the animal s body against the elements fur is closer to the skin and consists of shorter fibers than the hair that acts as insulation against heat or cold. 

Fabrics containing specialty fibers are expensive because of the difficulties in obtaining the fibers, and the amount of processing required to prepare the fibers for use. Unlimited combinations of specialty fibers with wool are possible. Specialty fibers may be used to add softness or luster to fabrics. They also enhance the insulating properties of blended fabrics. 

Aromatic polyamides or aramids. The best known in the specialty fiber market are Nomex (poly-m-phenyleneisophthalamide) and Kevlar (poly-p-phenyleneterephthala-mide). 

Textile definitions most generally accepted for reference in the United States are those standardized by the American Society for Testing Materials and published in ASTM Standards on Textile Materials (W, 25). The Federal Trade Commission has also established definitions for use in enforcing its Trade Practice Rulings 20). These may differ from the ASTM definitions—for example, the ASTM restricts its definition of wool to the fiber from the fleece of the sheep, whereas the Federal Trade Commission defines it as the fiber from the fleece of the sheep or lamb or hair of the Angora or Cashmere goat (and may include the so-called specialty fibers from the hair of the camel, alpaca, llama, and vicuna). ... 

Wool. American Wool Handbook. A Practical Text and Reference Book for the Entire Wool Industry well describes this useful volume by Werner Von Bergen and Herbert R. Mauersberger. The second edition, published in 1948, includes chapters on historical and economic background, sheep breeds and raising, specialty fibers, physical and chemical properties of wool, chemical and mechanical processing, testing, and bibliographies (115). 

Fibers a diversified mix of specialty fibers for protective apparel, sportswear, for high-strength composites, carpeting, and industrial applications to serve consumer and industrial markets... 

We embarked on a large program five years ago to demonstrate that we can use our technical innovation power, coupled with a partner s capability in engineering enzymes, to make bulk chemicals and fibers cost effectively. Our goal was to produce a specialty fiber we call Sorona (Figure 6), which incorporates the attractive properties of nylon, Dacron and Lycra, resulting in superior softness, vibrant color, UV and chlorine resistance, and stain resistance coupled with stretch and recovery. Market test development shows that consumers find this combination of functionalities very attractive. 

Economy, J. "New and Specialty Fibers" Wiley New York, 1976. Eisenraan, G. "Membranes" Dekker New York, 1975. 

Specialty Fiber Optic Systems for Mobile Platforms and Plastic Optical Fibers, Eds., L. Figueroa, M. Kitazawa, N.E. Lewis, R.E. Steele and D. Varshneya, Proceedings of the SPIE, Volume 1799, Bellingham, WA, USA, 1993. 

Spigulis, J., Pfafrods, D., 1997. Clinical potential of the side-glowing optical fibers. Proc. SPIE 2977, Specialty Fiber Optics for Biomedical and Industrial Applications. Available at http // proceedings. spiedigitallibrary.org/proceeding.aspx articldd=1027546 (accessed 30.09.14.). 

Many specialty fibers have been developed over the years for special end- uses. An example of excellent industrial accomplishment is the development of TRIAD fiber shown in Figure 2.19. Used in FRAM automotive air filter, the TRIAD fiber helps trap dirt inside its microscopic channels that in turn trap more dirt without increasing the air flow restriction. Another example is the preparation of a conductive fiber using the bicomponent fiber technology with a built-in conductive fiber. Figure 2.42, Item 29, shows a fiber cross-section where the dark-colored portion of the fiber is the conductive portion. 

The properties of cuprammonium rayon are sufficiently different from those of viscose rayon that today it is produced as a specialty fiber for several applications. Apart from its use as a substitute for silk in scarves, ties, fine dresses, and linings, the use of hollow cuprammonium fibers for hemodialysis in artificial kidneys has become important. 

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