Synthetic fiber garments

Heavy-duty wiping materials and some disposable garments are made from nonwoven ceUulose mats which are reinforced with a synthetic fiber, eg, nylon scrim network the spacing of the synthetic threads is 0.5—1.0 cm (108). 

Since fungi thrive in warm, moist environments, the practitioner should encourage patients to wear loose-fitting clothing and socks, preferably garments made of cotton or other fabrics that wick moisture away from the body. Avoid clothing made with synthetic fibers or wool. 

All personnel handling explosives are recommended not to wear garments made of synthetic fibers. 

Until the mid 20th century only natural textile fibers were generally available, and most garments were made of either wool or cotton. From the 1940s onward natural fibers were more commonly partly replaced by synthetic fibers used either on their own or in mixed natural and synthetic yarn. By the late 20th century natural fiber use had dropped worldwide to approximately 35%. Despite this, cotton remains the most widely used textile fiber (Miller 1992). The second half of the 20th century saw a massive expansion not only in the use of synthetic fibers but also in natural-synthetic fiber mixtures. 

Adipic acid [HOjC E COjH], the main product of cyclohexane, is reacted with hexamethylene diamine to produce nylon-6,6, a very strong synthetic fiber. Most carpets are made of nylon, as are many silklike garments, some kinds of rope, and many injection-molded articles. 

PLA fibers are environment-friendly material and the demand for PLA fibers as a substitute for the present synthetic fibers has been growing greatly in recent years. Furthermore, high water vapor transmission rate of PLA makes it a good candidate for fabricating fibers used in garments [e.g., shirts, dresses, underwear, shoes, etc.] to improve their "breathability. While PLA fibers are not as wettable as cotton, they exhibit much greater water vapor transmission than aromatic polyesters or nylon fibers. 

Microcapsules can be applied on any fabric (woven, knitted, nonwoven or garments). The substrate may be wool, silk, cotton, flax, or synthetic fibers such as polyamide or polyester, or mixtures. Most of the microcapsules can be appHed using conventional finishing techniques without altering the feel and color of colored fabrics or printed patterns. Microcapsules can also be applied during the rinse cycle of a washing machine. 

In certain cases, identifying the specific garment or textile product and the allergen it contains will be an important undertaking. The fiber content of the fabric will narrow the possible dyes, as certain dyes are used to color certain fibers. Cotton, rayon, and linen fabrics are dyed with direct, fiber-reactive, mordant, azoic, sulfur, and vat dyes. Wool fabrics are dyed with acid, mordant, and fiber-reactive dyes. Polyester fabrics are dyed with disperse dyes unless the polyester is modified to accept basic dyes. Nylon fabrics are colored with acid and disperse dyes unless modified to accept basic dyes. Acrylic fabrics are dyed with basic and disperse dyes. Acetate fabrics are dyed with disperse dyes. Other synthetic fibers are dyed with disperse dyes. 

Dyes used to color fabrics are the most likely textile chemicals to cause skin problems, and among the dyes it is the disperse dyes with azo and anthraquinone chemistries used to color polyester and other synthetic fibers that are the most troublesome. The pattern of distribution of lesions on the patient s body may serve as a clue that dyes are involved. The distribution of lesions will lie where the garment directly contacts the skin and at points were friction and moisture add to the transfer of the dyes from the fabric to the skin. There is no compound or single mixture of compounds that is a reliable indicator of textile-dye allergy. However, PPD and other para-containing compounds are used to indicate azo-dye sensitivity. 

The group of polymers called nylons was first produced in 1939 as a material for women s hose and other garments and was the world s first totally synthetic fiber. Nylon hose were an instant hit with the buying public 800,000 pairs were sold on May 15, 1940, the first day they were on the market With the onset of World War II and the involvement of the United States, by 1941, nylon was taken off the domestic market because it was found to be the best available material for military parachutes. 

The development of nylon. Dacron, and a host of other synthetic fibers revolutionized many industries, including clothing, carpeting, and the like. One of the most remarkable members of this family is Lycra, the trademark ascribed by DuPont to a family of fibers known generically as spandex. In the 1960s, Lycra was introduced as a great improvement over natural rubber in "ladies foundation garments". 

Next to PLM, IR spectroscopy (principally, micro-IR) makes up the most important family of techniques in fiber analysis. As with PLM, IR spectroscopy is minimally destructive or nondestruchve and is useful on even the smallest fiber fragments. Microspectrophotometry (MSP) probes the chemical identification of the synthetic fiber, colorants, and other treatments. MSP is indispensable in the comparative analysis of questioned and known fibers, the central task of most forensic fiber analysis cases. The caveat is that such comparisons require knowledge of typical inter- and intrasample variation. Consider, for example, a pair of blue jeans typically, fibers from along the seams and hems are worn compared with fibers to other portions of the garment. Also, the source from which a sample is obtained will clearly affect any visible spectra and color analysis. Along a single fiber, characteristics of a dye or colorant will vary as well. Such inherent variations must be factored into any conclusions drawn from a comparative analysis, be it of dye or chemical composition. 

The versatility of rayons, coupled with their lower price, makes them suitable for many textile applications. Rayon is used in clothing and home furnishings. Disposable nonwoven garments and products of rayon have been introduced to the consumer in recent years. The stronger rayons have been used in tire cord for several decades but have lost a significant portion of this important market in recent years. Rayon has been used more and more in blends with synthetic fibers, since rayon undergoes less degradation than cotton with durable press and wash-and-wear finishes. 

Fibers and garments recovered as evidence may have been exposed to sunlight or water or buried for extended periods of time. Despite the significance of textile fibers as trace evidence, there have been few studies of the effects of the environment in which fibers are found on the procedures used to identify and compare them. It was the object of this study to expose various synthetic fibers to a soil environment and determine the effects of biodeterioration in such an environment on the analytical methods used to identify and compare synthetic fibers in the forensic science laboratory. 

William Henry Perkin, an 18-year-old working in the back room and outdoor shed of his London home, had discovered in black coal tar a beautiful purple dye that would change the world. For the first time in history, color could be democratized. William Henry Perkin and his purple, later known as mauve, rescued the poor and middle classes from their age-old austerity of hues. Natural dyes were expensive and, before Perkin s synthetic mauve, millions of poor people lived their lives in untreated drab and dingy fibers. Even for the middle class, pieces of brilliantly dyed cloth were treasures to be reused from garment to garment and from year to year. It was the schoolboy William Henry Perkin and his successors who would give the world the ample abundance of tints that only the rich had previously enjoyed. 

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