Textile remains

Figure 7.1 Archaeological textile remains preserved in iron corrosion, Macro photograph (a) with scanning electron micrograph (b) (original magnification 2000x). The iron corrosion products have formed a negative cast around the wool fibers prior to their degradation many centuries before examination. (Photo R. C. Janaway.) (See color insert following p. 178.)...

Most soil microorganisms are inhibited by cold and freezing conditions. Low, but not freezing, temperature will slow bacterial activity. For biodeterioration to be inhibited over longer timescales, soil conditions need to be well below freezing. In the 1980s the frozen bodies of three seamen who had been buried in the Canadian arctic were exhumed. The bodies exhibited extensive soft-tissue preservation, and the textile remains were in excellent condition (Beattie 1992 Beattie and Geiger 1987). 

Markets for elertronic consumer products, motor vehides, and textiles remain the most prominent for processors of FR plastic compounds, according to year 2007 and 2008 market surveys. In terms of volume FR use in PP and PE surpasses the volumes used in all noncommodity polymers, and it also exceeds (and is growing faster than) FR use in PVC as weU. This stems from POs use for wire and cable coverings, electrical/elertronic devices, stadium seating, films and fibers, and various construction applications—particularly in market sectors that have seen increasingly more rigorous fire codes [5-1, 5-2, 5-3). 

Traditional cotton — a unicellular, natural fiber that makes a soft and breathable textile — remains a mainstay of the glove industry. Cotton may be used in a canvas or jersey form, depending on the glove construction style (woven, knit or seamless knit). It may also be combined with polyester and other synthetics, making it very versatile. 

It is to be noted however that these textiles remain static, passive (unswitchable, non--dynamic) camouflage materials. Applications for such textiles have also been claimed in ESD/antistatic coatings for industrial belts, e.g. in coalmines, and personnel uniforms, e.g. for explosion-proofness. 

Synthetic Fiber and Plastics Industries. In the synthetic fibers and plastics industries, the substrate itself serves as the solvent, and the whitener is not appHed from solutions as in textiles. Table 6 Hsts the types of FWAs used in the synthetic fibers and plastic industries. In the case of synthetic fibers, such as polyamide and polyester produced by the melt-spinning process, FWAs can be added at the start or during the course of polymerization or polycondensation. However, FWAs can also be powdered onto the polymer chips prior to spinning. The above types of appHcation place severe thermal and chemical demands on FWAs. They must not interfere with the polymerization reaction and must remain stable under spinning conditions. 

Textiles. Microwave drying of textiles is under investigation, in addition to the possible uses for curing of impregnated and dyed fabrics (182). A microwave clothes dryer for consumer or commercial apphcation is also under discussion (183). Considerable developmental work and media pubhcity have occurred. Problems remain, however, particularly relating to arcing and resonant heating of metal objects that may be present in a load of clothes. These problems may be alleviated by operation at 915 rather than 2450 MHz (184). 

Commercial and Artificial Processing. Commercially, silkworm cocoons are extracted in hot soapy water to remove the sticky sericin protein. The remaining fibroin or stmctural sdk is reeled onto spools, yielding approximately 300—1200 m of usable thread per cocoon. These threads can be dyed or modified for textile appUcations. Production levels of sdk textiles in 1992 were 67,000 metric tons worldwide. The highest levels were in China, at 30,000 t, foUowed byJapan, at 17,000 t, and other Asian and Oceanian countries, at 14,000 t (24). Less than 3000 metric tons are produced annually in each of eastern Europe, western Europe, and Latin America almost no production exists in North America, the Middle East, or Africa. 1993 projections were for a continued worldwide increase in sdk textile production to 75,000 metric tons by 1997 and 90,000 metric tons by 2002 (24). 

Asbestos fibers have also been widely used for the fabrication of papers and felts for flooring and roofing products, pipeline wrapping, electrical insulation, etc. Asbestos textiles, comprising yam, thread, cloth, tape, or tope, also found wide apphcation in thermal and electrical insulation, friction products in brake or clutch pads, etc. In recent years, some of these appHcations have decreased to various extents, although others remain fairly active, typically in friction materials. 

Disperse—Vat Combinations. These require a two-step fixation. The disperse dye is fixed first, usually by dry heat, followed by impregnating of the textile with an alkaU and reducing agent solution and short steam fixation for the vat dye. The selected disperse dyes fixed in the polyester fiber are not destroyed by the reducing agent, but disperse dye remaining on the cellulose is destroyed. 

The polymers are of interest as water-soluble packaging films for a wide variety of domestic and industrial materials. (Additional advantages of the poly(ethylene oxide)s are that they remain dry to the feel at high humidities and may be heat sealed.) The materials are also of use in a number of solution application such as textile sizes and thickening agents. As a water-soluble film they are competitive with poly(vinyl alcohol) whereas in their solution applications they meet competition from many longer established natural and synthetic water-soluble polymers. 

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