Silk fibers production process

Reeling n. In silk fiber production, the process of unwinding the cocoon. 

The silk production process must have some built-in temporal, mechanical, and chemical flexibility. This is evident in the ability of the animal to switch from long-duration storage of the proteins (in an aqueous solution state) to high-speed extrusion spinning (into an insoluble fiber with... 

Wang, M., Yu, J.H., Kaplan, D.L., and Rutledge, G.C. "Production of submicron diameter silk fibers under benign processing conditions by two-fluid electrospinning". Macromolecules 39(3), 1102-1107 (2006). 

A model for the process of silk pseudomorph formation on bronze is proposed, including solution of copper ions, transport inside the swollen silk, reaction with available anions, and deposition of the resulting products. The maintenance of the outer physical structure of the fiber is attributed to the network of the polymer chains of silk and the maintenance of some structural integrity during degradation. The presence of green and black pseudomorphs of equal size in the same location on the halberd led to a discussion of the possibility of difierential replacement of dyed silk fibers and undyed silk fibers. 

Silkworm is often processed via the production of fibroin solution where degummed silk is dissolved, and thus the inherent mechanical properties of the silk fibers are lost and any damage caused by the removal of sericin becomes insignificant. In its simplest form, fibroin can be regenerated into a film or coated onto other materials [90, 51, 62, 9], The manufacture of nano-Hydroxyapatite-silk sheets [135,42] has also been reported. 

From 1910 onward waste filament yam had been chopped into short lengths suitable for use on the machinery designed to process cotton and wool staples into spun yams. In the 1930s new plants were built specifically to supply the staple fiber markets. During World War II the production of staple matched that of filament, and by 1950, staple viscose was the most important product. The new spun-yam oudets spawned a series of viscose developments aimed at matching the characteristics of wool and cotton more closely. Viscose rayon was, after all, silk-like. Compared with wool it lacked bulk, residence, and abrasion resistance. Compared to cotton, it was weaker, tended to shrink and crease more easily, and had a rather lean, limp hand. 

In the original process the cellulose nitrate itself was used as the fiber (hence its satirical description as mother-in-law silk ). The regenerating agent is ammonium hydrosulfide. The basic process was first demonstrated by J. W. Swan in London in 1885 but commercialized by Count L. M. H. B. de Chardonnet ( Father of the rayon industry ) in France in 1891 and operated there until 1934. The last working factory, that in Brazil, was burnt down in 1949. The other processes for making rayon fibers by regenerating cellulose ( viscose, cupram-monium) gave superior products. See also Rayon. 

Natural fibers such as cotton can be chemically modified to form rayon or acetate. Rayon was first called artificial silk. In the viscose process, cellulose is dissolved in sodium hydroxide, pushed through spinnerets, and treated with acid to harden. Treatment with copper compounds and ammonia is used to form hosiery yams. Acetate (or cellulose acetate), produced by treating cotton with acetic acid and acetic anhydride, is also used in production of clothing. 

Recently, Foo et al. (2006) produced some novel nanocomposites from spider silk-silica fusion (chimeric) proteins. The composite morphology and structure could be regulated by controlling processing conditions to produce films and fibers. Silk and biomineralization being natural inspiration sources will allow production of numerous new materials in various fields of application. 

Tussah or wild silk is obtained from caterpillars that are not cultivated, living naturally on mulberry, cherry, or oak trees. The cocoons are gathered by and processed by hand, resulting in an uneven and irregular product. Tussah is tan or brownish, depending on where the caterpillar had been living and what it had been eating. Tussah is often mixed with other fibers to produce hybrid fabrics. 

In a previous section, data and plots were given showing the rapid rise in consumption and production of manufactured fibers at the expense of natural fibers. The principal reason for this has been the wide range of manufactured fiber variants that can be produced from a single fiber-forming polymer. The wide range of polymers available, each with its particular properties, adds yet another dimension. This is not to say that there is only one type of cotton, wool, silk, or asbestos fiber there are many varieties of natural fibers, but their supply is limited by natural factors such as climate and genetics. The relative availabilities of manufactured fiber types can be altered by controlled chemical-process... 

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