Rayon thread, making

Natural fibers go back to prehistoric days. Probably one of the early applications was the conversion of a fiber (possibly wool or cellulose) into thread or rope strong enough to be used in a snare, net, or cage. Literature as far back as the 17th century notes that people attempted to make fibers out of something other than cotton, wool, or flax. The first man-made fiber, known as artificial silk, was made in the 19 th century, when wood pulp was treated with nitric acid. The result was known chemically as cellulose nitrate and (eventually) commercially as Rayon. The commercial name referred to the sheen that has the brilliance of the sun. ... 

Cellulose acetate is less flammable than cellulose nitrate and has replaced the nitrate in many of its applications, in safety-type photographic film, for example. When a solution of cellulose acetate in acetone is forced through the fine holes of a spinnerette, the solvent evaporates and leaves solid filaments. Threads from these filaments make up the material known as acetate rayon. 

When viscose is forced through a spinnerelte into an acid bath, cellulose is regenerated in the form of fine filaments which yield threads of the material known as rayon. There are other processes for making rayon, but the viscose process is still the principal one used in the United States. 

Viscose can be forced through fine holes in a spinerette into an acid bath, giving the removal of the xanthate group and the regeneration of cellulose in the form of a fine filament or thread known as rayon. If instead, the viscose is forced through a narrow slit into an acid bath, cellulose is regenerated as a thin, transparent sheet that can be softened with glycerol to make cellophane. 

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