Viscose
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Look up viscose in Wiktionary, the free dictionary. |
Viscose is a viscous organic liquid[1] used to make rayon and cellophane. Viscose is becoming synonymous with rayon, a soft material commonly used in shirts, shorts, coats, jackets, and other outer wear.
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[edit] Manufacture
At first pulp is dissolved in caustic soda and after steeping it for a specified period of time it is shredded and allowed to age. Aging contributes to viscosity of viscose. The longer the ageing time the less viscosity it will have. The aged pulp is then treated with carbon disulfide to form a yellow-colored cellulose xanthate, which is dissolved in caustic soda again, but of a lower concentration. This is the starting stage of viscose formation. During the process an acetate dope is added to alkali cellulose which is necessary for the yarn lustre.
[edit] Pollution
Viscose currently is becoming less common because of the polluting effects of carbon disulfide and other by-products of the process, forcing some factories to close. One way to comply with sulphur emission standards is to install a wet sulfuric acid process unit which recovers sulfur compounds to sulfuric acid or use the Lyocell process which uses N-Methylmorpholine N-oxide as solvent.
[edit] History
French scientist and industrialist Hilaire de Chardonnet (1838-1924)— who invented the first artificial textile fiber, artificial silk—created viscose in Échirolles in 1891. Three British scientists, Charles Frederick Cross, Edward John Bevan, and Clayton Beadle patented the process in 1902.
[edit] Products made from viscose
[edit] External links
[edit] References
- ^ Answers.com Dictionary at http://www.answers.com/viscose?nafid=3 (n. A thick, golden-brown viscous solution of cellulose xanthate, used in the manufacture of rayon and cellophane.)
