viscose process (vĭsˈkōs) [key], method widely used for the commercial preparation of rayon. Cellulose, prepared from either wood pulp or, less commonly, cotton linters, is treated with sodium hydroxide (an alkali) and then with carbon disulfide, the resulting product being a substance called cellulose xanthate. Dissolved in sodium hydroxide, this alkaline cellulose xanthate forms a thick solution called viscose. Rayon yarn is made by forcing the viscose through tiny openings in a spinneret into an acid solution, which coagulates it in the form of fine strands. Most of the rayon manufactured today is produced by this method, al though other processes are also in use. The viscose process was discovered in 1892 by the English chemist Charles Frederick Cross and his collaborator, Edward John Bevan.
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