Viscose

VISCOSE

Viscose was discovered by two English chemists, Charles F. Cross and E. J. Be van, working in collaboration at Kew, near London, who found that when cellulose was treated with disulphide of carbon in the presence of caustic soda, it was converted into a golden yellow plastic compound which dissolved readily in water. A solution of the plastic was of such viscosity that it was named " viscose," a name that was destined to become world famous, seeing that round about 88 per cent of the world production of rayon is now made by the viscose process. In 1892 Cross and Bevan were granted a patent on the viscose process and it was applied to many purposes before the production of a textile thread was successfully accomplished. Fundamentally, the manufacture of viscose rayon is fairly simple. The raw material may be wood pulp, pulp from cotton linters, or a mixture of the two. The greater part of the world's viscose is made from wood pulp. Viscose rayon manufacture comprises seven distinct treatments as follows: - 1. Making and purifying the cotton or wood pulp which forms the cellulose base. 2. Caustic soda treatment of the cellulose base thereby forming alkali cellulose. 3. Treatment of alkali cellulose with carbon disulphide, forming cellulose xanthate. 4. Dissolving the cellulose xanthate in weak caustic soda to form cellulose solution or viscose. 5. Spinning viscose into yarn. 6. Bleaching, purification and finishing of the yarn. 7. Preparing the yarn for weaving and knitting.