GB793527A - Improvements in the manufacture of cellulose acetate textile materials - Google Patents

Abstract

Cellulose acetate filaments, yarns, fabrics and other textile materials, in the production of which an acetone solution of cellulose acetate has been wet-spun into a coagulating bath comprising a solvent for the cellulose acetate diluted with sufficient water to render it a non-solvent, are given a uniform lustre by treatment with an alcohol containing up to four carbon atoms in the molecule, especially a monohydric alcohol completely miscible with water, preferably ethyl alcohol. The coagulating bath is preferably aqueous acetone or aqueous diethylene glycol diacetate. The alcohol may contain water or other substances, but these should preferably be neither solvents nor strong swelling agents for cellulose acetate, and the treating liquid should contain at least 80 per cent and preferably at least 85 per cent by weight of the alcohol. The material may be treated at any stage after the actual spinning operation. For example, a freshly spun yarn may be washed with the alcohol at 20-30 DEG C. to remove coagulating liquid from it, or a yarn which has already been washed may be treated before or after it is dried. A fabric may be treated before or after it is dyed or otherwise finished. The textile material is preferably treated at above about 30 DEG C. but not above about 60 DEG C., e.g. ethyl alcohol is best used at about 45-55 DEG C. The duration of the treatment may be from a few seconds to 15 minutes or more. In an example a 60-denier cellulose acetate yarn, which has been formed by extruding an acetone solution of cellulose acetate into 34 per cent aqueous diethylene glycol diacetate at 34 DEG C. and drawing the yarn at 40 metres per minute over a friction device to wipe off adhering coagulant, is forwarded to a washing device comprising a pair of mutually inclined thread-advancing rollers. The yarn makes a total of 60 wraps round the rollers, and industrial spirit at about 50 DEG C. is applied at a rate of 5 litres per minute to the upper end of the lower roller. The yarn, after leaving the washing device, is at once dried by passing it round a pair of heated thread-advancing rollers. Specifications 720,187, 787,556, 787,557, 787,558, 787,559, 787,560, 787,561, 787,562, 787,563 and 787,564 are referred to.