GB481508A - Improvements in the manufacture of artificial filaments, foils, films and like materials - Google Patents

Abstract

Filaments or yarns of organic derivatives of cellulose, such as the esters, ethers and mixed ether - esters, containing a plasticizer, are stretched at temperatures above 30 DEG C. in a fluid medium containing about 10 per cent or less of an organic softening agent of medium or high volatility. The medium may be water or steam, or the liquid or vapour of organic substances having substantially no swelling action on the cellulose derivative, e.g. benzene, toluene, petroleum ether or other aliphatic or aromatic hydrocarbons, propyl and isopropyl ethers and alcohols, methyl and ethyl alcohols, or esters such as ethyl and isopropyl acetates. Liquid softening media may contain salts such as sodium chloride, sulphate, acetate, phosphate or nitrate, p ammonium chloride or nitrate, magnesium or calcium chloride in concentrations up to saturation point. The filament containing plasticizers are prepared by spinning a solution containing plasticizer or by passing the filaments after formation into a solution of the plasticizer in, e.g. water, benzene, ether, or carbon tetrachloride. Specifications 438,585, 438,586, 438,587, 443,707, 443,773, and 469,749 are referred to.