GB450257A - Manufacture of a substitute for wool from viscose - Google Patents

Abstract

In a process for making fibres useful as a substitute for wool from viscose, continuous threads of cellulose xanthate are cut into staple fibres and then converted to cellulose fibres by treatment with a liquid at a temperature having a decomposing action on cellulose xanthate. Preferably the xanthate threads are stretched in the coagulation bath or between it and the cutting machine. Suitable spinning baths are ammonium sulphate solutions with or without sodium sulphate. Suitable decomposing liquids are glycerine, glycol, sulphonated oils (such as castor or olive oil), high boiling point solutions of inorganic salts, such as calcium chloride, or of organic acids such as oxalic acid, alcohols or ethers of high boiling point, ketones of high boiling point, e.g. cyclohexanone, hydrocarbons or their substitution products. A suitable temperature is about 100 DEG C. The time taken for the decomposition varies from a few minutes to a few seconds. The fibres which are well crimped are then washed. If the liquid used for the decomposition dissolves sulphur, the desulphurization step may be omitted. In an example viscose is spun from a nozzle with 800 perforations at 25 DEG C. in a 30 per cent ammonium sulphate solution and the fibre bundles thus produced are united to form thick bundles of more than 1000 deniers. These bundles are cut to staple and heated in glycerine to 120 DEG C. The crimped staple is separated, e.g. by conveyer sieves running over rollers and is freed by washing with water from adhering glycerine. It is then treated with solutions of soaping or brightening agents, dried and combed to produce a loose staple fibre stiver.