GB625748A - Improvements in or relating to the spinning of rayon - Google Patents

Abstract

Spinnerettes provided with a thin film of an organo-silicon compound are used for the spinning of viscose into acid baths containing salts, such spinnerettes possessing the property of not clogging during the spinning. The spinnerettes are cleaned with strong sulphuric acid, then washed in a weak alkaline bath, washed in water and dried so that no water is visibly present on the surfaces. The clean spinnerettes are exposed to the vapours of an organo-silicon halide, e.g. a mixture of CH3SiCl3 and (CH3)2SiCl2, which reacts with the water still present on the spinnerette surfaces to deposit a very thin silicone film. Any traces of acid may be removed by exposure to an alkaline vapour such as ammonia. The silicon compound may be applied in the liquid state by wiping the surface of the spinnerette. Suitable compounds which may be utilized include the alkyl-silicon-halides such as methyl, ethyl, propyl and butyl silicon chlorides and bromides, aryl compounds such as the phenyl-silicon-halides, aralkyl compounds such as the phenyl - methyl - silicon - halides, alkaryl compounds such as the tolyl-silicon-halides and similar alkyl-aryl halosilanes such as the chlorosilanes. These compounds may be used in mixtures. Specification 469,817 and U.S.A. Specifications 2,100,581, 2,294,154 and 2,306,222 are referred to.