GB813876A - A process for the production of threads by the viscose spinning process - Google Patents

Abstract

Threads are produced by spinning viscose in an acid bath containing more than 2.5 per cent by weight of zinc sulphate and 0.2-5 per cent by weight of formaldehyde, there being added to the viscose, in a proportion of 0.5-5 per cent by weight, calculated on the cellulose content of the viscose, and/or to the spinning bath, in a proportion of 0.5-5 g/kg. of spinning bath, one of the following compounds: (1) a polyalkylene glycol, e.g. polyethyleneglycol; (2) a reaction product of a polyalkyleneglycol with an amine, e.g. a fatty amine, an alcohol, e.g. a fatty alcohol, a fatty acid or an aromatic acid, (3) an aliphatic or aromatic monoamine, diamine or other polyamine; (4) a quaternary ammonium compound, e.g. a quaternary ammonium base or an oxyethylation product thereof; (5) a mono- or di-thio carbamate; (6) an imidazole, e.g. 2-mercapto-benzimidazole; or (7) a thiazole, e.g. mercaptothiazole. The spinning bath may contain sodium sulphate and the relative proportions of the salts contained in the spinning bath may be so adjusted that the sodium sulphate content is lowered with increasing zinc sulphate content, a sodium sulphate content of 17 per cent by weight corresponding to a zinc sulphate content of 4 per cent by weight and a sodium sulphate content of 12 to 13 per cent by weight corresponding to a zinc sulphate content of 8 per cent by weight. The thread is preferably guided through the spinning bath as far as possible without tension and subjected to a stretching process in a second bath, containing about 0.2-3 per cent by weight of sulphuric acid and small proportions of sodium and zinc sulphates, maintained at a temperature higher than 80 DEG C. When added to the viscose, the additives are preferably introduced in the mixer, although they may be added during the breaking up of the fibres or during the sulphidizing operation, or just before spinning.