GB313816A - Improvements in or relating to the manufacture of artificial textile fibres - Google Patents

Abstract

313,816. Sever, W., and Speakman, J. B. April 3, 1928. Divided on 300,221. Ammoniacal copper and unspecified solutions of cellulose or cellulose derivatives, processes for making filaments form.-Artificial filaments having a curled or crimped form similar to that of wool are prepared fom cellulose or cellulose derivatives by a multiple stage coagulation process in which the temperatures and concentrations of the cellulose solution and of the coagulating baths are such as to cause the outer and inner portions of each filament to undergo different treatment, with the result that the filaments shrink on drying and crinkle or curl individually. The first coagulating bath is diluted or modified so that the filaments are not completely coagulated therein. For example, a cuprammonium solution of cellulose may be spun at a temperature not exceeding 30‹ C. into an aqueous solution of caustic soda or caustic potash of 8‹ Tw. or less, or into an aqueous bath containing sodium or magnesium sulphate in an amount not exceed. ing 3 per cent by weight. Alternatively, substances such as ammonia, cuprammocium hydrate and other cuprammonium compounds. or glucose or other sugar may be added to the initial bath to reduce its coagulating power. The second bath may comprise a dilute aqueous solution of a mineral acid at a temperature not exceeding 30‹C.