GB378319A - Improvements in artificial filaments, yarns, ribbons and the like and in processes for manufacturing the same - Google Patents

Abstract

Artificial filaments, yarns, ribbons, bristles, straws, &c. are delustred by incorporating therein a preformed water-insoluble bismuth compound, either by the addition of such to the spinning solution or by treatment of the materials with a suspension of the compound preferably in the presence of a swelling agent for the substance of the filaments. The method is applicable to artificial threads, &c. of the reconstituted cellulose type and to those made from inorganic esters of cellulose or from cellulose esters. Suitable bismuth compounds are bismuth oxychloride and hydroxide, or if coloured pigments are desired, bismuth oxides and sulphide; and the compounds are preferably used in very fine form as by fine grinding with water, oil or diethylene glycol, the particles being reduced to less than 5 microns and preferably less than 2 microns. To the spinning solution may be added diethylene glycol, heavy mineral oil, and olive, castor or other oil, and the pigment and the solution are preferably thoroughly mixed and subjected to the usual filtrations. Yarns &c. in addition to being delustred, have greater opacity and covering power, do not cut the thread guides &c., knit more closely, and have improved winding, twisting or knitting properties.