GB342743A - Improvements in the manufacture of artificial silk filaments - Google Patents

Abstract

The lustre and softness of artificial silks are modified by incorporating in the spinning solution fine particles of a non-volatile oleaginous material such as heavy white petroleum oil and of a pigment such as titanium dioxide insoluble in the solution and having a particle size less than 0,75 microns, and before spinning passing the solution through at least a portion of the usual filtering system. By filtering the solution, aggregations of particles are broken up, while the oleaginous material besides acting as a softening agent with respect to the filaments also serves to facilitate the filtering operation. In the case of nitrocellulose silk, the oil is dissolved in a portion of the alcohol-ether used as solvent, the titanium dioxide pigment is ground with the remainder of the solvent, the nitrocellulose is dissolved by thorough mixing in the solvent so prepared, and the solution obtained is subjected to the filtering operations usual before spinning. A similar procedure is adopted in the preparation of solutions of cellulose acetate in acetone, the oil being dissolved in a portion of the acetone or in ether. As an alternative procedure the oil may be mixed with the solution of the cellulose material. Specifications 243,350, 290,693 297,364, and 339,603, [all in Class 2 (ii), Cellulose &c.], are referred to.