GB759070A - Improved crimped artificial filaments - Google Patents

Abstract

759,070. Crimping yarns and filaments. IMPERIAL CHEMICAL INDUSTRIES, Ltd. Feb. 16, 1955 [March 3, 1954], No. 6201/54. Class 120 (3). Drawn filaments of a synthetic linear polymer, e.g. polymethylene terephthalates, polyamides, in the form of tow or yarn, are doubly crimped as by passage through a stuffer-box (e.g. as described in U.S.A. Specification 2,311,174) or gear-wheel crimper; optionally, heat-setting the crimp as by superheated steam, or dry heat by contact with hot surfaces, radiation heat, or heating by convection or conduction, and drying as by hot air, if necessary ; then subjecting the crimped filaments to one or more further crimping processes (which may be similar to the first) while under tension, as may be achieved by passage of the filaments over tensioning-pins, not exceeding that required to straighten the crimps applied during the preceding process. The filaments may be fed directly from one crimping apparatus to the next and rotated therebetween so that the additional crimping occurs in a different plane from that of the initial crimp, or yarn may be wound on bobbins, or tow fed into cans or wound on large beams, after each crimping step. The walls of the stufferbox or the gear-wheels may be heated or the tow may be heated prior to entry thereto. On emerging from the final crimping operation, a heat-set and dried tow spreads laterally into a sheet of separated filaments. this action being assisted by electrostatic charges which accumulate on the filaments, and in this form the filaments are suitable for dressing, as with lubricants, and subsequent stapling by cutting.