GB832363A - Improvements in or relating to the bulking of yarns - Google Patents

Abstract

832,363. Finishing yarns. HEATH & CO. Ltd., G. H. March 11, 1958 [Dec. 12, 1956], No. 37911/56. Class 120(3) Untwisted or low twist i.e. up to 3 turns per inch, multifilament yarn of thermoplastic material e.g. cellulose triacetate, copolymers of vinyl chloride and acetate, polyacrylonitrile, polyamides, polyesters, is bulked by progressing the yarn e.g. at a speed of 200 feet per minute, under low tension e.g. 3 grms., in contact with at least one heated surface which may be flat or curved, tubular or corrugated and of metal e.g. as provided by two successive stainless steel rods. The temperature of the surface e.g. 400‹-420‹F., which may approach or even exceed the melting point of the yarn material, and the extent of the contact of yarn therewith are such that heat-shrinkage, occurring in some of the filaments induces deformations in other filaments. As shown, yarn 12 passes from a bobbin 12, through an eye 16, beneath a guide rod 17, through a tensioner 18, tangentially over an arcuate heater 19 (heated directly by passage of electric current therethrough), over a guide rod 20, through an eye 21, it is lapped around delivery rollers 22, 23, passes through an eye 24 and is taken-up on a bobbin 13. The bulked product, Fig. 3 (not shown), may be given additional twist e.g. to 20 turns per inch.