GB921583A - A process for the manufacture of improved false-twist-crimped bulked filament yarn - Google Patents

Abstract

921,583. Spinning and finishing yarns. IMPERIAL CHEMICAL INDUSTRIES Ltd. Aug. 7, 1959 [May 13, 1958], No. 15240/58. Class 120 (3). A torqueless, twist e.g. false-twist, crimped, bulked yarn of synthetic filaments has crimp elongation less than 15% and shrinkage per unit length in hot water or steam of less than 10%. (Crimp elongation is measured by first applying a load of 0.0033 grams/ denier, to straighten the yarn so that its original length can be measured, then adding a load of 0.04 grams/denier and determining the extension, with crimp pulled out, which results). The basic yarn is textured by twisting e.g. 10-170 turns/ inch, setting the twist e.g. by heating, untwisting the yarn, winding the resultant crimped yarn on to a package by feeding it thereto at a speed higher than the wind-up speed, and then subjecting the yarn (which may remain on the package) to a hot fluid or gaseous treatment e.g. in a steam oven, which may form part of a dyeing process. The filaments may be polyamide, polyester, polyacrylonitrile or polypropylene. The first heat-setting may be effected by electrically or fluid heated tubes or curved or straight contact plates or elements, hot fluids, or infra-red heating, and may be insufficient to render the crimp permanent (such permanence being ensured by the fluid or gaseous treatment). In the apparatus shown, which corresponds to the apparatus of Specification 881,729 with means (not shown) for subjecting the yarn to the hot fluid or gaseous treatment, yarn 1 is fed through a heater 2 and a false-twister 3, with predetermined speed differential or equality between feed and withdrawal, by feed and take-up roll systems 4 and 5, thence to traverse mechanism 7 which lays it on package 8 driven by roller 9 at a 10-30% lower speed than that of system 5.