GB507061A - Improvements in textile threads and fabrics - Google Patents

Abstract

507,061. Composite yarns; crimping yarns. FINLAYSON, D., and BEZANT; R. Dec. 4, 1937, No. 33620. [Class 120 (iii)] A crimped yarn is produced by doubling together one or more component threads, that have been crimped by setting therein twist imparted by a false twisting device fitted with a yarn trapping device with which the thread makes an angle of contact of more than 90‹, and one or more component threads having a lower or less permanent degree of crimp. The components may be obtained by the methods described in Specifications 424,880, 442,073, and 464,981, the more permanently crimped threads being produced by arranging the angle of contact of the thread leaving the false twisting device with the trapping device to be greater than 90‹, e.g. 180‹ up to 360‹ or more, and the less permanently crimped threads being produced by arranging the angle of contact to be less than 90‹ or when the latter threads are of cellulose acetate and preferably containing filaments of flat cross-section they may be crimped by the action of a hot aqueous medium. The components having the higher or more permanent degree of crimp may be fed, in the doubling operation, at a lower rate than the remaining components and two of the composite crimped yarns may be doubled together. As shown in Fig. 2, the yarn 33 to be given the higher or more permanent degree of crimp, is passed around the trapping hook 32 of the apparatus described in Specification 464,981 so that it is constrained to turn through a substantial angle and make an angle of contact with the hook of more than 90‹ and in Fig. 4, an additional hook 34 is provided on the false twisting device 14 to give the increased angle of contact. Specifications 482,376, 482,426, and 503,923 also are referred to.