GB482425A - Improvements in and relating to composite yarns - Google Patents

Abstract

482,425. Yarns. FINLAYSON, D., and LEVERS, J. F. Sept. 29, 1936, Nos. 25379/37 and 25380/37. Divided out of 482,376. Drawings to Specification. [Class 120 (iii)] A composite yarn, resembling a wool yarn, comprises one or more yarns of crinkled cellulose acetate having in the composite yarn at most only a low degree of twist, associated with one or more high twist yarns having in the composite yarn a degree of twist such that they will shrink on treatment with hot aqueous liquor and the proportion of crinkled yarn in the composite yarn being substantially greater than the proportion of high twist yarn. The yarns may be associated by a doubling twist and a length of high twist yarn may be doubled with a greater length of crinkled yarn. The denier of the crinkled yarn is preferably substantially greater than that of the high twist yarn and at most 30 per cent of the total denier of the composite yarn is constituted by the high twist yarn. The high twist yarn may be of high tensile strength. The crinkled yarn may be produced by subjecting cellulose acetate filaments of flat cross-section to the action of hot aqueous liquors and the spinning solution may contain a plasticizing agent as described in Specification 459,781. The crinkling may be produced by twisting yarn of cellulose acetate filaments, setting the twist and then removing at least part of the twist as described in Specifications 424,880, 442,073, and 464,981 or a yarn or bundle of flat filaments may be crinkled by subjection to one of these processes and, either before or after such treatment, subjected to the action of hot aqueous liquors. The high twist yarn may be crepe shrunk after the doubling operation by treatment with hot aqueous liquors. The crinkled filaments may be continuous or discontinuous and the high twist yarn may be of a natural or artificial material or it may be of normal cellulose acetate subjected to a process such as described in Specifications 448,816, 448,817, and 448,917, [all in Group IV]. The high twist yarn is preferably of high tenacity and may have been stretched or partially or completely saponified or the twist may be inserted while the yarn is under the influence of steam or hot water as described in Specifications 437,019, 438,589, 438,590, and 438,591. It is preferred to insert the doubling twist in the same direction as the original twist in the high twist yarn. Examples of composite yarns of components of various deniers and twists and of various doubling twists are given. Specifications 455,021, 474,401, and 474,402 also are referred to.