Patent GB-482376-A (GB)
Title: Improvements in and relating to composite yarns
IPC: D02G3/24
Filed: 1936-09-29
Abstract: A composite yarn, which resembles a wool yarn, comprises one or more yarns of crinkled artificial filaments, having in the composite yarn at most only a small degree of twist, associated with one or more highly twisted yarns which, in the composite yarn, are so highly twisted that they possess the ability to shrink on treatment with hot aqueous liquors or associated with one or more yarns capable of being shrunk relatively to the crinkled yarn and in the composite yarn being shrunk and having a degree of twist less than cr<\>zepe twist; instead of a yarn or yarns of crinkled artificial filaments, one or more yarns which are not crinkled but which are crinkled after the association of the yarns may be employed.  The yarns may be associated together by a doubling twist and the speed at which the crinkled component is fed to the doubling device may be greater than the speed at which the other component is fed thereto; the proportion of crinkled yarn in the composite yarn may be substantially greater than the proportion of the other yarn.  The denier of the yarn or yarns of crinkled artificial filaments may be substantially greater than that of the other yarn or yarns, the tensile strength of the shrinkable yarn is preferably at least 2 grams per denier, at most 30 per cent of the total denier of the composite yarn is constituted by the high twist yarn or the shrinkable yarn and the yarns may be doubled together so that in the composite yarn the length of highly twisted yarn is greater than that of the crinkled yarn.  The crinkled yarn may also consist of partially or completely saponified cellulose acetate or other cellulose ester or may have a basis of cellulosic material but have been subject to a process of surface esterification or etherification or may have a basis of an organic derivative of cellulose and have been subjected to a process of esterification, e.g. as described in Specifications 448,816, 448,817, and 448,917 and they may have been stretched prior to crinkling.  The crinkled and shrinkable yarns may be different in character or, when the shrinkable yarn is highly twisted, they may be of the same material; the crinkled yarn and shrinkable yarn may be of the same material and the crinkled yarn coated with a resist which prevents the shrinking agent acting upon it or the shrinkable yarn may be stretched so that it is more sensitive to the shrinking agent than the crinkled yarn or the crinkled yarn may contain filaments that have been shrunk.  The highly twisted shrinkable yarns may be produced by the processes described in Specifications 437,019, 438,589, 438,590, and 438,591, [all in Group IX], the crinkled yarn may be produced by the processes described in Specifications 424,880, 442,073, and 464,981, [all in Group IX], or from flat filaments as described in Specification 459,781 and the crinkle may be fixed by the process described in Specification 455,021; the shrink able yarns, when having a basis of cellulose acetate or other organic derivative of cellulose, are preferably shrunk by the aid of organic shrinking agents as described in Specification 389,823 and the treatment of the composite yarns with shrinking agents may be carried out prior to, or subsequent to, the conversion of the yarn into a fabric.  Specification 482,425, [Group IX], also is referred to.