Patent GB-494015-A (GB)
Title: Improvements in or relating to composite yarns
IPC: D02G1/18
Filed: 1937-04-20
Abstract: 494,015. Composite yarns. BELL, A. S., and WYLDE, J. R. April 20, 1937, No. 11294. [Class 120 (iii)] Composite yarns resembling wool yarns are made by associating one or more yarns of uncrinkled artificial staple fibre with one or more yarns which, after such association, are capable of being shrunk relative to the yarns of uncrinkled staple fibre, and thereafter shrinking said shrinkable yarns. The yarns may be associated by a light doubling twist or may be sized together; yarns of uncrinkled artificial staple fibre may be fed to the doubling device at a speed greater than the shrinkable yarns ; and the total denier of the yarns of uncrinkled artificial staple fibre is preferably substantially greater than that of the shrinkable yarns. The shrinkable yarns may be such that, after association with the yarns of uncrinkled artificial staple fibre, they are so highly twisted that they possess the property of shrinking on treatment with hot aqueous liquors and the shrinkage is effected by such treatment; the shrinkable yarns may be shrunk by chemical agents. The yarns of uncrinkled artificial staple fibre may be produced by the processes described in Specifications 424,683, 424,752, 424,830, and 424,879, and may have a basis of regenerated cellulose or of cellulose acetate or other organic derivative of cellulose which may be partially or completely saponified or may have a basis of an organic derivative of cellulose which has been subject to esterification, e.g. by the processes described in Specifications 448,816, 448,817, and 448,917, [all in Group IV]. The shrinkable yarn may have a basis of a different material from the uncrinkled staple fibre yarn and may be highly twisted so that it shrinks on treatment with hot aqueous liquors ; both kinds of yarn may have a basis of cellulose acetate, the shrinkable yarn having a higher or lower acetyl content; or where the uncrinkled staple fibre yarn has a basis of cellulose acetate or other organic derivative of cellulose, the shrinkable yarn may have a basis of a different derivative of cellulose, and of regenerated cellulose, of cellulose acetate or other cellulose ester which has been subjected to partial or complete saponification or may be of cotton, silk, or wool ; where the uncrinkled staple fibre yarn has a basis of regenerated cellulose, the shrinkable yarn may have a basis of cellulose acetate or other organic derivative of cellulose or may be a silk or woollen yarn. Composite yarns of a uniform chemical character may be obtained by using yarns naturally sensitive to shrinking agents and coating the uncrinkled staple fibre yarn with a reserve or by stretching the yarn to be shrunk or by shrinking the uncrinkled staple fibre yarn. When highly twisted crepe yarns having a basis of cellulose acetate or other organic derivative of cellulose are employed as the shrinkable yarns, they may be produced by the processes described in Specifications 437,019, 438.589, 438,590, and 438,591, and may be shrunk with the aid of organic shrinking agents as described in Specification 389,823, [Group IV].