GB438589A - Improvements in or relating to the manufacture of crepe threads and crepe fabrics - Google Patents

Abstract

438,589. Yarns &c. BRITISH CELANESE, Ltd., and DREYFUS, H., 22, Hanover Square, London.-(Celanese Corporation of America, (partly) ; 180, Madison Avenue, New York, U.S.A.) Feb. 13, 1934, Nos. 4302/34, 4897/35 (divided out of 438,590), and 16243 /34. [Class 120 (iii)] Highly twisted crepe threads of filaments of organic derivatives of cellulose are twisted and steamed during the insertion of at least the last part of the crepe twist, in the absence of moisture in the case of cellulose ester or ether filaments, or in the presence of moisture in the case of filaments of cellulose ester or ether other than cellulose acetate. The threads may have been prepared by esterification of cellulose filaments without loss of filamentary form ; or they may be cellulose ester filaments which have been saponified superficially or partially throughout, either uniformly along their length or intermittently, or they may have been prepared from filaments of cellulose acetate which have been stretched whilst in a softened state, as described in Specifications 277,089, 323,790, [both in Class 120 (iii)], 370,430, 371,461; 438,584, and 438,585, [both in Group IV]. The threads may comprise filaments of different cellulose esters or ethers and filaments of other materials. The twist may be inserted in one or more stages, and is of the order of at least 70 turns per inch for a thread of 165 denier, and at least 85 turns per inch for thread of 115 denier, which gives a smooth cylindrical thread whose apparent sp. gr. is more than 75 per cent of the actual sp. gr. of the filaments. The threads may consist of continuous filaments or staple fibres, e.g. as prepared according to Specifications 424,683, 424,752, 424,830, and 424,879. Twisting may be effected by drawing off over the end of a rotating package, e.g. by means of the device described in Specification 304,806, [Class 120 (iii)], and passing the thread into a steaming chamber, which may consist of a steam pipe of the requisite diameter with inlet and outlet eyes arranged diametrically, of porcelain, stainless steel or the like. The threads may be moistened before steaming. A suitable steaming is obtained by passing the threads at 2-10 metres per minute through 3in. of steam. The threads may be stretched by 10-20 per cent during the twisting. Fabrics containing the crÛpe threads are subjected to a hot aqueous treatment to develop the crÛpe effect. Specifications 348,589 ; 437,019, [Group IV], and 438,590 also are referred to.