GB438590A - Improvements in or relating to crepe threads and fabrics - Google Patents

Abstract

438,590. Twisting artificial silk ; woven fabrics. DREYFUS, H., 22, Hanover Square, London.-(Celanese Corporation of America, (partly) ; 180, Madison Avenue, New York, U.S.A.) Feb. 9, 1934, Nos. 4303 and 19875. [Classes 120 (ii), 120 (iii), and 142 (iv)] Cellulose acetate threads are twisted to a high degree in at least two stages, and during at least the final stage of twisting the threads are steamed under conditions such that moisture is present. The steam may be at atmospheric or elevated pressure. The tension on the threads during twisting in the presence of moist steam may be sufficient to effect a considerable elongation with reduction in denier. The threads may consist of continuous or discontinuous filaments which may contain pigments or loading materials. Twisting may be effected by drawing the thread over the end of a rotating package through a guide fixed in line with the axis of rotation, and passing it on its way to a winding bobbin, through steam. The steaming device is arranged so that twisting takes place while the thread is under the influence of steam. Flyers or floating ring devices for restricting the ballooning of the thread may be used The steaming device may be a chamber situated vertically above one or more twisting spindles and provided with inlet and outlet holes for the threads. It may take the form of a horizontal pipe. The presence of moisture may be ensured by the use of wet steam or by arranging for condensation. A free escape of steam on to the thread as it is drawn from the spindle may be effected. A shield or funnel may be fitted round the thread approaching the steaming device. The threads may be moistened with water before twisting or just before entering the steaming device. The threads produced are smooth and cylindrical. The amount of twist may be such that the apparent specific gravity of the thread is more than 85 per cent of the actual specific gravity of the component filaments. The threads may be sized with casein, egg-albumen, linseed oil, or other substance at any stage of the manufacture. The threads may be associated, in the production of fabrics, with low or high twist threads of cellulose acetate, regenerated cellulose, natural silk, or other material. In the weft, pairs of crÛpe threads of left-hand twist may alternate with pairs of right-hand twist crepe threads, and the warp may contain low twist threads. The fabrics may be subjected to hot aqueous treatment in order to obtain crepe effects. Specifications 304,806, [Class 120 (ii)], 348,589, 424,683, 424,752, 424,830, and 424,879 are referred to.