GB410805A - Improvements in the manufacture of yarn from continuous filaments - Google Patents

Abstract

410,805. Producing yarns of fibrous character from filamentous material. BRITISH CELANESE, Ltd., 22, Hanover Square, London, HALE, F. C., and TYCE, G. C., c/o British Celanese, Ltd., Spondon, near Derby. Nov. 18, 1932, No. 32636. [Classes 120 (ii) and 120 (iii).] To produce yarn having the appearance of a spun yarn from continuous filaments, a number of filaments are gripped at two points in their length by means adapted to cause them to follow a sinuous path and are subjected to a breaking-load between the gripping points, so that they are broken and formed into associated fibres, and collected as by twisting and winding. The material may be subjected to further twisting with or without draft. The grippers conveniently are constituted by grooved rollers with teeth of rounded contour and preferably of involute profile, so as to grip the filaments 5 between the faces a, b, Fig. 3, the pressureangle being from 45-60‹ and the depth of the teeth about <1>/40". The grooves may be parallel to the axis of the roller or helical, the latter arrangement enabling the loading to be reduced. One roller may be plain. The rollers may be of steel or other metal, or may be made of material, such as canvas or linen with a synthetic resin or other binder and carborundum or other abrasive incorporated therewith. The filaments may be artificial, such as cellulose acetate or other organic derivative of cellulose, viscose, nitrocellulose, and cuprammonium yarn. As shown in Fig. 4, gripping-rollers 22, 23 rotating faster than rollers 20, 21 are provided so that the filaments 5 are extended beyond the breaking point and are twisted by a cap spindle-apparatus 25. Nip rollers 18, 19 feed the filaments under constant tension from a supply package 6. If desired supporting means such as a travelling band may be arranged between the gripping-rollers to support the filaments and to prevent wastage. The grip of the rollers is regulated by braking the upper rollers by a bridge-piece 28, and the grip of the front pair 22, 23 is increased relatively to the back pair by suitable adjustment of a bolt and nut 26 in the bridge-piece to ensure even delivery. The filaments may be rendered temporarily brittle prior to breakage, as described in Specification 410,745, the lower roller roller 20, the roller 18 or an auxiliary cooling roller being made hollow to receive refrigerating material, or cooling pipes may be arranged between the nips of the rollers. The filaments may be conditioned after breakage, as described in Specification 411,506, their strength may be modified at intervals in their length, as described in Specification 403,739, and they may vary in denier at intervals along their length as described in Specification 403,738. More than one bundle of filaments may be united at the twisting-device, and the bundles may be drawn prior to being twisted and wound as described in Specification 410,745. Hygroscopic bodies may be applied as described in Specification 387,003 to prevent electrification, for example in the case of cellulose acetate. In the Provisional Specification it is stated that roughening media of an insoluble type, or soluble and applied as described in Specification 372,797, may be used to increase adhesion between the fibres and, desirably, applied before breaking the filaments.