Patent GB-776410-A (GB)
Title: Novelty yarn and method and apparatus for the production thereof
IPC: D02G1/16
Filed: 1955-05-26
Abstract: 776,410. Spinning and finishing yarns and threads. CELANESE CORPORATION OF AMERICA. May 26, 1955 [May 28, 1954], No. 15215/55. Classes 120 (2) and 120 (3). A varying denier yarn of continuous filaments of cellulose derivatives e.g. esters such as cellulose acetate, propionate, butyrate, acetate-propionate or butyrate, esters such as ethyl- or benzyl-cellulose, or polyesters such as polyethylene terephthalate, or polyamides such as polyhexamethylene adipamide, or regenerated cellulose or blends thereof, comprises bulky portions, in which individual filaments are convoluted into coils, loops,. and whorls at random intervals along their length, alternating with portions which are less bulky and may be free of such convolutions and of greater length and lustre: the transition between portions may be abrupt or gradual. In the production of the yarn a bundle of filaments, as in the form of a yarn, is passed under tension through a zone wherein the filaments are subjected to forces, as may be produced by a turbulent fluid stream, to separate and agitate them sufficiently to form the convolutions, subjected to intermittent variation in tension, removed from the zone under a tension insufficient to straighten out the convolutions, and twisted. As shown in Fig. 1, yarn 12 is drawn by driven feed rollers 11 at constant speed from a bobbin 13, through guides 14 and 16 and delivered to an air jet apparatus 17 (wherein high velocity turbulence is produced) which it leaves by an outlet offset from the inlet, impinges on a plate 36 at an angle to the surface thereof, passes under a smooth-surfaced roller 37 driven at a constant peripheral speed less than that of the rollers 11, over guides 38 and 39, finally through a traveller 41 of a ring twister 42 to be takenup by a bobbin 43 : intermittent variation of tension in the yarn is applied by means of a freely-rotatable roller 44 having a friction surface (rubber, felt, or cork) which is rocked by a cam 47 actuating a lever 46 to engage the roller 37 so that the yarn is alternately, but for varying periods, gripped in the nip therebetween so that the yarn is twisted between this nip and the bobbin 43 and the tension exerted by the twister 42 is limited to such part of the yarn, and then disengaged therefrom so that the yarn slips freely on the roller 37 and the yarn travelling from the jet 17 is tensioned and twisted over a greater length by the twister 42. In another tensioning arrangement, Fig. 2, roller 44 is replaced by a similar roller 51 which normally is urged, as by its own weight, into engagement with the roller 37 and is disengaged therefrom by means of a cam 56 actuating a linkage 54 and bar 52: alternatively, the yarn 12 is intermittently engaged and disengaged by the roller 37 and a friction-surfaced roller 57 having one or more cut-out portions, as at 58. The variation in tension may be applied on the input side of the jet 17: as shown in Figs. 5 and 6, the yarn is passed through a gate-type tensioning device 59 which comprises a stationary leaf 62 towards which a movable leaf 61 is urged by a spring 63, attached to a finger 64, to maintain tension, and is separated therefrom by means of a cam 66 projections 67 of which operatively engage the finger 64. Reference has been directed by the Comptroller to Specification 732,929.