GB732929A - Bulky yarns and methods and apparatus for the production thereof - Google Patents

Abstract

732,929. Producing voluminous yarns and woven fabrics. DU PONT DE NEMOURS & CO., E. 1. Dec. 15, 1952 [Dec. 14, 1951], No. 31761/52. Classses 120(2), 120(3)' and 142(4). [Also in Group VIII] In the production of a multifilament voluminous yarn resembling spun staple and comprising loops irregularly spaced along its surface to provide a lateral interfilament spacing, continuous filaments within a bundle e.g. a dry yarn, are separated by passage through a moving fluid wherein is created a zone of such turbulence that the filaments are agitated sufficiently to form the individual filaments into crunodal loops and other convolutions, such as coils and whorls, at random intervals along their lengths and irregularly spaced on different filaments, Fig. 3 ; the filaments are withdrawn abruptly and under light tension so that the convolutions are not removed and are assembled Fig. 4, and may be twisted, Fig. 5, to hold the convolutions in place during which process snarls may be formed by entangled loops, a, b, c, Fig. 7 ; a permanent set may be imparted to the convolutions by steaming. The Specification describes examples applicable to yarns comprising filaments of polyacrylonitrile, vinyl chloride-acrylonitrile copolymer, polyethylene, polyester, nylon, cellulose acetate, viscose rayon, glass, raw China silk, and blends thereof. As shown in Fig. 1, twisted or untwisted yarn 22 passes between feed rolls 25, 26 to an air nozzle 27, consisting of a compressed air pipe 28 secured to a tube 29, on leaving which the yarn is blown apart, whipped around by the turbulent air and swirled into the convolutions : the loose bundle of filaments is taken up by rolls 32, 33 and wound on a down-twister. The stream-lined air nozzle 41 of Fig. 8 enables automatic stringing-up by means of an adjustable member 42 having a conical end 43 through which the yarn is introduced into the air stream. In another modification, Fig. 9, air is introduced into a chamber 49, passes through a helical passageway formed by an adjustable screwmember 50, which gives the air a swirling motion, and leaves through an orifice 51 in a plug 52 screwed into the nozzle body, and may be broken up and deflected by a baffle 53: yarn is passed by a tube 55 through the member 50 to the vicinity of the orifice 51 where it is caught by the air stream. Woven fabrics. A 2 X 2 twill weave fabric may be produced from the voluminous yarn.