Patent GB-816106-A (GB)
Title: Improvements in yarns and in processes and apparatus for producing yarns
IPC: D02G3/36
Filed: 1955-08-03
Abstract: 816,106. Spinning yarns and threads. DEERING MILLIKEN RESEARCH CORPORATION. Aug. 3, 1955 [Aug. 3, 1954; Sept. 16, 1954], No. 22320/55. Classes 120(2) and 120(3) A yarn comprises continuous filaments (at least 10) within which is entwined staple length fibre material constituting at least 30 per cent by weight of the yarn and distributed uniformly or concentrated at random intervals to produce a smooth or slubbed yarn. The filaments may be of polyester, polyamide, polyacrylonitrile, copolymers of acrylonitrile and vinyl acetate, viscose rayon, cellulose acetate, silk, glass, or synthetic protein material, and the fibres may be staple of these filament materials or of metal, wool, cotton, flax, or admixtures thereof. In the production of the yarn, an electrostatic charge is imparted to a slightly twisted or twistless strand of the filaments along at least a portion of its length so that the filaments are rendered mutually repulsive and thereby separate, the staple fibre is introduced into the separated filaments or parts thereof, and, the filamentary assembly is twisted (to at least five turns per inch). The charge may be induced by bringing a strand of the filaments into frictional engagement with a different material presenting a firm, durable, non-adhesive surface, e.g. glass, synthetic resin such as pheol-formaldehyde or polystyrene or nylon, ceramic or vitreous materials such as baked clay, fibrous materials such as wood, or rubber. The strand may be dried by heating to enhance the electrostatic charge and/or counter the effect of antistatic dressings, without removal thereof, or humid conditions. The process may be effected on a modified spinning or twisting frame. As shown in Fig. 3, a filamentary strand 13 from a package 10 passes through a tensioning means 14 and an "electrifying assembly" 16 comprising rotating blades 28 and 30 which frictionally engage the filaments in a manner tending to oppose their travel and induce the electrostatic charge which, in combination with the alternate tensioning and relaxing action of the blades, spread the filament into a flat ribbon which passes around the top roller and between the nip of front rollers 38 of a drafting frame 32 whereat it is forcibly merged with drafted staple fibre material 53, i.e sliver or roving, which has been fed through the back and intermediate rollers 34 and 36, and is taken up by spinning or twisting means 42. As shown in Figs. 3 and 4, the strand 63 passes through tensioning means 64 and a slotted drying tube 70 to which air heated by an electrical element 78 is supplied via a header pipe 68 from a fan 66, thence to an "electrifying assembly" 88 which comprises a single rotating chargeinducing blade 94 frictional engagement of the filaments with which is interrupted by rotation of a screen 96 into the position shown in broken lines, Fig. 4, so that the separation of the filaments occurs only at spaced portions of the strand: the strand passes around the top roller and through the nip of front rollers 104 of a drawing frame 98 whereat the separated portions are forcibly merged with portions of staple fibre which have been drafted and then detached from an incoming supply of sliver or roving 118 by intermittent operation at random intervals of back and intermediate rollers 100 and 102, and taken up on spinning or twisting means 134. The synchronized movements of the shield 96 and the operation of the drive to rollers 100, 102, are effected by means of a source 158 of electrical impulses which energize a motor 122 (through an electronic time delay 176) and a solenoid 162 movement of a core 164 of which, against the restorative effect of a spring 168 rotates a cylindrical member 170 (around which a flexible cord 166 is wound) which in turn rotates the shield 96.