Patent GB-1236011-A (GB)
Title: Improvements in or relating to weaving
Inventor: HUSSEY ROY JOHN
IPC: D03D15/00
Filed: 1967-03-07
Abstract: 1,236,011. Film fibrillation. CREATORS Ltd. 7 June, 1968 [7 March, 1967; 3 Nov. 1967], Nos. 10749/67 and 50210/67. Heading B5B. [Also in Division D1] Film is fibrillated by a method comprising providing a roll of a wide web of longitudinally orientated film of thermoplastic material, and slitting or splitting said wide web of film as it is unwound from said roll into strands of a desired denier. Such strands may at the same time be fed directly to the weaving frame of a loom to form the warp strands of a fabric being woven. Preferably, the film is polypropylene, orientated to a degree of from 5:1 to 9À5:1, especially from 8:1 to 9À5:1, although other polyolefins are mentioned. In apparatus as shown, the roll of film 11 is made by extruding the thermoplastic material in the form of a wide web of film 2 (e.g. 22 inches wide), cooling the film as it is being extruded by passage around chill rolls 3, against which it is pressed by an air knife indicated by arrow 4, passing it around rollers 5 and first godet unit 6, through which the film is advanced at a predetermined speed, and then through an orientation oven 7 in which it is heated to, e.g. 154 C. to a second godet unit 8 through which the film is fed at a considerably higher predetermined speed. The film next passes through an annealing oven 9, where it is heated to a temperature lower than that of the orientation oven, e.g. 110 C., to a third godet unit 10, through which it is advanced at a speed slightly less than that through the second godet unit, and is finally wound up on roll 11. To ensure that the oriented film wound up at 11 is flat, with no transverse rippling, a plurality of transversemembers 12, e.g. cylindrical rollers, are disposed in the orientation oven 7 and extend across the width of the web, being arranged one after the other in the direction of movement of the web and alternately bearing on opposite surfaces of the film so as to cause the film to travel along a wavy path. The rollers are suitably located at a region in the oven where the principal stretching occurs. In weaving, the unslit web of orientated thermoplastic film, made as above, is fed from roll 14 via a tensioning device 15, to a slitting unit 16 which slits the film into warp strands 17. The strands pass directly to the weaving frame 18 where the fabric is woven, and the web of woven fabric 19 so made is wound up on reel 20. Tensioning device 15 comprises a swivelling drum 21 having four rollers 22 around which the film 13 travels in succession. Where a plurality of unslit films are used, a separate tensioning device may be used with each roll. Slitting unit 16 comprises a plurality of slitting blades 23 disposed across the width of the web, and projecting upwardly from support member 24, on to which the film is led over the combined edges 25, being held in place by pad 26. Strands 17 so formed are held in contact with 24 at its front edge and are prevented from moving vertically in response to the loom operation by a guide member 27. As reel 20 takes up the woven fabric produced by the weaving operation, it advances the film from roll 14 through tensioning device 15 and slitting unit 16 so as to continuously produce the warp strands for the weaving.