Patent GB-621900-A (GB)
Title: Improvements relating to the preparation of fibrous materials for spinning
IPC: D01G15/96
Filed: 1946-07-15
Abstract: 621,900. Separating fibres. CLARK, D. M. (Forte Dupee Sawyer Co.). July 15, 1946, No. 21147. [Class 120 (iii)] A method of preparing cashmere and similar fleeces containing relatively coarse and fine fibres, comprises subjecting a web or film of such fibres; produced on a card or similar apparatus, to a dividing operation whereby the majority of the coarse fibres are divided into short lengths while the majority of the fine fibres are left of greater length. After scouring and carding, the fibres are fed in the form of a thin web or film 14 to a conveyer belt 15 passing over a roll 16. which feeds it to the bite between the rubber-covered roll 18 and the roll 20, which are driven at a greater surface speed than the, belt 15, and thus tend to parallelize the fibres. A rubbercovered roll 19 is driven at the same speed and in the same direction as the roll 18, which it contacts, thus tending to remove any fibres adhering to the latter, and return them to the roll 20. The web now passes to the bite between the rollers 20 and 21, where the coarser fibres are cut, the roll 21 being surrounded by a series of wires 47 which are wrapped spirally around it, and around pins 46 on collars 45 which are screwed on to its ends. which are threaded 'so that the wires can be tautened by rotating the collars 45. The bearing blocks 38 of roll 21 slide between the upright frame members 30, and the weight of the assembly is supported by springs 39. The height of the blocks 38 may be accurately adjusted by means of screws 41, the upper ends of which are threaded into blocks 44 carried by the frame cross-member 40, and the lower, reduced ends, which have 'threads of different pitch but of the same hand, into blocks 42 attached to the bearing blocks 38. A film of moisture is applied to the roll 20 to cause the fibres to adhere to it ; this may be done by having a reservoir 50 with a flexible felt-covered side 54 adjustably pressed against the roll, or by spraying either the roll or the fibres. After cutting, the fibres are drawn off into metal conduits 60 connected with the fan housings 61, a driven rubber-covered roller 22 detaching any remaining fibres. The fibres are then blown into a series of tubes 70, 71, 72, 73, 74, 75, 76, 77, which are interconnected at right angles, there being dead spaces beyond the interconnections, in which the short fibres accumulate, and are drawn off through caps 100 and pipes 102 which are periodically connected with pipes 85 by rotating disc-valves 81. The remaining fibres are carried into a chamber 90, where they are entrained by rotating wire gauze discs 91, from which they are removed by scrapers and collected. Alternatively, the cut fibres may be separated by the following:- (1) A rotating clothed cylinder with a second clothed cylinder rotating in the opposite direction and at a faster speed, with the teeth of the clothing engaging the backs of the teeth of the clothing of the first cylinder, so that it strips the web carried by the latter, the shorter fibres falling out at the point of transfer. A rotary brush may be substituted for the second cylinder. (2) Two brushes, rotated.in the.same direction, one having stiffer bristles and being rotated faster than the other, and removing the web in a downward direction as it is carried upwards by the other brush. (3) A cylinder provided with card clothing, against which a rotary brush or brushes rotate, to brush out the shorter fibres. '(4) A pair of workers and strippers mounted beneath a card cylinder. (5) A clothed main cylinder and a clothed doffer cylinder, the former being driven at a high surface speed relative to the latter. (6) A doffer cylinder with a reciprocating comb acting against the backs of the teeth of the clothing. (7) A clothed cylinder with a number of beaters consisting of relatively small cylinders provided with helically-arranged ribs, which are arranged to rotate against the teeth of the clothing in the direction of their points.. ,