Patent GB-1484667-A (GB)
Title: Method and apparatus for manufacture of spun yarns
IPC: D02G3/40
Filed: 1973-09-19
Abstract: 1484667 Composite yarns BOBTEX CORP Ltd 9 Sept 1974 [19 Sept 1973] 43875/73 Headings DID D1F D1N and D1W To form a yarn, first individualised fibres in a non-coherent form are formed into a layer on a movable collecting surface, a further yarn forming material in the form of a carrier strand or an interfibre binding material is then placed on the layer, second individualised fibres are then placed on the first fibres and further yarn forming material, and the resulting composite material is transformed into unsolidated yarn. Preparing composite staple fibre material. Sliver, roving, polymer film, oriented polypropylene tape, fibre webs or bast fibres are fed by rolls 18, 20, Fig. 1 to two perforate needle rolls 30, 32 on rotating shaft 34. Suction chamber 42 assists the deposition of material on the rolls. Cutting means, e.g. knife blades, may be mounted on the rolls 30, 32 which may be rotated at a higher surface speed than rolls 18, 20. Fibres are transferred to two perforate lickerins 70, 72 rotating on shaft 76, by a gas jet from conduit 52. An air jet from conduit 84 lifts fibres from lickerin 70 into cavity 80 which deflects the fibres, Fig. 2, axially of the lickerin to lie on groove surfaces 90, 92 of a collecting roll rotating between, and possibly on the shaft of, the lickerins. Suction apertures 96 in surfaces 92 aid fibre deposition. Fibres from lickerin 72 are deflected by cavity 97 onto the fibres already on the collecting roll to form a composite yarn material on the roll. A roll 100, Fig. 1, presses on the fibres laid on the collecting roll, preferably before fibres from lickerin 72 are laid on the roll. A fibre binding material, e.g. a polymer, may be extruded, e.g. by extruder 120, onto the first fibres laid on the collecting roll. Lickerins 70, 72 may be rotated at different speeds. Yarn twisting.  Material is withdrawn from the collecting roll through a false twist spindle, and the twist in the strand of first laid fibres extends back to the nip between roll 100 and the collecting roll. The other laid fibres are more loosely twisted around the first laid fibres. These outer fibres are caused to project, by a device 300, Fig. 1, comprising an annular suction chamber or an electrostatic device. The resulting yarn has an inner strand twisted in one direction, and outer fibres twisted about the strand in the opposite direction. Alternatively, Fig. 2, the yarn may be twisted by rotating friction disc 130 engaging recess surface 134. To twist the outer fibres about the inner strand, a pneumatically rotated spindle 204, Fig. 5, may be rotated about the yarn rotated by disc 130. Spindle 204 may be located upstream or downstream of disc 130, and may rotate faster than the inner strand rotated by the disc. Second Embodiment.  Material is fed, Fig. 12, via lickerins 420, 452 to lie in the groove of collecting roll 436. An at least semi-molten fiber binder 468 from extruder 460 may be deposited on the first fibre layer on roll 436. Alternatively, carrier material 510 or 512 may be coated by the extruder. Only one source of fibre material may be used with the carrier, when the yarn may comprise an inner carrier, the binding material and an outer layer of fibrous material. The carrier may comprise multifilament strands, fibrillated tapes, a thermoplastic tube, or spun yarns of jute, sisal, flax, glass, asbestos, waste fibres or kraft paper. The carrier may be supplied uncoated, may be passed through cavity 522 to expand the carrier, and may be treated with an agent by roll 534. Composite material 474 running from roll 436 may be made tacky by heater 486 and further fibrous material 488 may be deposited, e.g. by pneumatic means, on strand 474.  Consolidating Composite Material. Strand 474 may simply be twisted by device 480, or an outer fibrous layer on the strand may be expanded by an air vortex in chamber 494 before twisting, or the strand may be consolidated by driven roll 508. Further, the strand may be passed through twister 500 including rotating, tubular spindle 504 having slots through which air is sucked to expand the outer fibre layers.