| 摘要 |
1510579 Forming nets POLYMER PROCESSING RESEARCH INSTITUTE Ltd and SEKISUI KAGAKU KOGYO KK 27 July 1976 [5 April 1976] 31214/76 Addition to 1508271 Heading D1R [Also in Divisions B5 and B6] A method of forming a bonded non-woven net or laminate from warp and weft "webs" comprises moving in a first plane a continuous warp material 3 and/or 5, simultaneously moving weft webs 15 cut to a length equal to the width of the warp material in a direction transverse to that of the warp material and in a second plane parallel to the first; and when the front and rear ends of a weft web 15 are aligned with the sides of the warp material bringing the weft web and the warp material into contact and causing them to at least temporarily adhere to each other to form a continuous band of weft webs secured onto the continuous warp material, the weft webs being subsequently bonded to the warp material and/or a warp web. The webs may comprise a parallel array of staple fibre yarns, mono or multifilament yarns, rovings, flat yarns, stretched tapes or split yarns, of glass, carbon, nylon, polyethylene or polyester, optionally bonded with a hot melt, solution or dispersion of an adhesive, or autogeneously with transverse filaments of e.g. ethylene-vinyl acetate copolymer or fibres formed by centrifugal ejection and deposited on the array as described in Specification 1464785; or a fibrillated film. The warp material is pressed down into contact with the weft web 15 by rollers or bars 18, 18' rotated around shafts 16, 16' by arms 17, 17'. The shafts are driven by eccentric gears or links so that their angular velocity is greatest when the warp material is pressed against weft web 15. The continuous weft web is fed on lattice conveyor 14 and cut at intervals, the conveyor speed being greater than the web feed rate so as to produce intervals between the cut webs. In one embodiment the warp material comprises a warp web 3 to which is applied a liquid which wets the web and enables it to pick up the weft web. The liquid may be water, or an 0.01 to 0.2% aqueous solution of polyethylene oxide or polyvinyl alcohol or a aqueous emulsion of an adhesive polymer and applied by roll 12, or a hot melt adhesive. Preferably the warp web 3 is backed up by belt 5, which may take the form of two spaced belts aligned with the selvedges of web 3. A second weft web 20 may be applied to sandwich the weft web. Instead of web 20 an array of threads for pressing the weft webs 15 on warp web 3 may circulate between guide roller 22 and a drying means where they are peeled off the two layer laminate. Where the liquid applied by roll 12 does not contain permanent adhesive such adhesive can be applied by roll 2. In other embodiments the warp material comprises a lattice belt 5, e.g. a number of spaced parallel belts. Warp web 20 is pressed against the weft layer and the two layer laminate is stripped from belt(s) 5 by threads disposed on the belt or between the spaced belts. The separation between the spaced belts or the two selvedge belts is increased by comb 6 and decreased by comb 7 to spread the adhered weft webs and so avoid creasing. Where hot melt adhesive is used as the wetting liquid the rollers 4, 4' are heated. |
