GB1324661A - Nonwoven fabrics and process for preparing same - Google Patents

Abstract

1324661 Laminates HERCULES Inc 22 July 1970 [22 July 1969 16 Dec 1969] 26379/70 Heading B5N [Also in Division D1] Two layers, each comprising substantially parallel synthetic thermoplastic filaments in spaced apart side-by-side relationship with adjacent filaments interconnected by a plurality of fibrils, are cross laid one upon the other with the filaments of one layer being disposed at an angle of from 20 degrees to 90 degrees to those of the other layer and the two layers being bonded together to form a net-like non-woven fabric. The filaments may be 1À5 to 20 denier polypropylene, polypropylene/ethylene copolymer, nylon, polyethylene terephthalate or polyacrylonitrile, they may be foamed or bicomponent (so as to crimp on heating) and are preferably produced by fibrillating plastics film, by passing the film over a triangular crosssection rotatable bar 6 having serrated edges 7, Fig. 2. In the embodiment of Fig. 4 the warp filaments are drawn from one or more supply beams 11 by pinch rolls 18 through annular former 12 on to stationary mandrel 13. Weft filaments 14 are laid on to the covered mandrel by the rotation of the carrier 16 of supply beams 15 at an angle of 20 to 89 degrees determined by the ratio of the speed of advance of the warp and weft filaments. The tubular fabric is compressed by pinch rolls 18 into a sandwich of inner warp filaments and outer weft filaments. The rolls 18 may be heated to cause bonding by fusion at the cross-over points, or the films fused by ultrasonic heating, or an emulsion, dispersion or solution of an adhesive sprayed on by nozzles 19 and cured by oven 20. In the embodiment of Fig. 6 (not shown) the method is modified in that (a) the warp films are drawn over an adhesive roll (30) placed before mandrel 13, which carries an inert, non-adherent coating, and (b) on leaving the mandrel the fabric tube is slit along one or both edges by a knife (31) placed ahead of pinch rolls 18, so that the warp filaments are overlaid by weft filaments on one side only. In the embodiment of Fig. 7 the warp filaments are drawn off supply beam 33 by pinch rolls 34 between a pair of continuous endless wire belts or cables 35, 351. The weft filaments are supplied by beams 36 which rotate around the warp and belts 35, 35<SP>1</SP>, and slit by knives adjacent to rolls 34 to remove them from the belts. Bonding is by heated pinch rolls 34 or by application of adhesive. In the embodiment of Fig. 8 (not shown) warp filaments (40) are fed from roll (41) by pinch rolls (42) on to a moving continuous belt (43) to calender rolls 44. Its advancement is periodically interrupted whilst a cross beam (45) is rolled across the warp at a 90 degree angle, a hot wire (46) severs the laid weft filaments, and the beam retracted.