NON-WOVEN WEBS OF FILAMENTS OF SYNTHETIC HIGH MOLECULAR WEIGHT POLYMERS AND PROCESS FOR THE MANUFACTURE THEREOF

摘要

1363679 Non-woven fabrics; forming webs; crimping fibres LUTRAVIL SPINNVLIES GmbH & CO 2 Nov 1971 [3 Nov 1970] 50807/71 Headings D1F D1N and D1R A non-woven fabric comprises helically crimped filaments of synthetic polymer, the diameter of the helices being 1 to 10 mm and the direction of the turn alternating every 1 to 50 turns, preferably every 5 to 15 turns. The polymer may be polyethylene, chlorinated polyethylene, a copolymer of ethylene with propylene, 1-butene, vinyl chloride, vinyl acetate, tbutyl acrylate or t-butyl acrylate/acrylic acid, polypropylene, nylon 6, 6.6 or 6, 10, polyethylene terephthalate, polymerised #-hydroxydecanoic acid or 4-(#-hydroxyethoxy) benzoic acid or plasticised polyvinyl chloride (optionally containing vinyl acetate as comonomer). In a preferred embodiment the polymer is extruded through multiple spinnerets and the filaments cooled by air provided by blowing or suction. The cool air may be directed parallel to the filaments by a tube (11, Fig. 2d, not shown) situated in the centre of the spinneret, or between spinnerets. Alternatively the air stream may make an angle of 90‹ with the filaments, as shown, or an intermediate angle set by adjustable baffles (13, Fig. 2a, not shown). In these cases the bulk of the cooling air is deflected parallel to the filaments and effects a primary take up action. Air escapes through perforated tube 15 or is drawn through it by a suction chamber if the cooling air is sub-atmospheric, adjustable flaps 16 then being used to keep air out. The main take-up is provided by a one or two stage pneumatic unit 20, the distance between the stages being adjustable. The pneumatic jets (26, Fig. 3, not shown) make an angle of 5‹ to 30‹ with the filaments and supply cold or hot air or steam. Connecting piece 41 leads to crimping chamber 40, the length of which can be adjusted by screw thread (42, Fig. 3). The shape of chamber 40 leads to vortices which helically crimp the filaments. The filaments travel along flexible tubes 50, whose ends 51 simultaneously undergo a circular motion through their attachment to beam 52 and a lower frequency reciprocation in a direction transverse to that of conveyor 60. The filaments are thus laid in overlapping trochoidal paths. Suction may be applied at 61. The web may be bonded by needling and/or heat treatment or the application of an aqueous dispersion of a curable acrylate resin or of a powdered adhesive. In one embodiment a backing in the form of waffle foam was provided, in another the product was needle-punched to a layer of carpet material.