GB1370734A - Method of laminating uniaxially stretched layer material - Google Patents

Abstract

1370734 Oriented laminates POLYMER PROCESSING RESEARCH INSTITUTE Ltd and KOBE STEEL Ltd 19 Jan 1972 [19 Jan 1971] 2515/72 Heading B5N Warps and wefts of uniaxially oriented material (defined below) are cross-laminated by (i) depositing lengths of weft 6, 6<SP>1</SP> successively at constant speed on to an endless belt 1 moving at a higher speed than the weft supply means and sucking the wefts on to the belt whereby they are subjected to frictional rubbing and are spaced apart on the belt owing to the speed differential, (ii) transferring the wefts 6, 6<SP>1</SP> to overlie an air-permeable travelling warp layer 21, and (iii), when each weft and the warp register, releasing the weft from the belt, successive wefts being laid on the warp to form a continuous layer. The weft lengths 6, 6<SP>1</SP> are, as shown, formed by extending an oriented web 7 to a desired width, without affecting the orientation in a suction channel 9, passing the web 7 over resistance rods 11 and through latticework gripping belts 12, 13, and cutting it by a heated rod 20 in the belt 13. The suction may be exerted via a chamber 3. The wefts 6, 6<SP>1</SP> may be deposited on to the warp 21 by bringing perforations in plates 22, 23 into register whereby suction is exerted from a chamber 24; if necessary means are provided to overcome the suction of chamber 3. Alternatively, the deposition may be achieved electrostatically by means of plates spanning the warp and weft, the lower half of chamber 3 being dispensed with. Successive wefts 6, 6<SP>1</SP> may be so deposited so to overlap. After deposition, the assembly may be treated with a binder (if not already present), dried and and subjected to heat and pressure. The warp and wefts may be laminated at any convenient angle. The term "uniaxially oriented material" comprises (a) webs obtained by splitting a uniaxially oriented plastics film and extending it to a desired width (as shown), (b) webs formed by binding a series of uniaxially oriented plastics strips or tapes in spaced or contacting relationship by means of film or fibrous binder and (c) uniaxially stretched plastics film. In examples, polyethylene split-fibre webs are bonded by means of pre-applied ethylene-vinyl acetate copolymer emulsion to form a product for reinforcing paper, polyethylene and non-woven fabrics, and polyethylene tape webs are bonded by means of a polyethylene binder film to form impermeable or latticed products.