Patent GB-1508271-A (GB)
Title: Method and apparatus for producing a weft web sheet
IPC: D04H3/04
Filed: 1976-01-28
Abstract: 1508271 Finishing fabric edges POLYMER PROCESSING RESEARCH INSTITUTE Ltd and SEKISUI KAGAKU KOGYO KK 28 Jan 1976 [28 Jan 1975] 3357/76 Headings D1R and D1S [Also in Division B5] A weft web sheet is formed by longitudinally moving in a first plane two parallel continuous selvedge strips 6, 6' at a distance apart equal to the desired width of the sheet. simultaneously moving spaced web portions 1 cut to a length equal to the desired width of the sheet, in a direction transverse to the direction of movement of the strips 6. 6' and in a second plane parallel to the first plane. and, when the leading and trailing ends of the leading portion 1 align with the strips 6, 6', moving the two planes together and causing these ends to adhere to the strips 6, 6'.  As shown, belts 3. 3'. preferably of polyurethane. are heated by electricity fed through slip rings attached to shafts 4. 4' of their guide pulleys 5. 5'. The belts 3. 3' are spaced apart by a length equal to that of each cut portion 1 and have an outer coating of a hot-melt adhesive, e.g. an ethylene-vinyl acetate copolymer, maintained within a tacky temperature range. The selvedge strips 6, 6', e.g. each of a single yarn, a plurality of parallel yarns or a tape preferably with adhesive applied to both sides thereof, after passing over guide rollers 8 and a dancer roller 7, become adhered to the lower runs of the belts 3, 3' and, when the leading and trailing ends of a portion I fed by a lattice conveyor 2 register with the strips 6. 6'. beltpushing rollers 11, 11' on arms 10, 10' rotatable about shafts 9, 9' push down the belts 3, 3' into contact with the portion I so that the strips 6, 6' adhere thereto. The shafts 9, 9' are spaced apart by a distance equal to the width of the portion 1. As the shafts 9, 9' continue to rotate, the belts 3, 3' are allowed to rise so that the portion 1 is lifted by the strips 6, 6' from the conveyor 2 and conveyed in the warp direction of the finished sheet. Whilst the belts 3, 3' move by the width of the portion 1, the next portion 1 is carried between the strips 6, 6'. Cooling air is supplied through nozzles 12, 12' and the sheet is extended widthwise by means 13. The sheet passes over a rotating roller 14 and around a non-adhesive rubber roller 15 and bonding of the sheet without supplying an additional amount of adhesive may be effected by an electrically-heated arched plate 17 having projections thereon and rotatable about a shaft 16. Rotation of the shaft 16 is synchronised with that of the shafts 9, 9'. If a bonding adhesive is to be applied to the sheet, it may be applied to the projections of the plate 17 by a kiss roller (not shown). After passing over a guide roller 18 and between nip rollers 19, the sheet is wound on a core 20. The surface of the conveyor 2 may be coated with a buffering material to reduce distortion arising from the mutually perpendicular motion of the strips 6, 6' and the portion 1. Also, a small quantity of water may be applied to the conveyor surface so that its surface tension holds the portions 1. The conveyor 2 may be moved at a speed slightly higher than the speed of the web from which the portions 1 are to be cut so that, prior to cutting, this web is tensioned. In a modification, instead of electricallyheated pulleys 5, 5', steam drums are employed and the belts 3, 3' are guided by a comb 23. In addition to the strips 6. 6', reinforcing strips interspaced between the strips 6, 6' may be applied. In an Example, the portions 1 are cut from a web formed by longitudinally slitting a cylinder of parallel longitudinal glass fibre yarns, the yarns having been bonded by an ethylene-vinyl acetate copolymer adhesive ejected by a high speed rotating vessel onto the inside of the cylinder. Parallel glass fibre yarns coated with hot melt adhesive are used as the selvedge strips.