GB1381301A - Moulding threedimensional products - Google Patents

Abstract

1381301 Moulding thermoplastic tufts on to supporting webs J DOLEMAN 21 Jan 1972 [13 Jan 1971] 1569/71 Heading B5A [Also in Divisions A6 A4 and D1] Thermoplastic material 30 (Fig. 2) is fed into a plurality of mould cavities through a supporting web 1a, the material thereafter being shaped 31 by pressing members. As described for forming, matting, carpeting, turf, grass, a ski slope surface or a soil retention medium, cylindrical cups of petals 31 are attached to a supporting nylon, metal or fibreglass web 1a, which is precoated with a thermoplastic. The web 1a (Fig. 1) is fed between a drum 4 having rows of mould cavities 5, and a heated material supply block 3 having a row of nozzles 10, one for each cavity 5 of a row. Molten thermoplastic from a reservoir 12 is supplied at a controlled rate by trimming screws 14 into a cavity 13 and thence from the nozzles 10, through the web 1a, into a row of mould cavities 5. A water-cooled shoe 18 chills the thermoplastic filling the web spaces to seal the ends of the cavities 5. A row of forming punches 11 is reciprocated by a power press 6 to form the cups of petals 31 (Fig. 2). Upward movement of the punches 11 activates a pawl 7 to rotate a ratchet 8, gear-wheels 9, 9b and so index the drum 4 by one step. A rubber roller 19 and parabolic heater 20 bond a backing 16 to the web 1a, the petals are spread and interlocked by a plate 21, and the final matting &c. wound on to a reel 22. The drum 4 may be replaced by an endless conveyer supporting rows of mould cavities; the punches 11 are replaceable. The thermoplastic material comprises polyethylene, polypropylene, PVC, polyvinylidene chloride, polyvinyltetrafluoride, polyvinyl chlorotrifluoride, polyvinyl acetate, polyamides, segmented polyurethanes' polyurethane rubbers, silicone rubbers, natural and synthetic rubbers, or polyesters. Pigments and stabilizers may be added.