| 摘要 |
<p>1370141 Blow-moulding layered articles E I VALYI 13 Sept 1971 [14 Sept 1970 21 Dec 1970] 42544/71 Heading B5A In a blow-moulding process, a preformed plastics sleeve is placed on a cone, an outer layer is moulded on the sleeve to form a composite parison which is blown in a blow-mould to form a composite article. In Fig. 2, a sleeve 1 is placed on a blow-core 5 and an outer layer 11 is formed thereon and fused thereto in an injection-mould 6 having a neck-ring 7. The bottom 3 of the sleeve 1 may be supported against the surface of the injection-mould cavity. The outer layer 11 and sleeve 1 are then blow-moulded in a blow-mould 12, Fig. 4, by fluid supplied through ducts 13 of core 5. The sleeve may be pre-formed by powder coating, casting or by vacuum-forming from a sheet and supplied to the blow-core from a stack thereof or from a continuous web, being reheated if necessary. The sleeve may be flame-treated, e.g. if polyethylene or laminated to assist adherence to the parison. The parison may be of polystyrene or polyethylene with a sleeve of polyvinylidene chloride, acrylonitrile or methacrylonitrile polymers, polyacetals, ionomer resins, polyallomers, polycarbonates, polypropylene, nylon &c. to provide gas barrier or solvent resistance properties or adherence to the parison. A suitable sleeve comprises laminations of polyethylene, polyvinyl chloride, polyvinylidene chloride and polystyrene, the parison being polystyrene. The core may be made of a soft metal, e.g. aluminium and electrically heated.</p> |
