| 摘要 |
852,767. Moulding boats. UNITED STATES RUBBER CO. Jan. 30, 1959 [March 20, 1958], No. 3361/59. Class 87(2). [Also in Groups VIII and XXXIII] A boat hull is moulded from a plastic laminate 10 having an expanded cellular core 11 disposed between and integral with low-expandable outer structural sheets 12, 13, 14 and 15. The plastic for the core 11 and sheets 12 and 13 is made from a blend of a major proportion of thermoplastic resin (e.g. styrene-acrylonitrile) and a minor proportion of a rubbery material (e.g. butadiene-acrylonitrile) and a vulcanizing agent (e.g. sulphur). The core 11 composition further includes a blowing agent. The sheets 14 and 15 are made from an elastomeric material (e.g. equal parts of chlorosulphated polyethylene and butadiene-acrylonitrile rubber). The laminate 10 is heated under pressure causing the core 11 and outer sheets 12, 13, 14 and 15 to bond together, the rubbery constituents to vulcanize and the blowing agent to be decomposed and expands the core 11. The expanded laminate 10 is then secured at its periphery to a frame and is further treated so that it can be shaped by the mould 34, adapted to be lowered by the hydraulic cylinder 35 and provided with holes 36 which communicate with a source of vacuum via the flexible connections 37. The laminate may have further layers on its outer surfaces consisting of a substantially saturated elastomer (e.g. chlorosulphated polyethylene). |
