GB978672A - Improvements in blow moulding hollow plastic articles - Google Patents

Abstract

978,672. Blow moulding hollow articles. E. R. HOLLOWAY Ltd. Dec. 17, 1963 [Jan. 25, 1963], No. 3242/63. Heading B5A] In apparatus for injection - blowing hollow articles there is at least one pair of mandrels, one of which is located in an injection mould while the other is located in a blow mould, and after removal of the blown article the mandrels are transposed so that the parison formed on the mandrel in the injection mould is located in the blow mould and the mandrel from which the article has been removed is in the injection mould. The injection apparatus 1, Fig. 1, includes a hopper 2 and a nozzle 6. The mould section 12 is mounted on a fixed platen and the mould section 13 is mounted on a platen 10 movable by an hydraulic ram 11. Between the mould sections 12, 13 is a mandrel carriage 14 comprising two pairs of mandrels 15, Fig. 3, which extend downwardly from and communicate with passages in discs 24, each mounted on a shaft 23a which carries a pinion 23 meshing with racks on rods 19, Fig. 4, extending from the piston rod of a jack 17. In the operative positions the mould sections 12, 13 define four moulds 32, 33, 34, 35, Fig. 6, of which the two central ones 32, 33 constitute parison moulds and the outer ones 34, 35 blow moulds. The parison moulds 32, 33 receive material from the injection nozzle 6 to form parisons while the outer mandrels are located in the blow moulds 34, 35. The mould sections 12, 13 are separated and the jack 17 operated to rotate the discs 24 through 180 degrees so that parison loaded mandrels are located in the blow moulds and the other two mandrels are located in the parison moulds. The injection apparatus is again operated to form two more parisons while air is blown through the outer mandrels in the moulds 34, 35 which are subsequently cooled before the mould sections 12, 13 are separated. A pair of hydraulic rams 39 are then operated to actuated mechanical strippers 36, Fig. 3, which push the finished articles from the two outer mandrels before operation of the ram 17 to transpose the mandrels and repeat the cycle of operations. In another example, vertically separable mould sections are suggested.