Patent GB-1422574-A (GB)
Title: Production of hollow moulded articles
IPC: B29C49/06
Filed: 1973-01-26
Abstract: 1422574 Injection-blow-moulding NISSEI PLASTICS INDUSTRIAL CO Ltd and SHOWA DENKO KK 26 Jan 1973 [29 Jan 1972 (2)] 4120/73 Heading B5A In an injection-blow-moulding process, a parison is formed in an assembly of an injection mould, core and neck mould, the injection mould and core are removed therefrom and a stretching, and blowing rod is inserted into the parison being held by its neck mould and the parison is then reheated, stretched and blowmoulded. As shown in Figs. 2a, 3, perpendicular sections, the apparatus comprises four stations: injection A, cooling B, reheating C and stretching and blowing, D, equally spaced around a turntable 4 supported by a main post 3 and connected to an upper rotatable member 5 by tie rods 6. Received in recesses around the turntable periphery are neck moulds 7 supported by plates 12. At the injection station A, injection mould 33 engages injection cylinder 28 to inject material around core 34, which is mounted on platen 32 which is vertically reciprocable on guide rods 29a by piston-rod 31 of cylinder 30. Also at this station, the stretching/blowing device 10 which is connected by stays 16a to a coupling 22 is vertically reciprocable by cylinder 21, coupling 24 of which slidably engages the coupling 22. A transfer device 36 is rotatable on shaft 41 by rack 44 and pinion 43, and vertically reciprocable by means of an extension of platen 32 engaging collar 42 on shaft 40 integral with device 36, with carrier plates 12 and neck moulds 7 engaged therewith by means of piston-rods (38a, 39a, Fig. 2b, not shown) of cylinders (38, 39). Device 10 comprises a blowing head block 9 having a nozzle (9a, Fig. 4, not shown) through which passes a stretching rod 8 defining an air passage (15) connecting with a passage (15a, not shown) in plate 16. At reheating station C, a heating mantle 47 is vertically reciprocable on table 52 by cylinder 50 to surround parison P. At station D, blow mould halves 56 on table 61 are opened and closed by cylinders 53, mould bottom 59 is vertically reciprocable by cylinder 60, air supply nozzle 66 is connectable with passage (15a) and stretching rod 8 is lowerable by sliding engagement of its head 8a in coupling 26 of cylinder 25. Neck mould parts 7a are spring urged to the closed position by springs (19, Figs. 10, 11, not shown) but notches (20) therein are engaged by spring-loaded members (57) in the blow mould parts 56 so as to open the neck mould and blow mould together. In operation, turntable 4 is rotated intermittently by motor 62 and crank 63, precise location being effected by pin 65. In each position of the turntable, a parison P is injection moulded while the blow-mould is closed on a reheated parison (Fig. 5, not shown); then, as the injection assembly is opened, a cooled parison is reheated and a reheated parison stretched (Fig. 6, not shown); the newly injected parison is then transferred to the turntable at A while heating continues at C and blow-moulding is effected at D (Fig. 7, not shown); finally, device 10 is lowered at A, heater 47 is removed at C and the blow mould assembly opened at D and the article removed. Table 4 is then indexed for a similar sequence in its next position. Rod 8 may be heated.