Patent GB-1320725-A (GB)
Title: Method and apparatus for producing thermoplastic synthetic resin  foamed articles
IPC: B29C33/34
Filed: 1970-08-28
Abstract: 1320725 Casting foamed plastics MITSUBISHI PETROCHEMICAL CO Ltd 28 Aug 1970 [29 Aug 1969] 41490/70 Heading B5A Thermoplastics foamed articles are cast in a metal mould having upper and lower parts by filling the lower part, placing and clamping the upper part thereon, passing the mould through a heater having a preheating, a melting and a foaming and cross-linking region and cooling the mould, removing the upper part and then the article therefrom. The apparatus comprises Fig. 1, a mould drying station 2, station 3 to release the upper mould part clamping mechanism, station 4 for upper mould part removal, preparing station 5 for removal of the mould core and formed article, mould cleaning, repositioning of the core and a reinforcing frame and for coating the lower mould part with release agent, filling station 6, stations 7, 8 for replacing and reclamping the upper mould part respectively, conveyer 10, heating station 12, and cooling station 14 via direction changing stations 1, 9, 11, 13. Between its removal and replacement, the upper mould part is conveyed along section 15. The mould core, Fig. 25, comprises two frames 177 carrying mating core sections 180, the frames 177 being clamped to the lower mould part 18 by pivoted clamps, 179, Fig. 17. Frames 177 also carry hooks 35. Heating station, 12, Fig. 5, comprises a main body 61 and a device 66 for producing hot air, which is fed via ducts 67, 68, blower 70 and ducts 71, 78, 79, 80 and 81 to blowing/suction mechanisms 82, 83 which direct the hot air on to the moulds 19 and suck it back for recycling or heat exchange to maintain the different temperature zones formed by the three circulation systems 106 (107, 108, Fig. 4, not shown), respectively. Each mechanism 82, 83 has air inlet and outlet holes (92, 91, Figs. 6, 7, not shown) and adjustable baffles (99). Direction-changing mechanisms, Figs. 9-11 (not shown), e.g. at station 1 comprises chain conveyer (122) and rolls (128, 133, 134) which feed the mould 19 until it engages stops (139, 140), position control mechanisms (137, 138) and chain conveyers (129). Stops (139, 140) are pushed back by the mould until they engage limit switches (149) to shut off motion of rolls (133) or (134) to straighten the mould, a guide groove on the underside of which engages projection (124), and the mould is then advanced by conveyers (129) over rolls (125). Upper mould part clamping device, Figs. 12- 16 (not shown) at stations 3, 8 comprises a vertically reciprocable plate (56) carrying casings (160) from each of which depends an air-driven rotary shaft (161). The upper mould part (17) has an inclined clamp plate (168) through which extends post (169) from the lower mould part (18) and having a clamp handle (58) therethrough which is rotated to clamp or unclamp the upper mould part as desired by fingers (164) on the end of rotary shafts (161). Preparing station, 5, Figs. 17, 18 (19, not shown). Support members 36 are advanced by cylinders 30 and clamps 33 are engaged with core hooks 35 by cylinders 31, 32, the latter being pivoted at 188. Pivot clamps 179 are disengaged by vertically reciprocable members (197, Fig. 19, not shown) on the ends of supports 36 which are then retracted to withdraw cores 34. Vacuum pads 38 are then lowered to remove the article which is transferred to store 41, Fig. 1.