摘要 |
1351760 Injection moulding hollow articles ESSO RESEARCH & ENG CO 15 Oct 1971 [13 Nov 1970] 54163/70 Heading B5A Hollow cross-linked elastomeric articles, e.g. tyres, inner tubes, balls and hot water bottles are made by injection moulding the two halves of the article in a mould assembly comprising a core 4 positioned between two mould members 1, 2, opening the mould assembly and removing the core, leaving the mouldings in the mould members, closing the mould members so as to join the two halves of the article, consolidating the joint by pressurizing the interior of the hollow article, and keeping the mould closed until cross-linking is effected. In the example shown an inner tube is made in two halves in the mould assembly 1, 4, 2 by injecting from air injector 7 through passages 12, 13. The mould member 2 is stationary and provided with connections 34, 35 for cooling and heating purposes, and with an air inlet 14. The core 4 has connections 40, 41 for heating and cooling. The core is connected by tie bars 42 to an assembly for moving it horizontally and vertically, the resulting movement being indicated by arrow 39. The core 4 may be made up of four sections 47 ... 50 connected by bolts 51, 52 (Fig. 3). The lower part of Fig. 3 shows heating elements 58, 59. |