| 摘要 |
In order to provide a process for the injection moulding of parts made of synthetic thermoplastic material, whereby thermoplast is injected under pressure into a mould consisting of two halves and to compensate for the shrinkage caused by curing further thermoplast is supplied, by means of which it is particularly easy and possible with simple structural means to form plastic parts with closed internal spaces, it is proposed that, to form a hollow in a region (5) of the plastic part, the mould (1) surrounding this region is enlarged by moving a part of the wall (3) during the post-pressure stage and injecting gas under high pressure into the thermoplastic material therein which is doughy at least in the core so that the skin (6) of the thermoplast close to the moved wall region and already cured is pressed against the moved wall region (3) with the simultaneous formation of a hollow space and the doughy core part of this region binds the separating seams between the moulded plastic part in this region and the partial region of the thermoplast pushed towards the moved wall region.
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