摘要 |
A process of producing an injection moulding of plastics material comprises introducing the plastics material in the form of a molten stream into a mould space, and at one or more selected positions injecting a predetermined, finite quantity of a non-plastics fluid under pressure into the stream of plastics material at a controlled rate, the fluid being injected through means (19;90) around which flows the stream of plactics material whereby the fluid is injected directly into the plastics material, the fluid thereafter flowing simultaneously with the plastics material between the mould surfaces to fill the mould space (12) and exerting a pneumatic pressure on the surrounding plastics material (8) to pressurise the plastics material outwardly towards the mould surfaces. <??>The invention further provides an apparatus for producing an injection moulding in accordance with the process, and an injection moulding produced thereby. |