Verfahren und Vorrichtung zum Spritzgiessen

摘要

1358589 Injection moulding G A R PATFOORT 23 June 1971 [8 July 1970 15 April 1971] 29360/71 Heading B5A Granular material, compressed in an elongated zone 10 between a screw 3 and a cylinder 11 without plasticizing the material, and plasticized in a zone 4 between the end of the screw and the adjacent inner end face of the cylinder, is injected, e.g. through a non-return valve, into a mould by the pressure generated in the zone 10. Backftow of material in zone 10 is reduced by the material not being plasticized, and by the cylinder having grooves 12 or a portion 14 able to rotate with the screw to reduce slippage on the cylinder walls. The portion 14 may be rotated counter to the screw 3 and the grooves 12 may have parts adjustable in depth by the camming action of a collar 15 on movable parts of portion 14 as collar 15 is rotated on thread 16. The tip of the screw is insulated and the zones 4 and 10 are heated and cooled respectively to control the position at which plasticization occurs.