Process, for removing tubular moulding from an injection mould, comprises rotating a core with circumferential projections to expand the hollow moulding

摘要

A process for removing a tubular plastic hollow member (1) with a cut back section (5) from an injection moulding unit, comprises rotating a core (7) with projections (8) on its outer circumference, inside the hollow member. The hollow member is expanded over the projection area so the core can be withdrawn. Only the core is rotated, and the core has a primary cylindrical element which can be moved along its longitudinal axis, and a secondary cylindrical element. The radial projection length corresponds to the depth of the cut back section in the hollow member. The projections are chamfered in the rotational direction. The primary element has outer wall holding ribs (15) and the diameter in this area is no larger than the smallest inner diameter of the hollow member. The hollow member consists of polypropylene.