Cyclical injection molding method of injection molding method and system, as well as hollow plastic product of wall thickness control method and a hollow plastic products of plastic products

摘要

In a system and method for injection molding a hollow, plastic product having an end wall and a cylindrical side wall (30), a protractable and retractable contact element (20) of a core section (12) of the mold cavity (24) is protracted to a forward position so that its contact surface (22) contacts at least a significant part of the fringe region of the end-wall-defining portion of the cavity section (10), to thereby reduce the mold cavity area as projected on a plane perpendicular to the mold opening direction, and thus reduce the clamping force required. The dimensions of a plastic product are controlled during injection of a first quantity of plastic material by means of contact between a non-perpendicular contact surface and during an injection of a second quantity of plastic material by means of at-least-partly-solidified wall sections.