Injection molding process, mold for injection molding, and injection-molded article.

摘要

A means of injection-molding a thermoplastic resin so as to strengthen internal welds within a molded article produced therefrom in a mold cavity (4) with an internal shape which divides the injected resin into two or more streams which subsequently reunite and weld together within the cavity (4), characterized in that the cavity (4) has at least one resin reservoir (1) protruding therefrom adjacent to a region at which the streams reunite, the said reservoir (1) having a retractable piston (9) which can be either advanced towards the cavity (4) to force resin from the reservoir (1) into the cavity (4) or retracted to withdraw resin from the cavity (4) into the resin reservoir (1) and thereby to reinforce the weld by causing migration of the resin in the weld.