INJECTION MOULDING MACHINE WITH A CHARGING CYLINDER

摘要

A method in injection moulding wherein the plastic material is being screw plasticized and piston injected and wherein the plasticized plastic material is supplied to the piston injection cylinder (18) during the return of the injection piston (19). The plasticizing screw (12) is rotating continuously in a fixed axial position in the plasticizing cylinder (10) the pressurized plastic material being temporarily stored in a pressurized space (26) during the operating stroke of the injection piston in order to be supplied during the return of the injection piston from said space to the injection cylinder together with plasticized plastic material supplied directly from the plasticizing screw (12) to the injection cylinder. An injection moulding machine for working the method comprises a screw plasticizing cylinder (10) and a piston injection cylinder (18) connected to the outlet of the screw plasticizing cylinder via a non-return valve. A charging cylinder (26) having a pressurized piston (27) is connected directly to the outlet of the plasticizing cylinder, said charging cylinder communicating also with the piston injection cylinder via the non-return valve.