Non-return valve for an injection molding machine has mating surfaces at the screw tip and melt outlet pressed against each other to effect sealing

摘要

The plasticizing screw(2) has a tip(3) with a sealing surface(5) and the screw housing(6) a sealing surface(7) near the melt outlet channel(9). A force-producing mechanism acts on the screw to press the two sealing surfaces in contact with each other and prevent back flow of melt.