Injection machine for molding plastics or metals has a screw plasticizing unit which moves axially in the injection piston

摘要

A screw plasticizing unit(18) moves along the machine axis and supplies melt via a channel(16) with a shut-off valve(17) to a chamber(14) in front of an injection piston(15) moving in a housing(13). In one form of the machine the screw plasticizing unit moves inside the injection piston and a further melt storage chamber(22) with variable volume is created between the piston and plasticizing screw. An Independent claim is made for a method of operating the claimed machine in which, during injection, the plasticizing screw continues to operate at the plasticizing speed or lower. Preferred Features: In a second form of the machine the rear end of the injection piston forms a cylinder around the plasticizing screw which moves axially in the cylinder. An additional variable volume melt storage chamber is again between injection piston and plasticizing screw.