Throughput control for screw extruder - has variable depth grooves in housing near inlet zone

摘要

A plastics processing machine with a screw has a feed zone with adjustable depth grooves. The shape of the grooves can be altered as required. In embodiments, a single screw extruder has an inlet zone which is made as a separate replaceable unit attached by a flange. The bushing has longitudinal grooves whose depth is tailored to suit the required feed rate for the material which is being processed. USE/ADVANTAGE - The invention is a simple method of controlling the extruder feed rate in injection moulding machines.