Recovery of raw material in extrusion uses extruder with start-up valve, extrudate being fed into store tank during start-up and fed back, without further processing, into extruder when process is stable

摘要

Method for recovering raw material in an extrusion process uses an extruder (1) fitted with a start-up valve (4). Extrudate is fed into a store tank (13) during the start-up phase and when the process is stable is fed back, without further processing, into the extruder. An Independent claim is included for apparatus for carrying out the method with a start-up valve which feeds extrudate into the tank when in one position and feeds it from the tank back into the extruder when extrusion is stable.