Plasticizing sections of cold feed rubber extruders

摘要

A Transfermix cold feed extruder having a plasticizing section that includes a plurality of screw flights therein in a transfer zone that is formed over a common length of the screw and barrel of the extruder. In the transfer zone, a helical groove in the screw varies in cross section from a full area to a zero area, and a helical groove of opposite hand in the barrel correspondingly varies in cross section from a zero area to a full area. The extruder is provided with a set of flow deflectors in a cut in the screw positioned immediately upstream of the plasticizing section. By the coaction of the flow deflectors with the plurality of screw flights, an increase of throughput for difficult-to- extrude compounds, with an improvement in the quality of the extrudate, is obtained in a surprising manner.