Apparatus having extrusion and mixing zones

Claim 1

Apparatus for extruding and mixing of material comprising: a. an elongated housing having an axially extending passageway therein, an inlet opening adjacent one end of the housing for introduction of feed material into said passageway and a discharge nozzle adjacent the other end of the housing for discharge of the extruded and mixed material, b. an extrusion zone defined by an extrusion screw extending through the passageway from the inlet end thereof to termination at an intermediate point between the inlet opening and discharge nozzle, and the housing disposed about the extrusion screw, the housing about the extrusion screw being cylindrical for confining material to the screw for the extrusion thereof, for plasticization of a plastic composition in the extrusion zone, c. a mixing zone defined by mixing means within the passageway, said mixing means comprising a core member and a worm helix disposed about the core member extending from adjacent said termination of the extrusion screw to adjacent the discharge nozzle, for simultaneously mixing and advancing the material toward the discharge opening, d. said core member and worm helix being mounted in the housing for rotation independent of each other.