Cavity transfer mixing extruder

A cavity transfer mixing extruder which includes an extrusion unit and a mixing unit, which are united coaxially. The extrusion unit includes a barrel provided with a feed opening through which materials are fed into the barrel, and a screw shaft coaxially and rotatably extended through the barrel. The mixing unit includes a housing, a stator fixedly fitted in the housing and a first cavity group including circumferential cavity rows of cavities in the inner circumference thereof, and rotor joined coaxially to the front end of the screw shaft, coaxially rotatably extended through the stator, and provided with a second cavity group including circumferential cavity rows of cavities in the outer circumference thereof. The respective cavities of the first and second cavity groups, when developed on a plane, each has a parallelogrammic shape defined by a pair of opposite, parallel straight walls extending perpendicularly to the axial direction, and a pair of opposite, parallel straight walls inclined at an angle to the axial direction. The longitudinal axes of the cavities of the first cavity group, and the longitudinal axes of the cavities of the second cavity group are inclined in opposite directions, respectively, with respect to the axial direction so that the materials filling the cavities are forced forward as the rotor is rotated relative to the stator.