BARREL PROCESSOR HAVING DEGASSING MEANS

摘要

A processor (1) for a molten polymer composition comprises at least one screw (10) rotatably arranged within an enclosure (11) having an inner wall (12) fitting the at least one screw in a portion, at least, of the enclosure; the processor comprises at least one chamber (14) for degassing said molten polymer comprising at least one piston (141) for reciprocating movement between a first (FP) and a second (SP) position; the piston has a front face (143) shaped in conformity with the inner wall of the enclosure in the fitting portion thereof; the front face of the piston forms part of the inner wall in the fitting portion of the enclosure when the piston is in the first position (FP) and pro­vides an opening (121) of the inner wall when in the second position (SP); the piston opens a passage (144) for connecting the opening of the wall with a degassing outlet (16) when in the second position (SP); chamber (14) has an inlet (17) provided with a valve (171) for permitting an intermittent passage of a stream of gas across front face (143) when the piston in second position (SP) so as to achieve gas scouring of the pis­ton's front face.