Twin screws - extruder, a method for directly extruding with this extruder and a method for the production of pet - products

摘要

PROBLEM TO BE SOLVED: To reduce to a large extent the lowering rate of IV of a material to be kneaded compared with the conventional lowering rate without the necessity of an expensive vacuum device when the material to be kneaded is dried and kneaded and extruded continuously without the predrying of a raw material and the after-treatment of kneaded resin. SOLUTION: In a biaxial kneading extruder in which a pair of screws 5, left and right, for feeding the material to be kneaded to the discharge opening 3 side on the downstream side are inserted rotatably into a cylinder 4 provided with a feed opening 3 and the discharge opening 3 for a material to be kneaded, and an internal space of the cylinder 4 positioned on the downstream side of a kneading section 10 is provided in the middle of the screw 5 as a vacuum zone VZ for removing the water content from the material to be kneaded, the length of the screen 5 in the vacuum zone VZ is set as ten times or more as long as the cylinder inner diameter D.