Patent ID: 7490974
Filing Date: 2009-02-17
Classification: B29C

Abstract:
1. A screw extrusion press for processing thermoplastic and not reticulating polymers, with a conveying screw ( 1 ) in a cylinder, said conveying screw ( 1 ) having a conveying zone ( 7 ) and a mixing zone with a mixing ring ( 3 ) that extends from a bottom ( 10 ) of the screw to a wall ( 20 ) of the cylinder, said mixing ring ( 3 ) comprising passage holes ( 4 , 5 ), wherein a shear gap ( 9 ) is formed between an outer perimeter wall of the mixing ring ( 3 ) and the cylinder wall ( 20 ) and wherein at least one passage hole ( 4 , 5 ) extends from the bottom ( 10 ) of the screw or from the vicinity thereof and opens out, at least in part, in said shear gap ( 9 ), said at least one passage hole ( 4 , 5 ) being at least partially closed on an outflow side ( 12 ) of said mixing ring ( 3 ), thereby conveying and accelerating molten mass from the bottom ( 10 ) of the screw ( 1 ) to the cylinder wall ( 20 ) into said shear gap ( 9 ).