Screw for extruder, bearing segment used in the same and twin screw extruder provided with screw for extruder

摘要

In a screw for extruder, a bearing segment having a function of supporting a screw main body at an intermediate part when kneading is performed is provided at a position corresponding to a kneading portion or on the downstream side of the kneading portion. The bearing segment is provided with at least two flights having a sectional shape of a complete meshing type with one streak in the axial direction, the flights are arranged in the rotational direction with uniformly displacing a phase thereof respectively, and length of the flights in the axial direction is set to 0.2D (D: rotational outer diameter of the bearing segment) or more. According to the above configuration, bending of the screw main body is prevented and abrasion of the flights and a barrel is suppressed.