SCREW FOR MOLDING MACHINE, EXTRUSION MOLDING MACHINE AND INJECTION MOLDING MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a screw for a molding machine having a simple structure and capable of efficiently plasticizing and melting a raw material resin. SOLUTION: A screw 10 for a molding machine can feed a raw material resin introduced from a hopper on an upstream end side toward a downstream end while plasticizing and melting the same and is equipped with the flight absent portion 15 provided to a compression portion C between the upstream and downstream ends. In this case, the depth of the flight absent part 15 is gradually reduced from the upstream end toward the downstream end.