RAW MATERIAL FEEDING MECHANISM FOR MOLDING MACHINE

PROBLEM TO BE SOLVED: To suppress an unfavorable biting of a raw material comprising ground pieces of plastic wastes. SOLUTION: The lower part of a hopper and a screw insertion hole 2 of a heating cylinder are vertically communicated by a first raw material passage 12 which is formed on a sleeve member 9, and a second raw material passage 13, and a raw material in the hopper is fed in the screw insertion hole 2 by a natural dropping; For the internal surface of the first raw material passage 12, the cross section is circular, and the internal surface is a slope wherein the radii of respective cross sections in the vertical direction linearly reduce downward. That is, the internal surface is a truncated conical surface. Thus, an unfavorable biting in the first raw material passage 12 can be suppressed, and the raw material feeding into the screw insertion hole 2 is smoothly performed. Also, the sleeve member 9 is detachably fitted in a first fitting hole 10 and a second fitting hole 11 of a heating cylinder housing 4, and by replacing the sleeve member 9, the first raw material passage 12 in response to the kind or the like of raw materials can be set.