Free blend-type metal powder mixed resin molded body manufacturing method

A metal powder mixed resin molded body manufacturing method for manufacturing a metal powder mixed resin molded body comprising the steps of:

• kneading a molding material including a metal powder, a thermoplastic resin powder, and an additive agent and using injection molding,
• wherein molding is performed by an injection molding machine in which a molding screw is arranged,
• the molding screw rotates inside a cylinder of the injection molding machine, and includes a feeding portion, a compressing portion, and a metering portion that are continuously and integrally provided, the feeding portion and the compressing portion being constituted by an one-line spiral flight,
• the flight of the compressing portion includes a plurality of sub-flights that extend in a spiral manner in a screw axis direction, and the sub-flights each have a polygonal shape with rounded corner portions,
• the plurality of sub-flights are arranged such that the corner portions are shifted by a set angle in a circumferential direction about the screw axis, the sub-flights are formed such that distances between an inner surface of the cylinder and the corner portions are smallest and distances between the inner surface of the cylinder and central portions between the corner portions are largest, and
• the metering portion is provided with a plurality of blending/aligning portions each having gear-like protrusions and recesses in a circumferential direction about the screw axis.