Patent attributes
A method for injection foaming molding of a thermoplastic resin includes the steps of (1) injecting the foaming-agent-containing plasticized resin from an injection apparatus 30 to fill a mold cavity 10a, (2) releasing a clamping force of a mold 10 immediately after the foaming-agent-containing plasticized resin is injected and filled into the mold cavity 10a, so as to release the pressure of the foaming-agent-containing plasticized resin in the mold cavity 10a, (3) maintaining the pressure-released state of the foaming-agent-containing plasticized resin in the mold cavity 10a for a predetermined period of time, (4) expanding the mold cavity 10a to foam the foaming-agent-containing plasticized resin, and (5) cooling and maintaining the foaming-agent-containing plasticized resin while the mold cavity 10a is in the expanded state.
