초록 ▼

Molding of relatively large articles such as automobile body parts by gas-assisted injection molding with sequential gating of injected thermoplastic resin into the mold cavity. Elongated ribs in the parts form gas channels and strengthening ribs for the parts. Structural parts are made by adhesivel

Molding of relatively large articles such as automobile body parts by gas-assisted injection molding with sequential gating of injected thermoplastic resin into the mold cavity. Elongated ribs in the parts form gas channels and strengthening ribs for the parts. Structural parts are made by adhesively joining two such parts made by gas-assisted injection molding through a combination of hollow ribs and joining flanges at sides of the parts.

대표청구항 ▼

[ What is claimed:] [1.] A method of molding a relatively large article in a mold cavity comprising the steps of:injecting molten thermoplastic resin into the mold cavity at a first location and flowing the thermoplastic resin from the first location to a second location spaced from the first locati

[ What is claimed:] [1.] A method of molding a relatively large article in a mold cavity comprising the steps of:injecting molten thermoplastic resin into the mold cavity at a first location and flowing the thermoplastic resin from the first location to a second location spaced from the first location;sensing the arrival of the molten thermoplastic resin at the second location;injecting molten thermoplastic resin into the mold cavity at the second location substantially simultaneously with the arrival of the molten thermoplastic resin from the first location at the second location;controlling the step of injecting the molten thermoplastic resin into the mold cavity at the second location in response to the sensed arrival of the thermoplastic resin at the second location;discontinuing the flow of molten thermoplastic resin to the first location;subsequent to the arrival of molten thermoplastic at the second location, injecting an inert gas under pressure into the molten thermoplastic resin in the mold cavity to assist in distributing the molten thermoplastic resin to the edges of the mold cavity;cooling the thermoplastic resin at least to a solid state;venting the gas from the mold cavity; andopening the mold and removing the thus-molded article from the mold cavity.