Patent ID: 6063315
Filing Date: 2000-05-16
Classification: B29C,B29L,B62D,Y10T

Abstract:
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.