Patent ID: 6379143
Filing Date: 2002-04-30
Classification: B29C,B29L

Abstract:
An injection molding apparatus for molding a plastic article having a frame by fitting an upper mold and a lower mold by pressing, and injecting molten resin through a gate, wherein the improvement comprises:(a) a net groove formed in stripes by a plurality of first grooves extended only in one direction in the upper mold, and a plurality of second grooves extended only in the said one direction in the lower mold, ones of the first grooves in the upper mold and the second grooves in the lower mold being faced with each other and extending in substantially the same direction relative to one another, ones of said first and second grooves having first and second respective ends; (b) at least one passage groove having a larger diameter width relative to the first grooves and the second grooves for facilitating the fluidity of the molten resin, one or more of the passage grooves intersecting the first grooves and the second grooves being formed on the first grooves of the upper mold and/or the second grooves of the lower mold; (c) at least one gate formed on the passage groove for injecting the molten resin into the mold; and (d) a frame groove formed to surround the first and second ends of the first grooves in the upper mold and/or the first and second ends of second grooves in the lower mold.