Patent ID: 8062016
Filing Date: 2011-11-22
Classification: B29C

Abstract:
1. An apparatus for injection molding comprising: a cavity mold and a core mold that can be closed for injection molding and opened to remove a product of injection molding including an article comprising a sheet material and an injection molded body that is on an upper surface of the sheet material, wherein said cavity mold and said core mold include respective cavity surfaces and parting surfaces, said cavity surfaces define a molding cavity between said cavity mold and said core mold when said cavity mold and said core mold are closed, the molding cavity extends to a peripheral part at a peripheral edge of the molding cavity when said cavity mold and said core mold are closed, said cavity surface of said cavity mold adjoins said parting surface of said cavity mold at said peripheral edge of the molding cavity so that the sheet material includes a formed portion, which contacts and conforms to said cavity surface of said cavity mold, and a holding portion, which contacts, conforms to, and extends along said parting surface of said cavity mold, when the sheet material is located in the molding cavity, and said cavity surface of said core mold includes an edge surface that is located at said peripheral edge of the molding cavity and that is oblique to the upper surface of the sheet material on said parting surface of said cavity mold when said cavity mold and said core mold are closed; a fixing device for fixing the sheet material at a fixed location, interposed between said cavity mold and said core mold, when the sheet material is located in the molding cavity and said cavity mold and said core mold are closed; a groove or recess extending beyond and from said peripheral edge of the molding cavity, in said core mold, extending laterally with respect to said peripheral edge of the molding cavity to an end wall of said core mold, the end wall of said core mold being transverse to said parting surface of said core mold, wherein said groove or recess opens to the molding cavity at said peripheral edge of the molding cavity and extends along said parting surface of said cavity molder to said end wall of said core mold, said groove or recess, said end wall, and the upper surface of the sheet material at the holding portion define, when the sheet material is located in the molding cavity and said cavity mold and said core mold are closed, a closed-end groove or recess, and said edge surface of said cavity surface of said core mold and the upper surface of the sheet material define, when the sheet material is located in the molding cavity and said cavity mold and said core mold are closed, a channel located within the molding cavity, at said peripheral edge of the molding cavity, the channel becoming smaller in cross-section towards said closed-end groove or recess for introducing molten resin from the molding cavity into said closed-end groove or recess; and an injection gate for injecting molten resin into the molding cavity, said gate opening into the molding cavity at a location remote from said channel and from said closed-end groove or recess so that the molten resin injected into the molding cavity flows along the upper surface of the sheet material to reach said edge of said cavity surface of said core mold and enter the closed-end groove or recess without accumulating at said peripheral edge of the molding cavity.