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US 5,254,306 AGranted
Method for making a double layer molded product using a dam in the mold cavity
AssigneeToyoda Gosei Co., Ltd.
InventorsYoshihiro Inada, Hiroshi Mukai, Yasunobu Teramoto, Hiroshisa Narukawa
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Abstract
A mold for making a double layer molded product, such as a molded product of sandwich construction or a hollow molded product having a dam within the mold cavity adjacent its gate. The dam projects in a direction transverse to that in which the inner-forming material is injected, and a gap is defined between the dam and the walls of the cavity. With this configuration, the core thickness of the molded product of sandwich construction, or the skin thickness of the hollow molded product, are made uniform.
Claims10
A method of molding a double layer molded product comprising:
- providing a mold including wall means defining a molding cavity;
- means defining a gate through which materials are injected into said molding cavity, said gate defining a longitudinal axis of injection;
- and means defining a dam within said molding cavity, said dam intersecting said axis of injection, at least one gap being defined between said dam and said wall means of said molding cavity;
- injecting a skin-forming material into said molding cavity through said gate;
- and
- injecting a core-forming material into said skin-forming material within said molding cavity through said gate, said core-forming material being intersected and diverted to flow through said at least one gap whereby pressure gradients along said axis of injection and in a direction transverse thereto are made substantially uniform whereby the core material is uniformly injected into the skin-forming material from said gate to more remote portions of said mold cavity.
3 more elements
Dependencies are inferred from the claim text.