Patent ID: 7497976

Claim:
A method of obtaining a molded product by injecting a molten resin into a cavity formed between a set of dies when said set of dies are closed, the method comprising: disposing a vacuum tank within the set of dies; keeping a pressure in the vacuum tank that is lower than ambient atmospheric pressure; forming an exhaustion channel for directly connecting a circumferential portion of said cavity with said vacuum tank by closing said set of dies; exhausting said cavity by aspirating air within said cavity when opening said exhaustion channel to said vacuum tank, wherein the vacuum tank has a volume capacity at least as large as a total of the volume capacity of the cavity and a volume capacity of the exhaustion channel; forming a gas vent portion on a periphery of the cavity, the gas vent portion providing gas communication between the cavity and the exhaustion channel; setting a gap size of the gas vent portion to permit a gas to flow between the cavity and the exhaustion chamber and disallowing substantially more viscous fluids from flowing between the cavity and the exhaustion chamber.