초록 ▼

A method of injection molding for use with an injection molding machine includes: a) generating pressurized gas and pressurized moisture within molten plastic as plastic pellets are plasticized in the injection molding machine, the pressurized gas and the pressurized moisture having a total pressure

A method of injection molding for use with an injection molding machine includes: a) generating pressurized gas and pressurized moisture within molten plastic as plastic pellets are plasticized in the injection molding machine, the pressurized gas and the pressurized moisture having a total pressure defining an internal counterpressure within the molten plastic; (b) pressuring air within a cavity of a mold in the injection molding machine to an air pressure level which is substantially equal to the internal counterpressure in order to counterbalance the internal counterpressure as the molten plastic is injected into the cavity, thus providing a substantially pressure balanced molding environment for the plastic; and (c) maintaining the air pressure level in the cavity substantially constant as the molten plastic is injected into the cavity. A mold apparatus for use with the method of injection molding includes selectively sealed venting of the mold cavity, the vents being configured to maintain a substantially constant air pressure within the cavity as the cavity is filled with molten plastic.

대표청구항 ▼

[ What is claimed is:] [1.] A method of injecting molten plastic into a mold cavity, comprising:pressurizing a gas in the mold cavity prior to injection of molten plastic into the mold cavity and generating static pressure in the molten plastic;commencing injection of the molten plastic into the mol

[ What is claimed is:] [1.] A method of injecting molten plastic into a mold cavity, comprising:pressurizing a gas in the mold cavity prior to injection of molten plastic into the mold cavity and generating static pressure in the molten plastic;commencing injection of the molten plastic into the mold cavity; andsensing, mathematically deriving and monitoring the static pressure of the molten plastic and the pressure of the gas in the mold cavity as the molten plastic is injected into the mold cavity.