초록 ▼

A control system for a gas assisted injection molding apparatus which provides precise and reproducible indication of when the injection of plastic is to terminate and when the pressured gas is to be introduced on basis of sensing of the location of the flow front of the injected plastic in the mold

A control system for a gas assisted injection molding apparatus which provides precise and reproducible indication of when the injection of plastic is to terminate and when the pressured gas is to be introduced on basis of sensing of the location of the flow front of the injected plastic in the mold cavity. The flow front sensor control system according to the present invention includes: one or more sensors located at one or more predetermined locations of the cavity of a mold of a gas assisted injection molding apparatus, a controller which processes sensed data from the one or more sensors and thereupon sends a signal to the gas assisted plastic injection molding apparatus to discontinue plastic injection and introduce pressured gas. The preferred type of sensor is a temperature sensor; however, other types of sensors, such as a pressure sensor, may be used.

대표청구항 ▼

A method for providing selective control of a gas assisted plastic injection molding apparatus comprising the steps of: introducing plastic by injection into a mold; sensing data with respect to location of a flow front of injected plastic within a cavity of a mold of a gas assisted plastic injectio

A method for providing selective control of a gas assisted plastic injection molding apparatus comprising the steps of: introducing plastic by injection into a mold; sensing data with respect to location of a flow front of injected plastic within a cavity of a mold of a gas assisted plastic injection molding apparatus; comparing the sensed data with stored data; generating a “stop injection”signal and sending said “stop injection”signal to the gas assisted plastic injection molding apparatus to thereby cause the gas assisted plastic injection molding apparatus to cease introduction of plastic into the mold in response to detecting at said step of comparing a predetermined change in data between said sensed data and said stored data; and generating a “start gas”signal and sending said “start gas”signal to the gas assisted plastic injection molding apparatus to thereby cause the gas assisted plastic injection molding apparatus to begin introduction of pressurized gas into the mold in response to said step of detecting a predetermined change in data between said sensed data and said stored data.