초록 ▼

A process for producing an injection molded product includes introducing a stream of plastic material into a mold space at a first pressure. A quantity of gas is stored in a storage chamber at a second pressure which is at least as high as the first pressure. The gas is introduced into the molten st

A process for producing an injection molded product includes introducing a stream of plastic material into a mold space at a first pressure. A quantity of gas is stored in a storage chamber at a second pressure which is at least as high as the first pressure. The gas is introduced into the molten stream of plastic material immediately after the molten material has passed the position at which the gas is introduced thereby forming a gas cavity in the molten material. The gas exerts pressure on the surrounding plastic material to urge the material toward the surfaces of the mold space. As the feeding of the plastic material into the mold space continues, the injection of the gas is also continued. The supply of molten material is terminated when the surfaces of the mold space are completely covered by the molten material. A pressure is held within the gas cavity as the plastic material cools. Subsequently, the pressure is released to bring the gas cavity to ambient pressure. Then the mold is opened to remove the hollow shaped article. An apparatus for producing an injection molded product is also disclosed.

대표청구항 ▼

A process for producing an injection molded project, comprising: supplying a plastic material; introducing a molten stream of the plastic material into a mold space at a first pressure; introducing a gas into said molten stream of plastic material immediately after said molten material has passed a

A process for producing an injection molded project, comprising: supplying a plastic material; introducing a molten stream of the plastic material into a mold space at a first pressure; introducing a gas into said molten stream of plastic material immediately after said molten material has passed a position at which the gas is introduced thereby forming a gas cavity in the molten material, the gas being introduced at a second pressure, the gas in said gas cavity exerting pressure on the surrounding plastic material to urge the material toward a surface of said mold space; continuing to feed plastic material to said mold space; simultaneously continuing to inject gas into said gas cavity; terminating the supply of molten material; terminating the supply of gas; subsequently maintaining a pressure within the gas cavity as the plastic material cools and solidifies; and, venting the gas from said gas cavity at a controlled rate.