| 摘要 |
PURPOSE: To selectively and certainly form a hollow part only to a desired thick-walled part by compressing a mold up to a first mold clamping state while injecting a resin into the mold held to a semi-opened state and subsequently setting the mold to a slightly opened state in a moment to inject compressed gas into the mold to immediately compress the mold up to a second mold clamping state. CONSTITUTION: At first, a resin is injected into a mold 1 held to a semi-opened state from an injection nozzle 2 and, subsequently, a movable mold 1b is allowed to advance during the injection of the resin to perform mold clamping up to a first mold clamping state. By this mold clamping, the resin in the mold 1 is stretched to spread throughout the mold to be closely bonded to the entire inner surface of the mold. Next, the movable mold 1b is allowed to slightly retreat to momentarily set the mold to a slightly opened state and compressed gas is introduced into the resin under pressure from a gas nozzle 3 to immediately perform the compression of the resin by mold re-clamping. The compression of the resin is performed up to a predetermined wall thickness determined with respect to a molded product by this second mold clamping state and the introduction of excessive compressed gas under pressure is prevented by increasing the pressure of the resin in the mold 1 to enhance the mold reproducibility of a molded product. |
