| 摘要 |
PURPOSE:To shorten the molding cycle by making effective use of sensible heat brought-in by gas heating and cooling the inside of a parison, by a method wherein a gas introducing pipe introducing gas heating or cooling the inside of the parison and a gas discharging pipe discharging the gas at the time of molding are fitted to a mold by separating them from each other. CONSTITUTION:A surface part region 20 of a mold is heated beforehand by a heating medium and the same is heated and supported by a radiant tap controlled heater 60. At a point of time when a parison 2 is extruded and both molds 3, 4 are mold- registered, a gas discharge pipe 103b and gas introducing pipe 103a are moved forward into an insertion through hole provided into the female mold 4, the front end parts of which are entered within the parison 2 and gas is discharged continuously through the gas discharge pipe 103b while introducing heating medium through the gas introducing pipe 103a. Furthermore, high-speed heating and high-speed cooling become possible by a method wherein cooling of the surface part region of the mold is performed by changing over from the heating medium to a cooling medium and also the parison is molded and solidified by changing over from heating blowing air to cooling blowing gas. The gas introducing pipe 103a and gas discharging pipe 103b are separated from each other as much as possible and a pressure control valve is provided on an outlet side of the discharging pipe 103b. |
