| 摘要 |
PURPOSE:To carry out the expansion of a parison uniformly by a method wherein ultrasonic vibration is imparted to a core under a condition adhered to the bottomed parison to separate the parison from th core and, after separation, the parison is subjected to blow molding. CONSTITUTION:Through an injection nozzle 8, a gap 5 formed between a cavity 1 and a core 3 is filled with a resin to mold the same into a parison 10 and, after molding, power is applied to an ultrasonic oscillator 7 to generate ultrasonic vibration with predetermined frequency in the core 3 and the core 3 is vibrated to separate the parison 10 and the core and, after a gap 11 is fomed between the parison 10 and the core 3, a non-sticky liquid is poured into the gap 11 from a blow-in slit 6 to form an adhesion preventing layer between the core 3 and the parison 10. Subsequently, the core 3 is separated from the cavity 1 and mounted in a blow mold 9 to carry out the blow molding. By this method, a molded product free from injured parts, wrinkle and thickness variation can be prepared simply and certainly. |
