| 摘要 |
PURPOSE:To obtain a molded item excellent in quality (good in fused state and less shrunk), by foaming and molding, under specific conditions using a heating medium, preliminarily foamed polypropylene resin particles having an internal pressure of at least 1 atmospheric pressure and filled in a pair of molds. CONSTITUTION:The preliminarily foamed polypropylene resin particles 2 having an internal pressure of at least 1atm (G) are filled in a molding chamber 5 defined by a first mold member 3 and a second mold member 4. Then a heating medium[steam under at least 1atm (G)]is fed in a space 6 formed between the first mold member 3 and a frame 16, and is passed through thin bores 8 in the first mold member 3, the preliminarily foamed particles 2, thin bores 9 in the second mold member 4, and a space 7 formed between the mold 4 and a frame 17 to be discharged through an outlet 14, and then similarly a heating medium is fed from the second mold member 4 and is discharged through the first mold member 3. The pressure difference between the two directions should be at least 0.51-1atm (G). |
