| 摘要 |
PROBLEM TO BE SOLVED: To obtain a molded form, having an ever surface state from delustered state-high luster state and prominent in the appearance thereof without any wrinkle, rib or projection and recess on the surface thereof, by a method wherein a mold is closed by interposing a plastic film, not molten at the specified temperature of the mold, between the mold of the specified temperature and a hot parison, constituting of polypropylene. SOLUTION: Blow molding is effected by a method wherein a hot parison is formed through the extrusion molding of polypropylene and a mold is closed while blowing gas into the parison or after effecting preblow molding. In this case, the mold is closed whole interposing a plastic film, not molten by the temperature of the mold or the parison, between a mold, having a temperature higher than 90 deg.C and lower than 160 deg.C, and the hot parison. Homo-polypropylene, containing a coloring agent, is preferable as the polypropylene. A polyethylene terephthalate polycarbonate film and polyamide film are preferable as the plastic film. |
