| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a two-layered preform having high fusion strength at the fusion interface of the inner surface of an outer layer shell and the outer surface of an inner layer shell, generating no interfacial shift at the time of biaxially stretching blow molding, and imparting a two- layered bottle strongly resisting external load. SOLUTION: In the method for manufacturing the two-layered preform by inserting before hand the outer layer shell in the cavity of the female mold of an injection mold for the preform so as to be closely brought into contact with the surface of the cavity and integrating the inner layer shell with the inside of the outer layer shell by injection molding, the surface temperature of the outer layer shell 100 is raised by preheating to insert the outer layer shell in the injection mold for the preform and the inner layer shell 200 is integratedly injection molded in the inside of the outer layer shell of which the surface temperature is high by injection molding. |
