Production method for a delaminatable laminated bottle

A production method for a delaminatable laminated bottle which includes an outer layer and an inner layer provided on an inner surface of the outer layer and delaminatable from the outer layer, the outer layer having an introduction hole for introducing air into a space between the outer layer and the inner layer, the method comprising the steps of:

• injection-molding an outer layer preform;
• injection-molding an inner layer preform inside the outer layer preform;
• blow-molding the delaminatable laminated bottle from a laminate parison including the outer layer preform and the inner layer preform;
• and
• performing a defect checking operation,
• wherein the introduction hole is formed in the outer layer preform, and a test hole is formed in a mouth portion of the outer layer preform, to communicate with the space between the outer layer and the inner layer, in the outer layer preform injection molding step,
• wherein the inner layer preform is injection-molded with pins being inserted in the introduction hole and the test hole from an outer periphery of the outer layer preform and with distal ends of the pins being flush with an inner surface of the outer layer preform in the inner layer preform injection molding step,
• wherein the parison is blow-molded with the introduction hole being located in a predetermined circumferential position with respect to a blow-molding mold in the blow molding step,
• wherein air communication between the test hole and the introduction hole of the delaminatable laminated bottle produced by the blow molding is checked for detecting defectiveness of the introduction hole in the defect checking step.