Method of producing laminated bottles having peelable inner layer

A method of making a laminated bottle having an outer layer and an inner layer laminated on an inner surface of the outer layer so as to be capable of delaminating from the surface, the method comprising the steps of:

• injection molding an outer preform for the outer layer by injecting a molten first resin, and forming a through-hole in the outer preform being injection molded at a portion thereof facing an injection sate for injecting the second resin;
• then injection molding inside the outer preform an inner preform for the inner layer by injecting a molten second resin through the gate and also the though-hole to flow along an inner surface of the outer preform so that the preforms comprise a parison;
• and finally blow molding the laminated bottle by blowing the parison,
• wherein
• the second resin has a melting point lower than that of the first resin,
• the inner preform is injection molded so that a bulge of the second resin is formed, the bulge projecting outwardly through the through-hole from the outer preform,
• and a stretching rod used to stretch the parison longitudinally depresses and collapses the bulge at said blow molding.

A method of making a laminated bottle having an outer layer and an inner layer laminated on an inner surface of the outer layer so as to be capable of delaminating from the surface, the method applied to make the laminated bottle having at least one ventilation hole to allow ambient air to flow in between the outer and inner layers, and comprising the steps of:

• injection molding an outer preform for the outer layer by injecting a molten first resin;
• then injection molding inside the outer preform an inner preform for the inner layer by injecting a molten second resin so that the preforms comprise a parison;
• and finally blow molding the laminated bottle by blowing the parison,
• wherein
• the second resin has a melting point lower than that of the first resin,
• the ventilation hole is formed at the step of injection molding of the outer preform, and
• when the inner preform is subsequently injection molded, a second pin has been inserted from outside and through the outer preform in such a manner that an end portion of the second pin is held substantially in flush with the inner surface of the outer preform.