Method for producing delamination container and apparatus for producing delamination container

A manufacturing method for manufacturing a delamination container, the manufacturing method comprising:

• an injection molding process of injection-molding a preform having a two-layer structure including an outer layer and an inner layer;
• and
• a blow molding process of blow molding the preform to mold the delamination container made of a resin,
• wherein the injection molding process includes:
• an outer layer molding process of molding the outer layer by filling a first injection mold with an outer layer resin material and molding a thin film portion on a thin-film forming part which is a part of the outer layer,
• a thin film portion breaking process of breaking the thin film portion formed in the outer layer molding process, and
• an inner layer molding process of injecting an inner layer resin material from an outside of the thin-film forming part of the outer layer in which the thin film portion is broken in the thin film breaking process, and filling a second injection mold with the inner layer resin material having a temperature lower than a melting point of the outer layer resin material to mold the inner layer,
• wherein the first injection mold includes a first injection cavity mold and a first injection core mold,
• wherein the thin film portion is formed on a bottom portion of the outer layer of the preform, and
• wherein in the outer layer molding process,
• the thin film portion is formed by, after the first injection cavity mold is filled with the outer layer resin material, moving a valve pin of a hot runner mold that supplies the outer layer resin material to the first injection cavity mold toward the first injection core mold and cooling the outer layer resin material for a predetermined time in a state where an outer surface of the thin-film forming part of the outer layer is recessed by a tip portion of the valve pin.