MULTILAYER-PREFORM, ITS MOLDING METHOD, AND MULTILAYER-BOTTLE

摘要

PROBLEM TO BE SOLVED: To improve the integral strength of an insert piece molded previously and a PET resin by forming an integral bond by introducing the PET resin into the recessed parts of numbers of uneven projections formed in the barrel part of an insert piece. SOLUTION: An insert piece 1 molded previously is set in a core die 2, a parison molding die 3 it closed around the core die 2, and a molten PET resin is introduced into the space between the inner surface of the parison molding die 3 and the peripheral surface of the insert piece 1 to form an outer surface layer 4. The molten PET resin is introduced into recessed parts formed by numbers of uneven parts 7a formed on the outer surface of the barrel part 6 of the insert piece 1, the insert piece 1 is integration-bonded firmly to the PET resin layer (outer surface layer 4) to mold a multilayer-preform 10. In this way, in the multilayer-preform, the integral strength (adhesive strength) of the insert piece molded previously and the PET resin can be improved.