METHOD FOR DECENTERING CENTER PARTING LINE FORMED ON FILM OF PIERCING NEEDLE PART OF MEDICAL CONTAINER

PROBLEM TO BE SOLVED: To provide a method for decentering a center parting line from the center of the piercing needle part of a medical container for the purpose of eliminating the possibility that a film forming material is shaved during insertion of a needle or the like and its fragments are entrained in the container, which occurs if the center parting line is formed in the center of the piercing needle part of the medical container and thereby the film of the piercing needle part is thickened, as needles are normally inserted into the center of the piercing needle part of the medical container. SOLUTION: Two areas defined by a center parting line formed in the radial direction of a piercing needle part 16a are heated so that the amount of elongation of one of the areas becomes greater than that of the other, so that the center parting line decentered from the center of the piercing needle part to the other area not yet heated.