BLOW-MOLDED BOTTLE-SHAPED CONTAINER OF BIAXIALLY ORIENTED POLYETHYLENE TEREPHTHALATE AND PIECE TO BE BLOW-MOLDED INTO THE SAME BOTTLE-SHAPED CONTAINER

摘要

A hollow blow-molded bottle-shaped container of a biaxially oriented polyethylene terephthalate which includes an integrally formed body, shoulder and neck portion and wherein there is a stepped portion on the inner peripheral surface of the boundary between the neck portion and the shoulder portion. The neck portion is crystallized by a heat treatment before being biaxially oriented blow-molded from an injection-molded primary piece or parison. The thickness of the wall at the boundary between the neck portion and the shoulder portion reduces abruptly to substantially equal to the thickness of the body portion. This bottle-shaped container is manufactured from a preformed piece or parison injection-molded. The parison has a recess groove formed on the peripheral surface of the shoulder forming portion at the boundary with the neck portion.