PURPOSE: To prevent accumulation of an olegomer component on the internal wall surface of a die and continuously manufacture the captioned bottle by applying a parting agent on the external wall surface of an intermediate material of a bottomed cylindrical shape beforehand and elongating, expanding and thermosetting the said intermediate material in a biaxial direction.
CONSTITUTION: A parting agent is applied on the external wall surface of an intermediate material of a bottomed cylindrical shape beforehand and then is blow- formed, when a transparent polyester bottle is manufactured using the said intermediate material. Edible oil, machine oil, silicon oil, liquid paraffin, vaseline, etc. are recommended as a parting agent. It is applied on the external wall surface of an intermediate material by methods such as immersion, spray, roller coating, etc. As a result, it is possible to prevent troubles such as the difficulty to remove a formed product because of its sticking to the internal wall surface of a die attributed to the accumulation of the oligomer component of saturated polyester resin components constituting an intermediate material on the internal wall surface of a die when a blow-forming is carried out or a dulling generated on the surface of a formed product.
ITAKURA TAKESHI