Abstract: A preform having an inverted truncated conical bottom section is used. The inclined inner surface of a bottle bottom surface-forming portion of the bottom section is formed into a gently curved convex surface that extends from the lower portion of a bottle bottom edge-forming portion of the bottom section to a curved portion in the lower portion of the bottom section so that the thickness of the bottle bottom surface-forming portion is greater than the thickness of the barrel section of the preform and the thickness of the bottle bottom edge-forming portion. The increase in thickness of the bottom section improves the efficiency of stretching the bottom section, and the circumferential wall of the bottom section can thereby be efficiently stretched. This allows a reduction in weight (thickness) of the bottom surface section of a stretch blow molded bottle, and a reduction in weight of the bottle is thereby achieved.

Abstract: A preform of injection-molded PET has a body wall thickness of 3.0-4.5 mm. The preform is high-temperature mold-released from an injection cavity mold and an injection core. Pre-blowing of the preform is restricted at 5±0.5 seconds after the mold release, at a temperature of 112-117° C. of the pre-blow mold, and for a pre-blowing time of 0.5-1.0 second. Air blowing is applied to expand only the body of the preform. Stretch blow molding is performed restrictively at 3-4 seconds after the mold release from the pre-blow mold, at a temperature of 103-107° C. of the blow mold, and for an air blowing time of 6-9 seconds, thereby stretch blow molding the preform into a bottle and simultaneously heat setting to impart heat resistance to the bottle.

Abstract: A preform having an inverted truncated conical bottom section is used. The inclined inner surface of a bottle bottom surface-forming portion of the bottom section is formed into a gently curved convex surface that extends from the lower portion of a bottle bottom edge-forming portion of the bottom section to a curved portion in the lower portion of the bottom section so that the thickness of the bottle bottom surface-forming portion is greater than the thickness of the barrel section of the preform and the thickness of the bottle bottom edge-forming portion. The increase in thickness of the bottom section improves the efficiency of stretching the bottom section, and the circumferential wall of the bottom section can thereby be efficiently stretched. This allows a reduction in weight (thickness) of the bottom surface section of a stretch blow molded bottle, and a reduction in weight of the bottle is thereby achieved.

Abstract: A preform of injection-molded PET has a body wall thickness of 3.0-4.5 mm. The preform is high-temperature mold-released from an injection cavity mold and an injection core. Pre-blowing of the preform is restricted at 5±0.5 seconds after the mold release, at a temperature of 112-117° C. of the pre-blow mold, and for a pre-blowing time of 0.5-1.0 second. Air blowing is applied to expand only the body of the preform. Stretch blow molding is performed restrictively at 3-4 seconds after the mold release from the pre-blow mold, at a temperature of 103-107° C. of the blow mold, and for an air blowing time of 6-9 seconds, thereby stretch blow molding the preform into a bottle and simultaneously heat setting to impart heat resistance to the bottle.

Abstract: A biaxial stretching bottle in which a pair of carrying handles are provided oppositely constituted on both sides of a neck portion in such a manner as to be bent freely, and the biaxial stretching bottle having the carrying handle with a structure which can improve durability strength of a base portion and a connection structurally. A pair of U-shaped carrying handles, which a handle grip portion and an arm portion of both sides are formed integrally, are connected to and formed on both ends of the base portion constituted by overhang pieces formed on the symmetrical positions of both sides of the neck portion. Brackets are constituted unitarily across the lower surface of the vicinity of both ends of the base portion and a side surface of the neck portion and stoppers are projected and arranged on the upper surface of the base portion.

Abstract: In a vent arrangement comprising a heating cylinder 1 containing therein a screw and provided with a vent hole 3 and a reduced pressure exhaust path 4 provided with a vacuum pump and connected to the vent hole 3 for draining volatile fractions of a material to be molded from the heating cylinder by reducing the pressure in the vent hole by means of the vacuum pump, said volatile fractions are removed by arranging in the exhaust path a filter unit 7 filled with a granular filtering material 8. The material to be molded is used for the filtering material 8. According to the above construction, it can be achieved to efficiently remove volatile matters by using the molded material as the filtering material of the filter unit arranged in the reduced pressure exhaust path of a vent arrangement.