| 摘要 |
PURPOSE:To manufacture a bottle having excellent heat resistance and strength, by a method wherein a thick part of the bottom of a primary bottle made of polyethylene terephrthalate resin is preheated to a predetermined temperature, and the crystallinity is increased further by heat-treating the whole of the same. CONSTITUTION:A preform 1 made of polyethylene terephthalate resin is heated at a stretching temperature, and a primary bottle 2 which is of a larger form than that of a final product is formed by performing primary blow molding. An unoriented or low-oriented thick part of the bottom 2a of the primary bottle is preheated to a temperature of 150 deg.C or higher in succession. While increasing the crystallinity by heat-treating the whole of the bottle within an atmosphere of the temperature of 150 deg.C or higher, a secondary bottle 5 which is of a form smaller than that of the final product is formed through free contraction. Then the same is formed into the title bottle 6 having a form of the final product by performing a second blow molding within a mold having a form of the final product. |
