| 摘要 |
PURPOSE:To prevent the polyester hollow container from occurrence of draw down at a bottom when the molded product is unloaded from a blow-mold, by a method wherein a pre-molded product with a bottom made of polyethylene terephthalate resin is blow-molded in the blow-mold at a given temperature after or at the same time when it is stretched. CONSTITUTION:After or at the same time when the pre-molded product with a bottom made of polyethylene terephthalate resin is stretched in an axial direction at 80-150 deg.C, the pre-molded product is blow-molded in a transverse direction, enabling a side temperature and bottom temperature of a blow-mold to remain within a range of the inequality I (where T1 is the side temperature, T2 is the bottom temperature, and Tg a glass transition temperature of polyester) to produce a biaxially-orientated hollow container. The hollow container is molded such that a shoulder part and a drum part are required to be biaxially-stretched, oriented 3-25 folds in the percent of areal stretch as against the corresponding part of the pre-molded product, and 6-16 fold is suitable. |
