| 摘要 |
A preform for making a PET container (20) such as a bottle for a carbonated soft drink includes an outer wall (12) that defines an interior space into which a pressurized fluid may be introduced to expand the preform into a container which includes an interior layer of a first PET material (16) having a first average molecular weight, and an exterior layer (18) of a second PET material having a second average molecular weight that is different from the first average molecular weight. This makes possible a container that has improved stress crack resistance and material creep resistance, in comparison to conventional PET containers, at given wall thickness. |
