| 摘要 |
A process and apparatus for annealing biaxially oriented articles is disclosed, particularly blow molded articles prepared from unique tapered preforms which are immediately annealed using warm fluid in a segmented mold. Portions of the segment mold, used to form the articles, are temperature controlled at various temperatures by passing warm water through conduits in the neck-shoulder portion and body portion of the mold segment and cold water through the bottom and shoulder portion of the mold to bring the temperature of the article wall to about 65 DEG C. to 85 DEG C. for PET bottles. The body wall temperature is preferably lowered to about 80 DEG C. while the neck-shoulder and bottom and shoulder portions are lowered to at least 70 DEG C. The annealing increases the articles structural strength, removes temperature and biaxial stress, reduces gas permeability, retains transparency and allows for multiple reuse of the article including hot washing thereof. |
