| 摘要 |
PURPOSE:To manufacture a bottle which necessitates no reinforcing rib by a structure wherein the bulge part is formed in an arcuate surface along the direction of its center line so as to swell outwards. CONSTITUTION:The inner surface at the central portion of a mold 1 for blow molding is formed in an arcuate surface 3 along the direction of its center line. In addition, slits 6 are formed on the inner periphery of the mold 1 at positions shaping the upper and lower parts of the arcuate surface 4. When a saturated polyester preform is biaxially stretched, the air outside the preform is discharged from the interior of the cavity of the mold through the slits 6 to the outside of the mold. After that, the expanded preform comes into close contact with the inner surface of the mold 1 and the heat setting treatment of the preform is also performed perfectly. A formed bottle has a shape faithful to the shape of the inner surface of the mold 1. |
