| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the orientation deflection of fluidity from being occurred at the bottom, and advance the impact resistance and buckling strength of the bottom by forming a bottle being a biaxial orientation blow molded article of thermoplastic resin not being affected substantially by residual distortion due to fluid orientation in the center of its bottom. SOLUTION: The bottle is formed by biaxial orientation blow molding of thermoplastic resin, and has a mouth and neck part 1, a shoulder part 2 connected to the mouth and neck part 1, a trunk part 3, and a bottom 4. The bottom part 4 is a self-standing structure, and includes the annular ground contact part 5 of a bottom circumference and upward expanded central doom part 6. In this bottle, the center of the bottom 4 is formed in a manner not being affected by residual distortion due to fluid orientation. Namely, a perform is made by the compression molding, in particular, one-step compression molding of polyester, polypropylene or the like, and then, subjecting the preform to biaxial orientation blow molding. By such a constitution, the impact resistance or buckling strength of the bottom, and furthermore, an anti-environmental cracking property in its bottom center are improved.</p> |
