| 摘要 |
<p>PURPOSE:To prevent breakage or the like of a bottom from occurring by providing a peripheral rib contiguous in a peripheral direction on a bottom summit region which is shaped like a downward protrusion and setting a radius from a center of the bottom to the peripheral rib in a specific relation. CONSTITUTION:A blow mold 10 for detecting a self-standing bottle forms respectively opposing cavity faces 10A, 10B at bottle body and a bottom with a plurality of radii S1, S2. A ring-like protrusion 10D forming a peripheral rib is provided on the cavity face 10B. A position where the ring-like protrusion 10D is formed is set as R2<R<=R1, wherein a radius from the center of the bottom to inside of the ring-like protrusion 10D is R between an inversion point P and a gate trace, a radius from the center of the bottom to a shape inverting point P at a border for transferring toward a leg forming cavity face 10C is R1, and a radius of the gate trace remaining on the bottom is R2. Thus withstanding internal pressure property can be secured.</p> |
