| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technique for the creation of a bottom shape in order to suppress the generation of sink marks in a ground contact portion of a bottom portion of a square bottle body by biaxial stretch-blow-molding. <P>SOLUTION: In this square bottle body made of a synthetic resin which is biaxially stretch-blow-molded, the annular ground contact portion is arranged on the peripheral edge part on the bottom surface of the bottom portion, and a concave recess portion is arranged at the central part. In the concave recess portion, a plurality of radial ribs are extended into a radiation form by expanding the concave wall outward. The extending range of the radial ribs is made into a range from the peripheral edge of the top part of the concave recess portion to a vicinity of the inner peripheral edge of the ground contact portion. In the concave recess portion, the plurality of radial ribs in the range from the peripheral edge of the top part of the concave recess portion to the vicinity of the inner peripheral edge of the ground contact portion are extended into the radiation form by making the concavewall of the concave recess portion expand in the outside direction. The extending length of the radial ribs which are extended in a direction closer to the horizontal central direction of the sidewall from among adjacent radial ribs is constituted to be shorter than the extending length of the radial ribs which are extended in a direction closer to the corner wall direction. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
