Bottom shape of flat bottle made of synthetic resin

摘要

PROBLEM TO BE SOLVED: To provide a bottom shape of a synthetic resin made flat bottle which suppresses the generation of a bottom fall in a heat resistant flat bottle, and is excellent in grounding stability.SOLUTION: In a bottom shape of a synthetic resin made flat bottle, the synthetic resin made flat bottle is composed of a mouth cylindrical part, a shoulder, a trunk and a bottom, and formed by biaxial stretch blow molding. The bottom has the bottom shape having a grounding part located at a peripheral edge, and a tapered peripheral wall which is continued to the inside of a bottle radial direction from the grounding part and upwardly extends, and a center bottom face wall which extends from the tapered peripheral wall. The tapered peripheral wall in a long diameter part of the flat bottle extends so as to be inclined to the inside of the bottle radial direction from the grounding part toward the center bottom face wall, an inclination angle of the tapered peripheral wall with respect to a line which is orthogonal to a bottle axis is larger than 30 degrees and smaller than 90 degrees, and two or more ribs on a diagonal face with the bottle axis as center are radially extended at the tapered peripheral wall in a short diameter part of the flat bottle.