| 摘要 |
<p>PURPOSE:To obtain a pressure-resistant plastic bottle which is excellent in resistance to stress-cracking and resistance to rocking by making a bottom of a draw-blown molded bottom in a predetermined shape and size. CONSTITUTION:A bottom shape of a pressure-resistant plastic bottle having resistance to stress-cracking and rocking comprises a bottom center part 8 of an approximately flat small- diameter circumference, approximately spherical valley parts 9 and peak parts 10 which protrude outward along axial directions from the valley parts and in contact with a supporting face are provided alternately on an outer periphery of the center part 8, wherein the valley parts 9 and the peak parts 10 are smoothly connected on a side of the center with respect to the center part 8, while the valley parts 9 are located on a face of a rotating body and the peak parts 10 comprise inner peripheral parts 12 inside a top 11 and outer peripheral parts 13 outside the top 11. The peak parts 10 and the valley parts 9 are located alternately, and the number of them is 3 to 8, preferably an odd number. Projection areas of the peak parts and the valley parts are 40 to 65% and 6 to 30% respectively of the entire circular area, while a distance R1 from the center of the spherical part and an outer side of the top is 1.2 to 1.5 times a radius of curvature R0 of the spherical part and a ratio D1/D0 of a top diameter D1 against a body diameter D0 is 0.65 to 0.85. A diameter D2 of a circumference of the bottom center is 5 to 25mm, while D2/D1 is preferably 0.1 to 0.3.</p> |
