| 摘要 |
PURPOSE:To fit a base cup and a biaxially stretched bottle bottom without leaving compressed air between them even though a vent is not provided in the bottom of the base cup, by loosely fitting the base cup onto the bottom of the biaxially stretched bottle after the base cup is molded but before the base cup is cooled, and then cooling the base cup. CONSTITUTION:A dome-shaped synthetic resin base cup 6 having a depending cylindrical leg 7 is loosely fitted on the bottom of a biaxially stretched bottle the bottom wall 2 of which is extended down into a semispherical shape, with the circumferential wall 8 of the base cup engaged with the lower section 3 of a bottle barrel 3, after the base cup 6 is molded and before it is cooled. Then the base cup is cooled so that the base cup 6 is contracted and the circumferential wall 8 is tightly fitted on the lower outer surface of the bottle barrel 3 thereby the bottle 1 and the base cup 6 are fitted. EFFECT:If the bottle is put into cold water, the water can not enter the space between the bottle bottom and the base cup. The fitting is positive and ready. |
