Patent ID: 8652390

Claim:
A method for manufacturing a synthetic resin container in which a molten resin in a predetermined amount is supplied to a pair of molds including an upper mold and a lower mold provided with a cavity corresponding to a desired container shape, followed by compression molding by a compression molding apparatus comprising a lower mold driving unit which applies a compression load to the lower mold while moving the lower mold upward during clamping, and an upper mold driving unit which is switchable between a low-pressure driving lowering the upper mold to a predetermined stroke length and a high-pressure driving applying to the upper mold a load higher than the compression load which is applied to the lower mold, wherein after the upper mold is moved downward for the predetermined stroke length such that the upper mold approaches the lower mold in which the molten resin has been supplied, the compression load is applied to the lower mold while moving the lower mold upward by driving the lower mold driving unit simultaneously with or after switching the upper mold driving unit from the low-pressure driving to the high-pressure driving.