Abstract: A testing apparatus for testing the level of retained gas at elevated pressure in plastic containers for carbonated beverages includes a manifold assembly for engaging the mouth of a test set of the containers. The apparatus additionally includes a gas supply for supplying a desired quantity of a selected gas to each container, the gas preferably helium. The apparatus further includes pressure measuring units for measuring the pressure in each container, and a data collection system coupled to the pressure measuring units for periodically collecting pressure data along with ambient temperature data as a function of time. The collected data can be analyzed to determine shelf life of the containers. Using helium, the shelf life determination can be accomplished in about 1/7th the time of conventional shelf life tests.

Abstract: A testing apparatus for testing the level of retained gas at elevated pressure in plastic containers for carbonated beverages includes a manifold assembly for engaging the mouth of a test set of the containers. The apparatus additionally includes a gas supply for supplying a desired quantity of a selected gas to each container, the gas preferably helium. The apparatus further includes pressure measuring units for measuring the pressure in each container, and a data collection system coupled to the pressure measuring units for periodically collecting pressure data along with ambient temperature data as a function of time. The collected data can be analyzed to determine shelf life of the containers. Using helium, the shelf life determination can be accomplished in about {fraction (1/7)}th the time of conventional shelf life tests.

Abstract: A plastic container comprises a lower base forming portion that includes a plurality of circumferentially spaced downwardly convex segments (126) and a plurality of intervening, circumferentially spaced, totally convex, hollow foot forming portions (121) that extend radially from the central bottom portion (120) and downwardly from the downwardly convex segments to form a clearance (124) for the central bottom portion. The downwardly convex segments have smoothly curved cross sections, in radially extending planes through their central regions and coplanar with the container's longitudinal axis (120a).

Abstract: An improvement for a stretch blow molding apparatus, including a cryogenic liquid pulse pump disposed in sealed fluid connection between a cryogenic liquid reservoir and a stretch blow molding machine, a subcooler connected between the reservoir and the pulse pump for supplying cryogenic liquid at a preselected temperature, a vacuum jacket casing disposed generally surrounding a stretch blow rod, the reservoir, and the pulse pump for preventing vaporization of cryogenic liquid prior to delivery into a container, and control means for controlling the pulse pump to deliver a preselected amount of cryogenic liquid into the container through the stretch rod during a predetermined time interval beginning at a preselected time after formation of the container.