Method of inverting container base prior to cooling

A method for hot-filling a polymeric container made of a container material with heated product comprising:

• hot-filling the polymeric container with the heated product;
• heating the container material above a glass transition temperature, during the hot-filling the heated product heats the container above the glass transition temperature;
• capping the polymeric container after the container has been hot-filled by screwing a cap onto a threaded finish of the container;
• mechanically inverting with a mechanically adjusted pusher a center inversion area of a base of the polymeric container from a convex configuration to a concave configuration prior to the container cooling below the glass transition temperature to create a positive pressure within the container that reinforces the container, the center push-up portion is adjacent to, and surrounded by, a fixed portion of the base that remains stationary during mechanical inversion of the center push-up portion, the fixed portion includes a heel and a standing surface extending inward from the heel to the center push-up portion, the center inversion area of the base is inward of the standing surface in both the convex configuration and the concave configuration;
• and
• subsequent to mechanically inverting the base, cooling the container below the glass transition temperature in a cooling tunnel to create a negative pressure vacuum within the container;
• wherein the positive pressure reinforces the container during conveying and cooling of the container to decrease occurrences of denting as the container cools below the glass transition temperature.