PRESSURE COMPENSATING BASES FOR POLYMERIC CONTAINERS

摘要

The present invention provides a plastic container having a sidewall (29) defining a chamber and having a first end and a second end and an opening at the first end into the chamber. A base (10) extends from the sidewall and closes the second end. The base has an outer perimeter portion defining a support structure (114) and an axially inwardly extending perimeter (122) wall spaced radially inwardly from the support structure forming an angle with a horizontal line of greater than about 80°. A centrally disposed push-up section (116) in the shape of an axially inwardly extending truncated cone (128) and a toroidal-shaped channel (129) circumscribing and connects the perimeter wall to the push-up. The toroidal-shaped channel has a surface that is asymmetrical about a central axis of the container when the container is under static pressure conditions.