Container base structure responsive to vacuum related forces

A plastic container having a base portion adapted for vacuum absorption, said container comprising:

• an upper portion having a mouth, a body extending from said upper portion to a base, said base closing off a bottom of said container, said upper portion, said body and said base cooperating to define a chamber into which product can be filled;
• said base including a contact ring upon which said container is supported, said base further including an upstanding wall and a recessed portion, said upstanding wall being adjacent to and generally circumscribing said contact ring, said recessed portion being defined in at least part by a substantially flat base region and a central base region, said central base region being inwardly domed and located centrally within said flat base region, said flat base region extending from said upstanding wall toward a longitudinal axis of said container, said flat base region generally circumscribing said central base region and being generally planar when viewed in a one-half cross-section taken axially through said base, said flat base region defining a projected surface area of at least 45% of a total projected surface area of said container, said flat base region being moveable to accommodate vacuum forces within said container.

A plastic container having a base portion adapted for vacuum absorption, said container comprising:

• an upper portion having a mouth defining an opening into said container, a body portion extending from said upper portion to a base, said base closing off an end of said container;
• said upper portion, said body portion and said base cooperating to define a receptacle chamber within said container into which product can be filled;
• said base including a chime extending from said sidewall portion to a contact ring which defines a surface upon which said container is supported, said base further including a recessed portion defined in at least part by a flat base region extending toward a longitudinal axis of said container, said flat base region being movable to accommodate vacuum forces generated within said container, said flat base region at least partially circumscribing said axis, said flat base region defining at least 45% of a total projected surface area of said base, and a central base region being located centrally within said flat base region and defining a substantial surface deviation from said flat base region.