Refillable pet container

1. A refillable container comprising:

a finish defining an opening to an internal volume of the container, the finish at a first end of the container;

a base at a second end of the container that is opposite to the first end;

a standing surface included with the base at the second end; and

a push-up portion of the base surrounded by the standing surface, the push-up portion including:

a central portion at a center of the base and recessed inward from a plane extending across the standing surface, a longitudinal axis of the container extends from the first end to the second end through the central portion; and

a substantially linear portion extending radially outward from the central portion to a standing ring of the base;

wherein the substantially linear portion and the central portion are movable away from the first end of the container in response to an increase of internal pressure within the container and towards the first end of the container when the pressure decreases, the substantially linear portion remains substantially linear as the substantially linear portion moves towards the first end of the container;

wherein the substantially linear portion gradually and uniformly decreases in thickness as the substantially linear portion extends outward from the central portion to the standing ring; and

wherein the substantially linear portion is at a first acute angle relative to a plane extending across the standing surface and moves to a second acute angle relative to the plane after the substantially linear portion moves away from the first end of the container in response to the increase of internal pressure within the container.

2. The refillable container of claim 1 , wherein the standing surface is a ring surrounding the push-up portion.

3. The refillable container of claim 1 , wherein the substantially linear portion extends radially outward from the central portion at an angle of about 20° relative to the plane extending across the standing surface.

4. The refillable container of claim 1 , wherein the substantially linear portion is thickest at the central portion.

5. The refillable container of claim 1 , wherein proximate to the central portion the substantially linear portion is about twice as thick as proximate to the standing surface.

6. The refillable container of claim 1 , further comprising a stepped portion of the base extending between the standing surface and the substantially linear portion.

7. The refillable container of claim 6 , wherein the stepped portion extends about 1 mm from the standing surface to the substantially linear portion.

8. The refillable container of claim 1 , wherein the push-up portion has a maximum push-up diameter that is 5.7 times greater than a maximum center diameter of the central portion.

9. The refillable container of claim 8 , wherein:

the push-up portion has a maximum push-up diameter of about 65 mm; and

the central portion has a maximum central diameter of about 11.41 mm.

10. The refillable container of claim 1 , wherein the container has a maximum total diameter that is 1.6 times greater than a maximum push-up diameter of the push-up portion.

11. The refillable container of claim 1 , further comprising a heel extending from the standing surface to a sidewall of the container;

wherein the container has a total container radius of curvature that is about 1.5 times greater than a heel radius of curvature of the heel.

12. The refillable container of claim 11 , wherein:

the heel radius of curvature is about 34.5 mm; and

the total container radius of curvature is about 51.75 mm.

13. The refillable container of claim 1 , wherein the central portion is recessed about 10 mm inward from the plane extending across the standing surface.

14. The refillable container of claim 1 , further comprising a bumper between the base and a body of the container.

15. The refillable container of claim 14 , wherein the push-up portion of the base has a push-up portion total surface area that is four times less than a total surface area of the base below the bumper.

16. The refillable container of claim 15 , wherein the push-up portion total surface area is about 35.6 cm 2 , and the total surface area of the base below the bumper is about 147.2 cm 2 .

17. The refillable container of claim 1 , wherein the push-up portion is generally cone-shaped.

18. The refillable container of claim 1 , further comprising a gate at a center of the central portion.

19. The refillable container of claim 1 , wherein the container is configured to be filled, emptied, and refilled at least 15 times without stress cracking failure occurring at the base.

20. The refillable container of claim 1 , wherein the container is configured to be filled, emptied, and refilled at least 25 times without stress cracking failure occurring at the base.

21. The refillable container of claim 1 , wherein the container is configured to be filled, emptied, and refilled at least 32 times without stress cracking occurring at the base.

22. The refillable container of claim 1 , wherein the container is configured to withstand an accelerated test run at least 25 times without stress cracking failure at the base, the accelerated test including the following:

washing the container with a caustic solution;

rinsing the container with water;

filling and capping the container with a product; and

heating the filled container to an elevated temperature for a predetermined period of time.

23. The refillable container of claim 22 , wherein the product is carbonated.

24. The refillable container of claim 1 , wherein the container is configured to withstand an accelerated test run at least 25 times without stress cracking at the base, the accelerated test including the following:

washing the container with a caustic solution;

rinsing the container with water; and

pressurizing the container for a predetermined period of time.

25. The refillable container of claim 1 , wherein a ratio of a total surface area of the push-up portion to a projected surface area of the push-up portion is less than 1.2.

26. The refillable container of claim 1 , wherein a ratio of a total surface area of the push-up portion to a projected surface area of the push-up portion is about 1.07.