Flexible containers with bottom support structure

1. A disposable stand-up flexible container comprising:

a product volume made from a flexible material;

a plurality of structural support members, which supports the product volume, wherein each of the structural support members includes an expanded structural support volume made from a flexible material and expanded by an expansion material above atmospheric pressure, and wherein the plurality of structural support members includes:

a front middle structural support member, oriented about vertically, and disposed on a front of the container and on a first side of the container, and extending from a top portion of the container through a middle portion of the container into a bottom portion of the container;

a back middle structural support member, oriented about vertically, and disposed on a back of the container and on the first side of the container, and extending from a top portion of the container through a middle portion of the container into a bottom portion of the container;

a bottom structural support member, oriented horizontally and substantially laterally, disposed on a front of the container and in a bottom portion of the container;

a bottom middle structural support member, oriented horizontally and substantially perpendicular to the bottom structural support member, wherein an end of the bottom structural support member is joined to an end of the bottom middle structural support member; and

wherein:

at least part of the front middle structural support member is in contact with at least part of the back middle structural support member; and

a lower portion of the front middle structural support member is spaced apart from a lower portion of the back middle structural support member by a reinforcing seal that is formed by sealed portions that are bounded by edges that are shared with the bottom portions of front middle structural support member and the back middle support member and a middle portion of a bottom middle structural support member, on at least the first side, such that each reinforcing seal has an overall shape that is a substantially triangular shape.

2. The container of claim 1 , wherein 35-90% of an overall length of the front middle structural support member is in contact with at least 35-90% of an overall length of the back middle structural support member.

3. The container of claim 1 , wherein 50-90% of an overall length of the front middle structural support member is in contact with 50-90% of an overall length of the back middle structural support member.

4. The container of claim 1 , wherein:

the lower portion of the front middle structural support member forms 15-50% of an overall length of the front middle structural support member; and

the lower portion of the back middle structural support member forms 15-50% of an overall length of the back middle structural support member.

5. The container of claim 1 , wherein:

the lower portion of the front middle structural support member forms 25-50% of an overall length of the front middle structural support member; and

the lower portion of the back middle structural support member forms 25-50% of an overall length of the back middle structural support member.

6. The container of claim 1 , wherein the lower portion of the front middle structural support member is spaced apart from the lower portion of the back middle structural support member by a varying spaced apart distance that increases toward the bottom of the container.

7. The container of claim 6 , wherein the lower portion of the front middle structural support member is spaced apart from the lower portion of the back middle structural support member by a largest spaced apart distance that is:

larger than a largest cross-sectional dimension of the front middle structural support member at its lower end; and

larger than a largest cross-sectional dimension of the back middle structural support member at its lower end.

8. The container of claim 6 , wherein the lower portion of the front middle structural support member is spaced apart from the lower portion of the back middle structural support member by a largest spaced apart distance that is:

larger than any cross-sectional dimension of the front middle structural support member; and

larger than any cross-sectional dimension of the back middle structural support member.

9. The container of claim 6 , wherein the lower portion of the front middle structural support member is spaced apart from the lower portion of the back middle structural support member by a largest spaced apart distance that is 0.5-10.0 centimeters.

10. The container of claim 6 , wherein the lower portion of the front middle structural support member is spaced apart from the lower portion of the back middle structural support member by a largest spaced apart distance that is 1.0-5.0 centimeters.

11. The container of claim 1 , wherein, in a lower half of the container, the front middle structural support member is symmetrical with the back middle structural support member with respect to a plane that separates the container into a front half and a back half.