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A flat bottom, stand-up bag and a method of manufacturing the bag is provided. The bag includes a bottom wall, opposing front and rear walls and two side walls. The side walls connect the front and rear walls and the bottom wall is connected to the other walls at their lower edge. The bag preferably

A flat bottom, stand-up bag and a method of manufacturing the bag is provided. The bag includes a bottom wall, opposing front and rear walls and two side walls. The side walls connect the front and rear walls and the bottom wall is connected to the other walls at their lower edge. The bag preferably incorporates a continuous polymer web material forming the front wall and rear wall of the bag, as well as the bottom wall. The side walls include gussets and a triangular base portion formed at the intersection between the bottom wall and the side walls.

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1. A method of forming a bag having a bottom wall, opposing front and rear walls and two sidewalls, the method comprising the steps of: a) providing two adjacent webs of material, the adjacent webs continuously formed with one another and folded along one edge, defining a fold line, two parallel web

1. A method of forming a bag having a bottom wall, opposing front and rear walls and two sidewalls, the method comprising the steps of: a) providing two adjacent webs of material, the adjacent webs continuously formed with one another and folded along one edge, defining a fold line, two parallel web extending from the fold line with two projected ends positioned opposite the fold line;b) moving the webs in a forming direction that is transverse to their direction of extension from the fold line;c) providing an inwardly directed bottom gusset fold along the fold line, such that the fold line is positioned between the web layers, wherein the bottom gusset fold defines a bottom edge of the bag;d) joining the web layers along a first seal line transverse to the inwardly directed bottom gusset fold and transverse to the forming direction, the first seal line extending inwardly from the bottom edge;e) joining the web layers along a second seal line transverse to the inwardly directed bottom gusset fold, the second seal line extending inwardly from the bottom edge, and the second seal line spaced from and parallel to the first seal line;f) separating a portion of the web material defined between the first seal line and the second seal line;g) forming an inwardly directed side gusset fold along both the first and second seal lines, such that the inwardly directed side gusset folds are positioned between the web layers and transverse to the bottom gusset fold, the side gusset folds defining sidewalls for and extending from the bottom edge of the bag; andh) the forming of the side gusset folds and the inwardly directed bottom gusset fold combining to form a pair of folded triangular base portions, the folded triangular base portions continuously formed with and connected to the inwardly directed bottom gusset fold, each folded triangular base portion extending upwardly from the bottom gusset fold and one folded triangular base portion positioned adjacent each of the inwardly directed side gusset folds, the folded triangular base portions sealed along their height to the adjacent first and second seal lines and positioned inwardly of the side walls and the seal lines. 2. The method as in claim 1, further comprising the steps of: forming a continuous web, and folding the continuous web along the fold line to form the two adjacent webs. 3. The method as in claim 1, wherein the folded triangular base portions comprise an open folded portion positioned between the bottom gusset fold and the first and second seal lines. 4. The method as in claim 1, wherein the joining steps occur incrementally during movement of the webs in the machine direction. 5. The method as in claim 4, wherein the formation of the folded triangular base portions occurs sequentially after the joining steps for the first and second seal lines. 6. The method as in claim 1, wherein the material webs are formed from a polymer material. 7. The method as in claim 6, wherein the polymer material is heat weldable and the joining steps for the first and second seal lines are conducted by heat sealing the adjacent web layers together. 8. The method as in claim 6, wherein the polymer material comprises high density polyethylene. 9. The method of claim 1, further comprising the step of spacing the web material relative to one another prior to providing the inwardly directed gusset folds. 10. A method of forming a bag having a bottom wall, and a plurality of upstanding walls, including a front wall, a rear wall and a pair of opposing sidewalls, the upstanding walls joined with and extending from the bottom wall, and the walls defining a storage volume there between, the method comprising the steps of: providing a continuous polymer web;providing a fold line within the polymer web by positioning two web layers parallel and adjacent one another, the web layers integrally formed with one another, extending from the fold line and defining two projected layer ends opposite the fold line, the parallel web layers forming at least front and rear walls of the bag to be formed;moving the web in a machine direction parallel to the direction of the fold line and transverse to the projected extension of the web layers;forming a bottom gusset fold by directing the fold line transverse to the machine direction and between the adjacent web layers, the bottom gusset fold forming a continuous bottom wall, the bottom wall continuously formed with the front and rear walls of the bag to be formed;sealing the web layers along spaced first and second sealing lines, the sealing lines directed transverse to the machine direction, and the sealing lines each extending across the bottom gusset fold;separating the portion of the layers between the spaced first and second sealing lines to form a bag blank;folding the web layers adjacent each of the first and second sealing lines to create inwardly directed side gusset folds within the bag blank, the gusset folds positioned transverse to the bottom gusset fold and the side gusset folds forming the sidewalls for the bag; andforming folded triangular base portions at a base of and inwardly of the sidewalls, the folded triangular base portions continuously formed with the bottom wall, joined to the adjacent sealing lines and positioned along the side gusset folds. 11. The method as in claim 10, wherein the folded triangular base portions comprise an open folded portion, wherein the oven fold is positioned between the bottom fold and the sidewalls of the bag. 12. The method as in claim 11, wherein the formation of the folded triangular base portions occurs simultaneously with the folding of the web layers to form the inwardly directed side gusset folds and sequentially after the sealing and separating steps. 13. The method as in claim 10, wherein the polymer material comprises high density polyethylene. 14. The method as in claim 10, wherein the polymer material is heat weldable and the sealing step for the first and second seal lines are conducted by heat sealing the adjacent web layers together. 15. The method of claim 10, further comprising the step of spacing the web layers relative to one another prior to folding the inwardly directed gusset folds. 16. A method of forming a bag having a bottom wall, opposing front and rear walls extending from the bottom wall, two sidewalls extending from the bottom wall and connecting the front and rear walls, the walls defining a storage volume there between, the method comprising the steps of: providing a continuous polymer web;providing a fold line within the polymer web by positioning two web layers parallel and adjacent one another, the web layers integrally formed with one another, extending from the fold line and defining two projected layer ends opposite the fold line, wherein the front and rear walls of the bag are formed from the parallel web layers;moving the web in a machine direction parallel to the direction of the fold line and transverse to the projected extension of the web layers;continuously forming a bottom gusset fold by directing the fold line transverse to the machine direction and between the adjacent web layers, the bottom gusset fold defining a bottom edge of the bag and the bottom wall of the bag, the bottom gusset fold integrally formed with the two web layers projecting therefrom in a direction transverse to the machine direction;sequentially sealing the web layers and the bottom gusset fold at spaced intervals in the machine direction, the sequential sealing steps forming parallel and continuous seal lines extending from the bottom edge of the bag and transverse to the machine direction, the sequential seal lines having a portion of the web layers extending there between;separating a portion of the web layers adjacent sequential seal lines to define a bag blank, the bag blank having an open end opposite of the bottom gusset fold;defining the sidewalls of the bag by providing inwardly directed gusset folds along both seal lines within the bag blank, the side gusset folds positioned between the web layers within the bag blank and transverse to the bottom gusset fold, and the side gusset folds forming sidewalls along the seal lines within the bag blank; andforming folded triangular base portions along with the inwardly directed gusset folds, the folded triangular base members sealed at the seal lines adjacent the bottom edge of the bag, projecting inwardly from and extending along the sidewalls, the folded triangular continuously and integrally formed with the bottom wall, the base of the triangular portions serving to space the front and rear walls. 17. The method of claim 16, further comprising the step of spacing the web layers relative to one another adjacent the side seals prior to providing the inwardly directed side gusset folds.