Patent ID: 6599225
Filing Date: 2003-07-29
Classification: B31B

Abstract:
A method of closing a bottom of a container against leakage of contents out of the container through the bottom thereof or ingress of foreign material into the container through the bottom thereof, comprising the steps of:providing a container blank which includes first, second, third, and fourth side panels and a fifth side sealing panel, each of said panels including first and second opposite side edges and first and second opposite ends, said panels being disposed in side-by-side relationship and folded along their respective side edges, with said fifth panel overlying and bonded to said first side edge of said first panel, to define an open-ended tubular container of generally rectangular cross-section in which each of said side panels includes an inside surface facing inwardly of the folded container and an outside surface facing outwardly of said folded container, the outer surfaces of the blank bearing a heat sealable material, said folded blank further defining top and bottom ends of said open-ended container, said bottom end of said first panel including a first flap extending between said opposite side edges of said first panel and being integrally formed with said bottom end of said first panel, said bottom end of said second panel including a second flap integrally formed with said bottom end of said second panel and being disposed centrally between said opposite side edges of said second panel, said second flap being of a length less than the distance between said opposite side edges of said second panel and being substantially centered between said opposite side edges of said second panel, said bottom end of said third panel including a third flap extending between said opposite side edges of said third panel and being integrally formed with said bottom end of said third panel, said first and third flaps being substantially geometrically identical to one another, said bottom end of said fourth panel including a fourth flap integrally formed with said bottom end of said fourth panel and being disposed centrally between said opposite side edges of said fourth panel, said fourth flap being of a length less than the distance between said opposite side edges of said fourth panel, said second and fourth flaps being substantially geometrically identical to one another, first fold lines extending substantially between the opposite side edges of each of said panels at a location spaced apart from, but adjacent to, the respective flaps of said panels, said first fold lines being aligned substantially equidistant from their respective flaps, second and third fold lines adjacent the bottom end of said second panel, said second fold line extending diagonally between proximate the juncture of said first fold line of said second panel with one of the opposite side edges of said second panel and the approximate midpoint of the length of said second flap, and said third fold line extending diagonally between proximate the juncture of said first fold line of said second panel with the other of the opposite side edges of said second panel and the approximate midpoint of the length of said second flap, fourth and fifth fold lines adjacent the bottom end of said fourth panel, said fourth fold line extending diagonally between proximate the juncture of said first fold line of said fourth panel with one of the opposite side edges of said fourth panel and the approximate midpoint of the length of said fourth flap, and said fifth fold line extending diagonally between proximate the juncture of said first fold line of said fourth panel with the other of the opposite side edges of said fourth panel and the approximate midpoint of the length of said fourth flap, a sixth fold line extending substantially transversely of said second flap at a location proximate the midpoint of the length of said second flap, a seventh fold line extending substantially transversely of said fourth flap at a location proximate the midpoint of the length of said second flap, an eighth fold line extending parallel to said first fold line extending substantially between the opposite side edges of said first panel, said eighth fold line extending between said bottom end of said first panel and said first flap, ninth and tenth fold lines extending parallel to said first fold line extending substantially between the opposite side edges of said second panel, said ninth fold line extending between said bottom end of said second panel and said second flap from a first end of said second flap to a juncture of said second, third and sixth fold lines, said tenth fold line extending between said bottom end of said second panel and said second flap from the juncture of said second, third and sixth fold lines to a second end of said second flap, an eleventh fold line extending parallel to said first fold line extending substantially between the opposite side edges of said third panel, said eleventh fold line extending between said bottom end of said third panel and said third flap, twelfth and thirteenth fold lines extending parallel to said first fold line extending substantially between the opposite side edges of said fourth panel, said twelfth fold line extending between said bottom end of said fourth panel and said fourth flap from a first end of said fourth flap to a juncture of said fourth, fifth and seventh fold lines, said thirteenth fold line extending between said bottom end of said fourth panel and said fourth flap from the juncture of said fourth, fifth and seventh fold lines to a second end of said fourth flap, whereby the bottom ends of said first and third panels are substantially identical with respect to the fold lines associated therewith, and said bottom ends of said second and fourth panels are substantially identical with respect to the fold lines associated therewith, applying a pressure against the outside surface of each of said second and fourth flaps, said pressure bending said second flap along the sixth, ninth and tenth fold lines thereof and the fourth flap along the seventh, twelfth and thirteenth fold lines thereof and forcing said second and fourth flaps inwardly of said container toward respective positions wherein said second and fourth flaps overlie one another, and simultaneous inward folding of said second and fourth panels along their respective first fold lines and along the second and third fold lines of said second panel and along the fourth and fifth fold lines of said fourth panel to define a generally triangular folding of said flap and said second panel and of said flap and said fourth panel, said folding defining an apex of each of said folded flap and bottom panels of each of said second and fourth panels, said apexes being disposed centrally of the bottom of said container when said folding is completed, at least partly simultaneously applying a pressure against the outside surface of each of said bottom ends of said first and third panels to fold said panels inwardly of said container along their respective first fold lines, said folding of said bottom ends of said first and third panels following in time the infolding of said flaps and bottom ends of said second and fourth panels whereby said second and fourth flaps of said second and fourth panels engage the infolded second and fourth flaps of said second and fourth panels and capture said infolded second and fourth flaps between said first and third flaps of said first and third panels, thereafter, folding said first flap along said eighth fold line, said third flap along said eleventh fold line, said second flap along said ninth and tenth fold lines and said fourth flap along said twelfth and thirteenth fold lines flat against the outside surface of one of said first and third panels, sealing said folded flaps to at least one outside surface of said one of said first and third panels to close the bottom of said container.