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A method and apparatus for sealing a bag made of a polymeric material by applying heat activated layers on different portions of the bag, wherein the first adhesive layer and the second adhesive layer have respective heat activation temperatures below the softening point temperature of the polymeric

A method and apparatus for sealing a bag made of a polymeric material by applying heat activated layers on different portions of the bag, wherein the first adhesive layer and the second adhesive layer have respective heat activation temperatures below the softening point temperature of the polymeric material; creasing the bag along a fold line, applying heat at a temperature below the softening point temperature of the polymeric material to activate the first adhesive layer and the second adhesive layer to adhesive states after the bag has been filled with contents; and folding the bag to form an adhesive-to adhesive seal by contact between the heat activated first adhesive layer and the heat activated second adhesive layer.

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1. A machine for sealing a bag of the type including a flap which is sealed against a front-panel of the bag to close the bag, the flap and a portion of the front-panel to which the flap is sealed each including a portion coated with heat activated adhesive, the machine comprising: a bag sealing arr

1. A machine for sealing a bag of the type including a flap which is sealed against a front-panel of the bag to close the bag, the flap and a portion of the front-panel to which the flap is sealed each including a portion coated with heat activated adhesive, the machine comprising: a bag sealing arrangement including, a hot air manifold including a hot-air input port, a first surface including a first set of openings through which hot air is directed to the flap and a second surface disposed at an angle greater than 10 b degrees to the first surface, and including a second set of openings through which hot air is directed to the portion of the front-panel to which the flap is sealed,a guide which guides the flap past the first set of openings while the front-panel is guided by the second set of openings, the guide being configured to fold and direct the flap against the front-panel to place the adhesive of the flap in contact with the adhesive of the front-panel, anda pressure applicator which forces the flap against the front-panel to facilitate adhesion of the flap to the front-panel; anda bag conveyor which engages the bag near the flap to convey an open bag into and through the bag sealing arrangement to facilitate the adherence of the flap to the front-panel by the bag sealing arrangement. 2. The machine of claim 1, wherein the hot air manifold comprises: a side wall having a plurality of openings, the side wall including at least a rectangular wall portion;a top wall including a plurality of openings, and joined to the side wall at approximately a 90 degree angle, the top wall including a first rectangular portion laying in a first plane and a second portion joined to the first portion laying in a second plane which forms an angle greater than 0 degrees with the first plane;a bottom wall joined to the side wall at approximately a 90 degree angle;a rear wall joined to each of the top and bottom walls at approximately 90 degree angles;a first and second end wall which are joined to all of the walls; andan inlet duct which is joined to at least one of the bottom or side walls or end walls to provide an air flow path from the inlet duct into the manifold and through the openings in the side and top walls. 3. The machine of claim 2, wherein the bag conveyor comprises 2 opposed belts for engaging the bag. 4. The machine of claim 3, wherein the pressure applicator includes 2 opposed belts which cooperate to force the flap against the front-panel. 5. The machine of claim 4, further comprising a pressurized hot air source coupled to the inlet duct. 6. The machine of claim 1, wherein the hot air manifold comprises: three planar, rectangular side walls, wherein one of the side walls includes a plurality of air-flow ports;a top wall having a first rectangular, planar portion and a second planar portion, the portions being non-coplanar and each have a plurality of air-flow ports;two end walls, wherein the walls are joined to form an enclosure having a rectangular cross-section, taken perpendicular to the side walls, which is uniform in area between the rectangular side walls and the first planar portion, and is non-uniform in area between the rectangular side walls and the second planar portion; andan air inlet conduit joined to a portion of the manifold without air-flow parts, the air inlet providing a passageway for air through the air inlet and into the manifold. 7. The machine of claim 6, wherein the bag conveyor comprises 2 opposed belts for engaging the bag. 8. The machine of claim 7, wherein the pressure applicator includes 2 opposed belts which cooperate to force the flap against the front-panel. 9. A machine for sealing a bag including a flap which is sealed against a panel of the bag to close the bag, the flap and a portion of the panel to which the flap is sealed each including a portion with heat activated adhesive, the machine comprising: a folder extending from a leading end to a trailing end, the folder including a portion configured to contact the flap as the bag moves past the folder in a direction from the leading end toward the trailing end, the portion extending downwardly in a direction from the leading end toward the trailing end; anda manifold including an inlet configured to receive a heated fluid, a back wall located proximate the panel as the bag moves past the manifold in the direction from the leading end of the folder toward the trailing end of the folder, the back wall including a plurality of apertures through which heated fluid is directed towards the panel, the manifold also including a top wall including a plurality of apertures through which heated fluid is directed toward the flap, the top wall including a portion extending downwardly in the direction of movement of the bag, the manifold being located lower than at least a portion of the folder, the portion of the top wall of the manifold extending downwardly being located between the leading end and the trailing end of the folder. 10. The machine of claim 9, wherein the manifold further comprises a front wall opposite the back wall, the front wall including a first portion extending parallel with the back wall and a portion extending from the first portion toward the back wall. 11. The machine of claim 9, wherein the back wall extends downwardly from a first end proximate the top wall to a second end, the back wall including a first projection projecting toward the bag proximate the first end and a second projection projecting toward the bag proximate the second end. 12. The machine of claim 9, further comprising a pressure applicator which forces the flap against the panel to facilitate adhesion of the flap to the panel; and a bag conveyor which engages the bag near the flap to convey an open bag to the folder. 13. The machine of claim 12, wherein the bag conveyor comprises 2 opposed belts for engaging the bag. 14. The machine of claim 12, wherein the pressure applicator includes 2 opposed belts which cooperate to force the flap against the panel. 15. The machine of claim 9, further comprising a pressurized hot air source coupled to the manifold and configured to provide pressured hot air to the inlet of the manifold. 16. A machine for sealing a bag of the type including a flap which is sealed against a panel of the bag to close the bag, the flap and a portion of the panel to which the flap is sealed each including a portion coated with heat activated adhesive, the machine comprising: a folder including a tapered portion between a leading end and a trailing end tapering from a maximum height proximate the trailing and to a minimum height proximate the leading end, the folder configured to fold the flap over toward the panel; anda manifold including an interior chamber, an inlet through which the manifold is configured to receive heated fluid into the interior chamber, a top wall including a plurality of apertures through which heated fluid is dispensed from the manifold, the top wall including a first planar portion and a second portion extending at a non-zero angle from the first planar portion, the second portion being located below a portion of the tapered portion of the folder, the manifold also including a back wall including a plurality of apertures through which heated fluid is dispensed from the manifold toward a portion of the panel of the bag. 17. The machine of claim 16, wherein the first planar portion of the top wall is coupled to the back wall at an approximately 90° angle. 18. The machine of claim 16, wherein the manifold further includes a front wall coupled to the top wall distal from the back wall and extending downwardly from the top wall at an approximately 90° angle; and wherein the front wall includes a first portion extending generally parallel with the back wall and a second portion extending from the first portion angularly toward the back wall. 19. The machine of claim 16, wherein the manifold further includes a first flange extending from the back wall proximate the top wall toward the bag and a second flange extending from the back wall distal from the top wall toward the bag.