Gussetted package, method and apparatus

A flexible gussetted package formed from at least one thickness of a continuous web of substantially constant thickness flexible packaging material and at least one discrete strip of substantially constant thickness flexible material, having a closed body with opposite ends and at least one package body end seal, characterized by,

• a) front and rear package faces and at least one gussetted side extending between said front and rear faces,
• b) a repeatably openable and reclosable interlocking seal operative to open and close said package body to provide and prevent respectively access to the package interior, said reclosable interlocking seal extending transversely across said package body through said front and rear faces and said at least one gussetted side of said package, and comprising in combination, inner and outer interlocking portions, the inner and outer portions of said seal in at least said front and rear faces of said package each comprising one thickness of said flexible packaging material secured to said at least one discrete strip of substantially constant thickness flexible material, said at least one strip having length and width, said strip width defining the strip ends, said strip length having top and bottom edges and being greater than said strip width, said at least one strip being secured to said packaging material along the strip top edge and being substantially unsecured along its bottom edge.

A method of making a flexible gussetted package formed from a continuous web of substantially constant thickness packaging material characterized by having front and rear faces and at least one gussetted side extending between said front and rear faces, a repeatably openable and reclosable interlocking seal operative to open and close said package body to provide and prevent respectively access to the package interior, said reclosable interlocking seal extending through said front and rear faces and at least one gussetted side of said package and comprising in combination, inner and outer interlocking portions, the inner and outer portions of said seal in at least said front and rear faces of said package each comprising one thickness of said flexible packaging material secured to at least one discrete strip of substantially constant thickness flexible material, consisting of the steps of,

• a) transporting in lengthwise direction a web of flexible packaging material of selected width and indeterminate length having at least one thermoformable strip of a length substantially greater than the strip width affixed to the web with the strip length oriented transversely to the running length of the film at package length intervals,
• b) passing said film over a forming collar and around a cylindrical forming tube and forming a longitudinally sealed cylindrical tube of packaging film with the said at least one thermoformable strip inside the film tube, and with the surface of the said at least one strip not secured to the film being in facing relationship within the tube,
• c) moving the film tube past a gusseting tool to provide a pair of opposite side gussets in the tube,
• d) moving the portion of the gussetted tube within which the strip is disposed between a pair of spaced apart heated male and female forming dies,
• e) moving said dies toward one another to press the face of the said at least one strip not secured to the film against itself to form two apposed strip faces extending at least partly across the film tube, and continuing to move said dies toward one another into mating position and forming the central part of the strip extending across the film tube into the recess of said female die to form the tip of an arrowhead shape of the reclosable seal,
• f) moving toward one another into closed position a pair of interlock forming heated dies positioned at opposite sides of the female die to press portions of the margins of the strip immediately adjacent to the central part of the strip inward against one another to complete the inner male and outer female parts of the reclosable interlocking seal held between the female die and the pair of interlock forming heated dies while partially retracting the male die, and
• g) fully retracting the male and female dies to their initial positions.

Apparatus for making a gussetted package having a reclosable interlocking seal including interfitting male and female parts and snap detents, and end seals at opposite ends of the package, comprising in combination,

• a) means for transporting in lengthwise direction a web of flexible packaging material of selected width and indeterminate length having thermoformable strips of a length substantially greater than the strips width, said strips being affixed to the web with the strips lengths oriented transversely to the running length of the film at package length intervals,
• b) a pair of spaced apart heated male and female dies for partly forming the inner and outer separable portions of the reclosable interlocking seal with the inner portion fitted within the outer portion,
• c) a forming collar and means for moving the film over said forming collar and around a cylindrical forming tube and forming a longitudinally sealed cylindrical tube of packaging film with the thermoformable strips inside the film tube and with the surfaces of the strips not secured to the film being in facing relationship within the tube,
• d) gusset forming tooling for forming a pair of opposite side gussets in said cylindrical tube, said film moving means being effective to move the portion of the gussetted tube within which the strips are disposed into position between said pair of spaced apart heated male and female dies,
• e) male and female dies moving means effective when actuated in a first way for moving said male and female dies toward one another to press the faces of the strips not secured to the film against one another to form two apposed strips faces extending at least partly across the film tube, and effective for continuing to move said dies toward one another into mating position and forming the central part of the strips extending across the film tube into the recess of said female die to form the tip of an arrowhead shape of the reclosable interlocking seal, said male and female dies moving means when actuated in a second way being effective to partially retract said male die, and being effective when actuated in a third way to fully retract said male and female dies to their initial positions,
• f) a pair of spaced apart interlocking seal completing heated dies disposed at opposite sides of said female die and having open and closed positions, said interlocking seal completing dies being effective when closed to press portions of the margins of the strips immediately adjacent to the central part of the strip inward against one another to form the inturned base of the arrowhead shape in the inner and outer portions of the reclosable interlocking seal and hold the seal within the female die, and said interlocking seal completing dies being effective when opened to release the formed seal from the said female die, and
• g) operating means actuatable for moving said interlocking seal completing heated dies between said open and closed positions.

Apparatus for making a reclosable interlocking seal having a female outer part, a male inner part and snap detents, for a resealable gussetted package having front and back faces and at least one side gusset, the package being formed from a longitudinally sealed gussetted cylindrical tube of packaging film with at least one thermoformable strip secured to the film inside the tube and with the surface of said at least one strip not secured to the film in facing relationship within the tube, comprising,

• a) a pair of spaced apart heated male and female dies,
• b) means for moving the portion of the gussetted tube within which said at least one strip is disposed between said pair of spaced apart heated male and female dies,
• c) means effective when actuated in a first way for moving said male and female dies toward one another to press the faces of the strips not secured to the film against one another to form apposed strip faces extending at least partly across the gussetted film tube, and effective for continuing to move said dies toward one another into mating position to form the central part of the strip extending across the film tube into the recess of said female die to form the tip of an arrowhead shaped reclosable seal in the front and back faces and the included gussets, said means for moving said male and female dies toward one another also being operative when actuated in a second way to move said male and female dies away from one another,
• d) a pair of interlock seal completing and detent forming heated dies positioned at opposite sides of the female die and having open and closed positions which when in closed position are operative to press portions of the margins of the strip immediately adjacent to the central part of the strip inward against one another to form the inturned base of the arrowhead shape in the inner and outer portions of the reclosable interlocking seal held within the female die, and operative to form detents in at least a portion of the margins of the strip next remote from the inturned base of the arrowhead shaped reclosable seal,
• e) means for moving toward one another into closed position said pair of interlock seal completing heated dies positioned at opposite sides of said female die effective to complete the inner male and outer female parts and snap detents of the reclosable interlocking seal held between said female die and said pair of interlock seal completing heated dies.