Machine and method for manufacturing square or flat bottom bags having movable positions or stations including the use of a mandrel

In a vertically disposed apparatus for forming flat bottom bags from a continuous sleeve of material having opposed faces and sides gussetted inwardly between the opposed faces,

• means for supporting a length of the sleeve of material substantially vertically on said apparatus,
• an elongated mandrel substantially vertically disposed within the material sleeve and having relatively movable actuating and support members and operable wings connected with said members for moving said wings between extended and retracted positions in response to relative movement of said actuating and support members,
• first and second relatively movable roller means on said apparatus disposed externally of the opposed faces of the sleeve of material and operatively engageable with said mandrel for moving said wings between said expanded and retracted positions,
• cooperating means on said actuating and support members opposite said wings for engagement with said first and second roller means and for relatively moving said actuating and support members in response to relative movement of said first and second roller means to cause the operation of said wings,
• said first and second roller means being positioned in contact with the outer surface of the opposed material faces and engaging said mandrel cooperating means in pressing contact through the material to suspend the mandrel within the material sleeve from said first and second roller means while enabling unrestricted axial movement of the material sleeve between and relative to said roller means and cooperating means.

In an apparatus for forming a flat bottom bag from a substantially endless sleeve of material having opposed faces and gussetted sides connecting the same,

• transverse seal forming means for completing a transverse seal on the sleeve of material connecting the opposed faces and including the gussetted sides in the area of the transverse seal,
• a mandrel including interior means movable interior of the sleeve of material for opening the gussetted sides and opposed faces thereof to form a flat bottom for a bag in the area of and including said transverse seal, said mandrel further including actuating means for operating said interior means
• said interior means being movable from an inactive to an active position to flatten the open gussetted sides in the area of said transverse seal to crease the same between the opposed faces of the sleeve so that the gussetted sides form interior flaps for sealing to said flat bottom,
• and means on said apparatus exterior of the sleeve of material and engaging said actuating means through the faces of the sleeve interposed therebetween for moving the interior movable means between its inactive and active positions within and relative to the sleeve.

In an apparatus for forming a flat bottom bag having a double seal from a sleeve of material having opposed faces and gussetted sides,

• means for engaging the opposed faces of the sleeve to form thereon a transverse seal and to include in said transverse seal the gussetted sides
• interior means including wing-like means movable and operable within the sleeve to open the gussetted sides and to press the same against the transverse seal and interior portions of the opposed faces while opening the sleeve to flatten the same and the gussetted sides in the area of the transverse seal, said interior means further including relatively movable actuating means for operating said wing-like means,
• seal means engaging an area of the sleeve at which the gussetted sides are flattened and pressing against the outer surface of the opposed faces with said interior means forming an abutment against which the opposed faces are pressed,
• said seal means sealing the opposed faces and gussetted sides pressed against each other to seal the same together to form a double thick bag bottom,
• and cooperating means on said apparatus adjacent the outer surface of the sleeve and engageable with said interior means through the sleeve of material for supporting said interior means within the sleeve and for operating said members for forming said interior abutment while permitting lengthwise movement of the sleeve between and relative to said cooperating means and said interior means.

In an apparatus for forming a reinforced flat bottom bag from a sleeve of material having opposed faces and gussetted sides therebetween,

• transverse seal means for connecting the opposed faces of the sleeve along a transverse portion thereof and including in said seal the gussetted sides adjacent thereto,
• means interior of the sleeve of material operable for opening the sleeve to expand the side gussets and relatively space apart the opposed faces to form a flat bottom for a bag in the area of and including said transverse seal and cause the formation of side gusset flaps, said means interior of the sleeve further including actuating means
• means exterior of the sleeve engaging said actuating means through the faces of the sleeve interposed therebetween for operating said means interior of the sleeve,
• and gusset sealing means on said apparatus pivotally movable with the operation of said interior means between an inactive position remote from the sleeve of material and an active position in which said gusset sealing means is pivotted inwardly with respect to said interior means for engaging the outer surface of said flat bottom and pressing the same against said side gusset flaps such that said interior means defines an abutment interior of the sleeve for sealing said flat bottom to preselected portions of said side gusset flaps to form a reinforced bag bottom on the sleeve of material.

In an apparatus for forming flat bottom bags from a substantially endless web of gussetted tubular material having opposed substantially flat faces and longitudinally gussetted sides,

• a mandrel disposed within the tubular material having relatively movable actuating members and extensible wings movable from retracted inoperative to expanded operative positions to cause the tubular material to open at its gussetted sides with the opposed faces of the material remaining substantially flat,
• said actuating members each being engaged with said wings to move the wings between their operative and inoperative positions in response to the relative movement of said actuating members,
• operating means external of the tubular material and in operative cooperation with said actuating members through the material,
• said operating means being operable to cause said actuating members to move relative to each other,
• means on said apparatus for forming a transverse end closure seal on the tubular material to include within the seal the gussetted sides of the material,
• means to sever the material adjacent the transverse seal to form a skirt on the material beyond said transverse seal,
• gripping means on said apparatus operable for gripping said skirt on the material and to move the material along said apparatus and relative to said mandrel,
• said wings flattening in said expanded position against the interior surfaces of the side gussets sealed at said transverse PG,41 end closure seal to flatten the same against said transverse end closure seal to form flaps of the gussets and to open the gussetted sides of the material to form a flat bottom for a bag,
• and flap sealing means on said apparatus movable to and from an active position in sealing engagement with the external surface of the flat bottom of the bag to seal the flat bottom engaged by said flap sealing means with preselected portions of the flaps formed by said wings.

A method of making a reinforced flat bottom plastic bag comprising the steps of:

• providing a sleeve having opposed faces and sides gussetted inwardly between the opposed faces,
• closing one end of the sleeve with a seam to seal the opposed faces together with the gussetted sides therebetween,
• providing a means exterior of the sleeve and wing-like means interior of the sleeve,
• opening the gussetted sides by operating said wing-like means by said means exterior of the sleeve through the faces of the sleeve interposed therebetween such that said wing-like means flatten the gussetted sides against the opposed faces to form flaps of the gussetted sides that have folds lying in overlapping relationship with the opposed faces while moving together the sleeve and said wing-like means included within the sleeve,
• and securing together preselected portions of the flaps and the overlapping sides and faces to form a flat bottom by pressing preselected portions of the flaps and the overlying sides and faces together at the preselected portions and heat sealing to secure the same together thereat.

A method of forming a flat bottom reinforced plastic bag from a continuous sleeve of material having opposed faces and gussetted sides,

• transversely sealing the sleeve to hold the gussets in place between the opposed faces in the transverse seal and to define a closed bottom of the bag,
• providing a means exterior of the sleeve and a bag opening means interior of the sleeve,
• moving the sleeve of material along with said bag opening means enclosed within it while operating the bag opening means within the sleeve by said means exterior of the sleeve through the faces of the sleeve to cause the bag opening means to open the bottom of the bag to form flaps of the side gussets,
• moving a flat heat seal into and out of engagement with the exterior surfaces of the sleeve while pressing the side gusset flaps against the interior of the opposed faces to cause the flaps and the faces to be heat sealed together at preselected portions thereof,
• and moving the bag sleeve off of the enclosed means after moving the flap seal out of engagement with the sleeve.