Abstract:
A square bottom plastic bag is designed to stand upright when opened. The bags are constructed with open tops, side handle openings and attached headers or with t-shirt style handles. The bags are produced in registered bag stacks and include means for adhering a rear surface of one bag to a front surface of a subsequent bag to make the bags self-opening when used with a dispensing rack. The headered bags have tear-off headers or headers with weakened areas that will rupture upon dispensing. The t-shirt bags have apertures through the handles to suspend the bags on a rack or a header attached above the handles. The bags have detachable or rupturable center tabs. The bags are registered with hot pins or cold stakes through an upper portion of the bags or bag handles. The bags have openings, microperforations, or are formed of porous material to dissipate heat or moisture.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention pertains to plastic bags and methods of manufacturing them. More particularly, the invention relates to square bottomed bag stacks supplied with a detachable header portion for suspending the bag stack as well as t-shirt style handle bags.  
       BACKGROUND OF THE INVENTION  
       [0002]     Plastic bags have replaced paper bags for many applications in recent years based upon the ease and economics with which they can be manufactured. However, at present, paper bags are still favored for certain applications. Paper bags can easily be constructed with a completely flat bottom and can be made to stand up without a supporting rack both when empty and when filled. Also, paper bags tend to be somewhat porous and “breathable” and thus more desirable for use with items such as hot food products. For these reasons, paper bags have dominated such industries as fast food delivery and other applications in which it is important to be able to easily position articles within the bag. Paper bags, on the other hand, have other problems. For example, strong handles are not easily attached to paper bags, the bags become weakened with moisture, they are heavy, bulky and require wood as raw material. Plastic bags, on the other hand, are more durable, more compact and light weight, stronger, impervious to moisture and can easily be made with strong handles.  
         [0003]     Various designs have been developed in attempts to provide a practical, breathable, square bottomed plastic bag that will stand up when opened for filling and remain upright when filled. U.S. Pat. No. 6,286,681 issued to Wilfong, Jr. et al. is directed to a ventilated plastic bag embodying closely spaced micro-perforations that extend through the wall sections to provide ventilation to the interior food carrying area. These perforations allow the bag to be used for carrying hot food items without weakening the strength regions of the bag. The closed bottom area of the bag may be formed by heat-sealing of the film material, but may also include corner or angle seals to define a square bottom on the bag.  
         [0004]     U.S. Application Publication No. 2002/0110290 by Gebhardt discloses a plastic bag with randomly placed arcurate vent pairs. The bags described in this publication are made from a plastic tubing or sheeting stock. The bag may also include a handle aperture and the bag may include square-bottomed seals on gusseted bags. In the preferred embodiment of the receptacle described, vents are cut into the material of the receptacle that can accommodate, store, and transport fresh hot foods to provide a breathable element desired for the bags.  
         [0005]     U.S. Pat. No. 6,319,184 issued to DeMatteis is directed to an apparatus and process for producing cold seal in plastic bags. The bags described may be of a semi-flat-bottom type and may have hand holes to form handles in the upper portion of the bags. U.S. Pat. No. 6,113,269 issued to DeMatteis discloses an automatic ventilating system for plastic bags. U.S. Pat. No. 6,095,687 issued to DeMatteis is directed to a flat bottomed plastic bag having a handle aperture. The bag described sits upright upon a bottom gusset.  
         [0006]     U.S. Pat. No. 5,149,201 issued to Benoit discloses a bag structure of a thermoplastic film material comprising front and rear bag walls connected by side walls and having an open mouth top portion, said open mouth portion being characterized by having handles located at opposite end regions thereof, said handles being of two films as a result of being integral extensions of said front rear and gusseted side walls, said bag having a bottom wall planarly extensible so as to form a rectangle with at least no substantial excess film outside of the bulk volumetric capacity of said bottom region of said bag. This invention also provides a method and system for preparing flat bottom thermoplastic sacks comprising process steps and means for forming a tube of thermoplastic film, collapsing said tube while forming two oppositely disposed gussets therein, forming two pairs of diagonal sealed seams in the gussets, forming a transverse sealed seam across the tube along a line which includes the inboard ends of the diagonal seams and forming pre-weakened transverse lines closely adjacent to said transverse sealed seam or forming a severing line along this line, removing the four double triangular regions bounded by the diagonal seams, the transverse seams and the side edges of the tube and collecting the resulting structures either while still interconnected or by stacking the severed sacks. The final structure can have handles or it can be handleless.  
         [0007]     U.S. Pat. No. 5,165,799 issued to Wood describes flexible square bottom bags which include side gusset panels having central inwardly oriented fin seams and which are sealed adjacent their lowermost corners to portions of the front and rear panels of the bags and wherein the entire width of the lowermost edges of the front and rear panels are sealed to thereby form bags having bottoms reinforced by triangular gusset seals at each corner and which have an outwardly oriented transverse bottom fin seam when erected.  
         [0008]     U.S. Pat. No. 5,362,152 issued to Fletcher et al. describes a T-shirt type plastic bag adapted for carrying hot foods from fast food restaurants. The bag includes front and rear wall sections, gussetted side wall sections integrally connecting the front and rear wall sections together and means connecting the bottoms of the front, rear and gussetted side wall sections together to define a closed bottom. At least a part of the front and rear wall sections are open at the tops to define a mouth portion. Laterally spaced handles are integral with the front, rear and gussetted side wall sections and extend upwardly from opposed sides of the mouth portion. Apertures extend through at least one of the wall sections for providing a path for a venting air flow from the outside of the bag and through the inside of the bag when the bag is carrying hot food.  
         [0009]     U.S. Pat. No. 5,102,384 issued to Ross et al. discloses a method of constructing a flat bottom in a plastic film tube having an open upper end, a closed lower end formed by a transverse seal, forward and rearward sides and a pair of opposing pleated sides that interconnect the forward and rearward sides. The method includes the steps of releasably engaging a lower vacuum and a lower clamp with a transverse section of the rearward side of the tube to provisionally hold the transverse section. A lateral section of the forward side is gripped and raised by an upper vacuum and an upper clamp to expose a portion of the pleated sides such that first and second pockets are formed, respectively, in the sides. The sealed lower end is drawn toward the upper end to fold the tube along first and second transverse fold lines in the forward side, along a third transverse fold line in the transverse section of the rearward side, and along fourth and fifth fold lines, respectively, in the pleated sides such that the first and second pockets are located in the pleated sides, respectively between the first and third fold lines and the lower end of the bag. Pressure is applied to the tube to form creases along the first, third, fourth and fifth fold lines, which define the perimeter of the flat bottom of the tube.  
         [0010]     U.S. Pat. No. 5,549,538 issued to Marsik describes a process for manufacturing a multi-ply square bottom bag having a front wall, a back wall, a pair of gusseted side walls, each of which join to said front and back walls. There is also formed a gusseted square bottom panel having spaced but substantially parallel gusset edges and said bottom is joined to the front, back and side walls. The bag is produced by providing a web of inner ply material and a web of outer ply material, adhesively joining said webs into a composite and forming said bag from said joined webs. The improvement relates to forming a first flap in the inner web by cutting the web so as to form a plurality of free edges and a hinge line for said flap. The hinge line is connected to the free edges so that the free edges and hinge line define the flap. Thereafter joining the inner and outer webs to form the composite web. The hinge line is generally transverse to the longitudinal axis of the web and the flap is formed in the inner web so as to be positioned adjacent the front wall and bottom wall with the hinge line at the junction thereof when said bag is formed and said flap is arranged to overlie the gusset edges in the bottom panel.  
         [0011]     It is an objective of the present invention to provide a registered bag stack with attached headers for suspension from a dispensing rack. It is an additional objective to provide a registered bag stack with integral t-shirt style handles formed in an upper portion of the bag. It is a further objective to provide square bottomed bags that will remain upright when opened in filled or unfilled condition. It is a still further objective of the invention to provide a breathable or ventilated bag suitable for use with hot food or similar items. It is yet a further objective to provide a bag stack that has the above-described features that is easily and inexpensively manufactured.  
         [0012]     While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.  
       SUMMARY OF THE INVENTION  
       [0013]     The present invention addresses all of the deficiencies of prior art square bottom bag stack inventions and satisfies all of the objectives described above.  
         [0014]     (1) A square bottomed plastic bag stack providing the desired features may be constructed from the following components. A plurality of stacked polyethylene film bags is provided. Each of the bags includes front and rear polyethylene film walls. Each of the front and rear walls have first and second side edges, a top edge and a bottom edge. Each of the bags has a pair of longitudinally oriented side gussets attached to the first and second side edges. Each of the bags has a flat, rectangular bottom formed of lower portions of the front and rear walls and lower portions of the side gussets. Each of the bags is folded inwardly at the side gussets and upwardly from either the front wall or the rear wall at a point spaced upwardly from the bottom edge, to form a flattened bag. The bags are stacked upon one another and held in registration by attachment of the bags to one another, thereby forming a registered bag stack. Each of the bags is attached at the top edges of at least one of the front and rear walls to at least one header strip. When the bags are pulled from the bag stack and opened, they will stand erect upon the flat bottom.  
         [0015]     (2) In a variant of the invention, a plurality of stacked polyethylene film bags is provided. Each of the bags includes front and rear polyethylene film walls. Each of the front and rear walls has first and second side edges, a top edge and a bottom edge. Each of the bags has a pair of longitudinally oriented side gussets attached to the first and second side edges. Each of the bags has a flat, rectangular bottom formed of lower portions of the front and rear walls and lower portions of the side gussets. Lower corners of the each side gusset are folded outwardly and together to form downward pointing triangular panels. The triangular panels are folded inwardly from the side gussets. Lower portions of the front and rear walls are folded inwardly and sealed together to form the bag bottom. The bag bottom is sealed to the side gussets adjacent upper edges of the triangular panels. The triangular panels are sealed to an upper surface of the bag bottom. Each of the bags is folded inwardly at the side gussets and upwardly from either the front wall or the rear wall at a point spaced upwardly from the bottom edge, to form a flattened bag. The bags are stacked upon one another and held in registration by attachment of the bags to one another, thereby forming a registered bag stack. When the bags are pulled from the bag stack and opened, they will stand erect upon the flat bottom.  
         [0016]     (3) In a further variant, a plurality of stacked polyethylene film bags is provided. Each of the bags includes front and rear polyethylene film walls. Each of the front and rear walls has first and second side edges, a top edge and a bottom edge. Each of the bags has a pair of longitudinally oriented side gussets attached to the first and second side edges. Each of the bags has a crease line. The crease line is parallel to the bottom edges and spaced upwardly from the bottom edges by approximately one half of a width of one of the side gussets. Each of the bags is slit from the bottom edges of the walls to the crease line at each intersection of the front and rear walls and the side gussets.  
         [0017]     Each of the bags has a flat, rectangular bottom formed of lower portions of the front and rear walls and lower portions of the side gussets. Lower corners of the each side gusset are folded outwardly to the crease line and together to form downward pointing triangular panels. The triangular panels are folded inwardly from the side gussets at the crease line. Lower portions of the front and rear walls are folded inwardly from the crease line and sealed together to form the bag bottom. The bag bottom is sealed to the side gussets adjacent the crease line and upper edges of the triangular panels. The triangular panels is sealed to an upper surface of the bag bottom. Each of the bags is folded inwardly at the side gussets and upwardly from either of the front wall and the rear wall at the crease line, to form a flattened bag. The bags are stacked upon one another and held in registration by attachment of the bags to one another, thereby forming a registered bag stack. When the bags are pulled from the bag stack and opened, they will stand erect upon the flat bottom.  
         [0018]     (4) In still a further variant, each of the bags is attached at the top edges of at least one of the front and rear walls to at least one header strip.  
         [0019]     (5) (6) In yet a further variant of the invention, the header strip is attached at the top edges of at least one of the front and rear walls by at least one perforation.  
         [0020]     (7) (8) In still another variant, the header strip has at least one hole for suspending the bags from a dispensing rack.  
         [0021]     (9) (10) In yet another variant, the header strip includes at least one weakened area. The weakened area extends from the hole to an upper edge of the header strip.  
         [0022]     (11) In a further variant of the invention, the square bottomed plastic bag stack includes means for attaching an upper portion of the rear wall of a leading one of the bags to an upper portion of the front wall of a subsequent bag in the bag stack. When the leading bag is pulled from the bag stack, the subsequent bag will cause the leading bag to open.  
         [0023]     (12) In still a further variant, the means for attaching an upper portion of the rear wall of a leading one of the bags to an upper portion of the front wall of a subsequent bag in the bag stack is selected from the group that includes glue spotting, corona treatment, pressure and corona treatment with pressure.  
         [0024]     (13) (14) In another variant, the header strips are attached to one another with at least one hot pin extending through the headers to maintain the bags in registration.  
         [0025]     (15) (16) In still another variant of the invention, the header strips are attached to one another with at least one cold stake extending through the headers to maintain the bags in registration.  
         [0026]     (17) (18) In yet another variant, at least one handle opening is provided. The handle opening extends through the front and rear walls in an upper portion of each of the bags.  
         [0027]     (19) In a further variant, the bags are formed of a porous material.  
         [0028]     (20) In still a further variant, the bags are formed of material having microperforations penetrating at least a portion of any of the bag walls and side gussets.  
         [0029]     (21) In another variant, the bags have a plurality of ventilating openings penetrating at least a portion of any of the bag walls and side gussets.  
         [0030]     (22) In still another variant, an upper seal is provided. The upper seal joins the front wall to the rear wall at the top edges of the bag walls and joins top edges of the side gussets. A U-shaped cutout is provided. The cutout commences at a first point on the upper seal. The first point is spaced from the first side edge and extends downwardly toward the bottom edges, across an upper portion of the bag walls and upwardly to a second point on the upper seal. The second point is spaced from the second side edge, thereby forming an open bag mouth and a pair of bag handles terminating at the upper seal.  
         [0031]     (23) In yet another variant, the bags are attached to one another with at least one hot pin extending through the bag handles to maintain the bags in registration.  
         [0032]     (24) In yet a further variant, the bags are attached to one another with at least one hot pin extending through the upper portion of the bag walls to maintain the bags in registration.  
         [0033]     (25) In still a further variant, the bags are attached to one another with at least one cold stake extending through the bag handles to maintain the bags in registration.  
         [0034]     (26) In another variant of the invention, the bags are attached to one another with at least one cold stake extending through the upper portion of the bag walls to maintain the bags in registration.  
         [0035]     (27) In yet another variant, the bags further comprise a pair of apertures, each of the apertures penetrating the bag handles at a point spaced downwardly from the upper seal, the apertures permitting the bag stack to be suspended from a dispensing rack.  
         [0036]     (28) In still another variant, a central tab is provided. The central tab extends upwardly from at least one of the front wall and the rear wall at the open mouth. The central tab has an opening through it for suspending the bag stack.  
         [0037]     (29) In a further variant, the central tab is attached to at least one of the front wall and the rear wall at the open mouth at a weakened area. The weakened area permits the central tab to be torn from the open mouth of the bag as the bag is removed from a dispensing rack.  
         [0038]     (30) In still a further variant, the central tab includes a weakened area. The weakened area extends from the opening to an upper edge of the central tab. The weakened area parts under pressure as the bag is removed from a dispensing rack.  
         [0039]     (31) In yet a further variant of the invention, at least one header strip is provided. The header strip is attached above the upper seal.  
         [0040]     (32) In still another variant, the header strip is attached above the upper seal with at least one perforation.  
         [0041]     (33) In still a further variant, the header strip has at least one hole therethrough for suspending the bag stack.  
         [0042]     (34) In a further variant, the header strip includes a weakened area. The weakened area extending from the hole to an upper edge of the header strip. The weakened area parting as the bag is removed from a dispensing rack.  
         [0043]     (35) A method of making a square bottomed plastic bag stack, includes the following steps. Extruding a tube of polyethylene material. Forming side gussets in the tube and flattening the tube. Cutting the flattened tube perpendicular to the side gussets to a first predetermined length, thereby forming a bag blank. The bag blank has front and rear walls, front and rear top edges, front and rear bottom edges, first and second side edges. Slitting the bag blank at intersections of the side gussets and the front and rear walls from the front and rear bottom edges upwardly for a first predetermined distance. Folding lower corners of the each side gusset outwardly and together to form downward pointing triangular panels. Folding the triangular panels inwardly from the side gussets. Folding lower portions of the front and rear walls inwardly. Sealing the front and rear wall together adjacent the front and rear bottom edges to form a bag bottom. Sealing the bag bottom to the side gussets adjacent upper edges of the triangular panels. Sealing the triangular panels to an upper surface of the bag bottom. Folding each of the bags inwardly at the side gussets and upwardly from either of the front wall and the rear wall at a point spaced upwardly from the bottom edge, to form a flattened bag. Stacking a plurality of the bag blanks in registration to form a bag stack.  
         [0044]     (36) A variant of the method of making a square bottomed plastic bag stack, includes the following steps. Extruding a tube of polyethylene material. Forming side gussets in the tube and flattening the tube. Cutting the flattened tube perpendicular to the side gussets to a first predetermined length, thereby forming a bag blank. The bag blank has front and rear walls, front and rear top edges, front and rear bottom edges, first and second side edges. Forming a crease line in each of the bag blanks. The crease line is parallel to the bottom edges and spaced upwardly from the bottom edges by approximately one half of a width of one of the side gussets. Slitting each of the bag blanks from the bottom edges of the walls to the crease line at each intersection of the front and rear walls and the side gussets. Folding lower corners of the each side gusset outwardly to the crease line and together to form downward pointing triangular panels. Folding the triangular panels inwardly from the side gussets at the crease line. Folding lower portions of the front and rear walls inwardly from the crease line. Sealing the front and rear wall together adjacent the front and rear bottom edges to form a bag bottom. Sealing the bag bottom to the side gussets adjacent the crease line and upper edges of the triangular panels. Sealing the triangular panels to an upper surface of the bag bottom. Folding each of the bag blanks inwardly at the side gussets and upwardly from either of the front wall and the rear wall at the crease line, to form a flattened bag. Stacking a plurality of the bag blanks in registration to form a bag stack.  
         [0045]     (37) A further variant of the method of making a square bottomed plastic bag stack includes the following steps. Prior to stacking the bag blanks, perforating the bag blank at a perforation line, the perforation line located at a second predetermined distance from the front and rear top edges. Cutting the bag stack above the perforation line to form a plurality of bag stack header strips. Attaching the header strips to one another to maintain the bags in registration. When the bags are pulled from the bag stack and opened, they will stand erect upon the flat bottom.  
         [0046]     (38) A still further variant of the method of making a square bottomed plastic bag stack includes the following step of cutting at least one hole in the header strips for suspending the bags from a dispensing rack.  
         [0047]     (39) Yet a further variant of the method of making a square bottomed plastic bag stack includes the step of forming at least one weakened area. The weakened area extends from the hole to an upper edge of the header strip.  
         [0048]     (40) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of attaching an upper portion of the rear wall of a leading one of the bags to an upper portion of the front wall of a subsequent bag in the bag stack. When the leading bag is pulled from the bag stack, the subsequent bag will cause the leading bag to open.  
         [0049]     (41) Another variant of the method of making a square bottomed plastic bag stack includes the step of providing a means for attaching an upper portion of the rear wall of a leading one of the bags to an upper portion of the front wall of a subsequent bag in the bag stack. The means are selected from the following group that includes glue spotting, corona treatment, pressure and corona treatment with pressure.  
         [0050]     (42) Still another variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one hot pin through the headers to maintain the bags in registration.  
         [0051]     (43) Yet another variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one cold stake through the headers to maintain the bags in registration.  
         [0052]     (44) A further variant of the method of making a square bottomed plastic bag stack includes the step of cutting at least one handle opening in the bag stack. The handle opening extends through the front and rear walls in an upper portion of each of the bags.  
         [0053]     (45) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of forming the bags of a porous material.  
         [0054]     (46) Yet a further variant of the method of making a square bottomed plastic bag stack includes the step of forming microperforations penetrating at least a portion of any of the bag walls and side gussets.  
         [0055]     (47) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of forming a plurality of ventilating opening penetrating at least a portion of any of the bag walls and side gussets.  
         [0056]     (48) Another variant of the method of making a square bottomed plastic bag stack includes the following steps. Prior to stacking the bag blanks, joining the front wall to the rear wall at the top edges of the bag walls and joining top edges of the side gussets, thereby forming an upper seal. Forming a U-shaped cutout. The cutout commences at a first point on the upper seal spaced from the first side edge and extends downwardly toward the bottom edges, across an upper portion of the bag walls and upward to a second point on the upper seal spaced from the second side edge, thereby forming an open bag mouth and a pair of bag handles terminating at the upper seal.  
         [0057]     (49) Still another variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one hot pin through the upper portion of the bag walls to maintain the bags in registration.  
         [0058]     (50) A further variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one hot pin through the bag handles to maintain the bags in registration.  
         [0059]     (51) Yet a further variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one cold stake through the upper portion of the bag walls to maintain the bags in registration.  
         [0060]     (52) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one cold stake through the bag handles to maintain the bags in registration.  
         [0061]     (53) Another variant of the method of making a square bottomed plastic bag stack includes the step of cutting a pair of apertures. Each of the apertures penetrate the bag handles at a point spaced downwardly from the upper seal. The apertures permit the bag stack to be suspended from a dispensing rack.  
         [0062]     (54) Still another variant of the method of making a square bottomed plastic bag stack includes the step of forming a central tab. The central tab extends upwardly from at least one of the front wall and the rear wall at the open mouth. The central tab has an opening through it for suspending the bag stack.  
         [0063]     (55) Yet another variant of the method of making a square bottomed plastic bag stack includes the step of forming a weakened area. The weakened area attaches the central tab to at least one of the front wall and the rear wall at the open mouth. The weakened area permits the central tab to be tom from the open mouth of the bag as the bag is removed from a dispensing rack.  
         [0064]     (56) A further variant of the method of making a square bottomed plastic bag stack includes the step of forming the central tab with a weakened area. The weakened area extends from the opening to an upper edge of the central tab. The weakened area parts under pressure as the bag is removed from a dispensing rack.  
         [0065]     (57) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of attaching a header strip above the upper seal.  
         [0066]     (58) Yet a further variant of the method of making a square bottomed plastic bag stack includes the step of attaching the header strip above the upper seal with at least one perforation.  
         [0067]     (59) Another variant of the method of making a square bottomed plastic bag stack includes the step of cutting at least one hole through the header strip for suspending the bag stack.  
         [0068]     (60) A final variant of the method of making a square bottomed plastic bag stack includes the step of forming a weakened area. The weakened area extends from the opening to an upper edge of the header strip. The weakened area parts as the bag is removed from a dispensing rack.  
         [0069]     An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and the detailed description of a preferred embodiment. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0070]      FIG. 1  is a perspective view of a gusseted open mouth bag with bottom seal;  
         [0071]      FIG. 2  is a perspective view of the  FIG. 1  embodiment with the bag sides pulled outwardly to form bottom edges;  
         [0072]      FIG. 3  is a perspective view of the  FIG. 1  embodiment illustrating a flattened bag bottom;  
         [0073]      FIG. 4  is a perspective view of a second embodiment of bag formed from a section of gusseted tubing illustrating slitting of lower corners of the tube;  
         [0074]      FIG. 5  is a perspective view of the  FIG. 4  embodiment illustrating the outward folding of lower ends of the side gussets to form triangular portions;  
         [0075]      FIG. 6  is a perspective view of the  FIG. 4  embodiment illustrating the inward folding of the triangular portions of the  FIG. 5  embodiment;  
         [0076]      FIG. 7  is a perspective view of the  FIG. 4  embodiment illustrating a bag bottom formed from lower portions of the front and rear bag walls secured to each other and the ends of the side gussets;  
         [0077]      FIG. 8  is a perspective view of the  FIG. 4  embodiment illustrating the folding of the bag bottom along side the bag walls;  
         [0078]      FIG. 9  is a perspective view of a stack of bags of the  FIG. 4  embodiment;  
         [0079]      FIG. 10  is a front elevational view of a third embodiment illustrating a header attached at a perforation line;  
         [0080]      FIG. 11  is a front elevational view of a fourth embodiment illustrating a header having weakened areas in the hanging openings;  
         [0081]      FIG. 12  is a front elevational view of a fifth embodiment illustrating a header attached at a perforation line, having a center tab and cold stakings or hot pinnings registering the bag pack;  
         [0082]      FIG. 13  is a perspective view of the  FIG. 10  embodiment illustrating the bag pack on a dispensing rack and glue spots adhering the bags together;  
         [0083]      FIG. 14  is a perspective view of the  FIG. 4  embodiment illustrating a bag with central handles;  
         [0084]      FIG. 15  is a perspective view of the  FIG. 4  embodiment illustrating a bag with microperforations in the front and rear bag walls and the gussets;  
         [0085]      FIG. 16  is a front elevational view of a t-shirt style square bottom bag with center tab;  
         [0086]      FIG. 17  is a front elevational view of a second embodiment of a t-shirt style square bottom bag having a central glue spot;  
         [0087]      FIG. 18  is a front elevational view of a third embodiment of a t-shirt style square bottom bag having a center tab with a weakened area between the tab opening and the upper edge of the bag mouth;  
         [0088]      FIG. 19  is a front elevational view of a fourth embodiment of a t-shirt style square bottom bag having a removable center tab joined to the bag with a frangible area;  
         [0089]      FIG. 20  is a front elevational view of a fifth embodiment of a t-shirt style square bottom bag having a removable header joined to the upper edges of the bag handles with a perforation line;  
         [0090]      FIG. 21  is a front elevational view of a sixth embodiment of a t-shirt style square bottom bag having a header joined to the upper edges of the bag handles and having weakened areas in the bag support openings;  
         [0091]      FIG. 22  is a perspective view of an apparatus for forming the bags of the  FIG. 4  embodiment including gusseting and slitting the extruded tubing;  
         [0092]      FIG. 23  is a perspective view of the method of folding the lower ends of the bag gussets outwardly to form triangular portions;  
         [0093]      FIG. 24  is a perspective view of the method of folding the triangular portions inwardly as part of the bag bottom;  
         [0094]      FIG. 25 a  perspective view of the method of folding the front and rear bag walls over the triangular portions and fastening them to each other, the triangular portions and the side gussets to form the bag bottom;  
         [0095]      FIG. 26  is a bottom side view of the assembled bag illustrating the bottom and side seams;  
         [0096]      FIG. 27  is a perspective view of the method of forming the  FIG. 11  embodiment of a headered bag with attaching glue spots;  
         [0097]      FIG. 28  is a perspective view of a method of adding vent holes to the bag walls as in the  FIG. 15  embodiment;  
         [0098]      FIG. 29  is a perspective view of a method of adding handleholes to the bag walls as in the  FIG. 14  embodiment;  
         [0099]      FIG. 30  is a perspective view of a method of using a hot pin to the bag walls to one another as in the  FIG. 12  embodiment;  
         [0100]      FIG. 31  is a perspective view of a method of forming a gusseted t-shirt style bag as in the  FIG. 21  embodiment;  
         [0101]      FIG. 32  is a perspective view of a method of forming a headered t-shirt style bag as as in the  FIG. 20  embodiment;  
         [0102]      FIG. 33  is a perspective view of a bag stack of square bottom t-shirt style bags being adhered together with a hot pin through an upper portion of the bags; and  
         [0103]      FIG. 34  is a perspective view of a bag stack of square bottom t-shirt style bags being adhered together with a hot pin through the handles of the bags. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0104]     (1)  FIG. 9  illustrates a square bottomed plastic bag stack  10  providing the desired features that may be constructed from the following components. A plurality of stacked polyethylene film bags  15  is provided. As illustrated in  FIGS. 1-3 , each of the bags  15  includes front  20  and rear  25  polyethylene film walls. Each of the front  20  and rear  25  walls have first  30  and second  35  side edges, a top edge  40  and a bottom edge  45 . Each of the bags  15  has a pair of longitudinally oriented side gussets  50  attached to the first  30  and second  35  side edges. Each of the bags  15  has a flat, rectangular bottom  55  formed of lower portions  60  of the front  20  and rear  25  walls and lower portions  65  of the side gussets  50 . As illustrated in  FIGS. 8 and 9 , each of the bags  15  is folded inwardly at the side gussets  50  and upwardly from either the front wall  20  or the rear wall  25  at a point  70  spaced upwardly from the bottom edge  45 , to form a flattened bag  15 . The bags  15  are stacked upon one another and held in registration by attachment of the bags  15  to one another, thereby forming a registered bag stack  10 . As illustrated in  FIGS. 10-12 , each of the bags  15  is attached at the top edges  40  of at least one of the front  20  and rear  25  walls to at least one header strip  75 . When the bags  15  are pulled from the bag stack  10  and opened, they will stand erect upon the flat bottom  55 .  
         [0105]     (2) In a variant of the invention, as illustrated in  FIGS. 4-7 , a plurality of stacked polyethylene film bags  15  is provided. Each of the bags  15  includes front  20  and rear  25  polyethylene film walls. Each of the front  20  and rear  25  walls has first  30  and second  35  side edges, a top edge  40  and a bottom edge  45 . Each of the bags  15  has a pair of longitudinally oriented side gussets  50  attached to the first  30  and second  35  side edges. Each of the bags  15  has a flat, rectangular bottom  55  formed of lower portions  60  of the front  20  and rear  25  walls and lower portions  65  of the side gussets  50 . As illustrated in  FIG. 5 , lower corners  80  of the each side gusset  50  are folded outwardly and together to form downward pointing triangular panels  85 . As illustrated in  FIG. 6 , the triangular panels  85  are folded inwardly from the side gussets  50 . Lower portions  60  of the front  20  and rear  25  walls are folded inwardly and sealed together to form the bag bottom  55 . As illustrated in  FIGS. 8 and 9 , the bag bottom  55  is sealed to the side gussets  50  adjacent upper edges  90  of the triangular panels  85 . The triangular panels  85  are sealed to an upper surface  95  of the bag bottom  55 . Each of the bags  15  is folded inwardly at the side gussets  50  and upwardly from either the front wall  20  or the rear wall  25  at a point  70  spaced upwardly from the bottom edge  45 , to form a flattened bag  15 . The bags  15  are stacked upon one another and held in registration by attachment of the bags  15  to one another, thereby forming a registered bag stack  10 . When the bags  15  are pulled from the bag stack  10  and opened, they will stand erect upon the flat bottom  55 .  
         [0106]     (3) In a further variant, as illustrated in  FIGS. 4-7 , a plurality of stacked polyethylene film bags  15  is provided. Each of the bags  15  includes front  20  and rear  25  polyethylene film walls. Each of the front  20  and rear  25  walls has first  30  and second  35  side edges, a top edge  40  and a bottom edge  45 . Each of the bags  15  has a pair of longitudinally oriented side gussets  50  attached to the first  30  and second  35  side edges. Each of the bags  15  has a crease line  100 . The crease line  100  is parallel to the bottom edges  45  and spaced upwardly from the bottom edges  45  by approximately one half of a width  105  of one of the side gussets  50 . Each of the bags  15  is slit from the bottom edges  45  of the walls  20 ,  25  to the crease line  100  at each intersection of the front  20  and rear  25  walls and the side gussets  50 .  
         [0107]     Each of the bags  15  has a flat, rectangular bottom  55  formed of portions of the front  20  and rear  25  walls and portions of the side gussets  50 . Lower corners  80  of the each side gusset  50  are folded outwardly to the crease line  100  and together to form downward pointing triangular panels  85 . The triangular panels  85  are folded inwardly from the side gussets  50  at the crease line  100 . Lower portions  60  of the front  20  and rear  25  walls are folded inwardly from the crease line  100  and sealed together to form the bag bottom  55 . The bag bottom  55  is sealed to the side gussets  50  adjacent the crease line  100  and upper edges  90  of the triangular panels  85 . The triangular panels  85  are sealed to an upper surface  95  of the bag bottom  55 . Each of the bags  15  is folded inwardly at the side gussets  50  and upwardly from either of the front wall  20  and the rear wall  25  at the crease line  100 , to form a flattened bag  15 . The bags  15  are stacked upon one another and held in registration by attachment of the bags  15  to one another, thereby forming a registered bag stack  10 . When the bags  15  are pulled from the bag stack  10  and opened, they will stand erect upon the flat bottom  55 .  
         [0108]     (4) In still a further variant, as illustrated in  FIGS. 10-12 , each of the bags  15  is attached at the top edges  40  of at least one of the front  20  and rear  25  walls to at least one header strip  75 .  
         [0109]     (5)  
         [0110]     (6) In yet a further variant of the invention, as illustrated in  FIGS. 10 and 12 , the header strip  75  is attached at the top edges  40  of at least one of the front  20  and rear  25  walls by at least one perforation  115 .  
         [0111]     (7)  
         [0112]     (8) In still another variant, as illustrated in  FIGS. 10-13 , the header strip  75  has at least one hole  120  for suspending the bags  15  from a dispensing rack  125 .  
         [0113]     (9)  
         [0114]     (10) In yet another variant, as illustrated in  FIG. 11 , the header strip  75  includes at least one weakened area  130 . The weakened area  130  extends from the hole  120  to an upper edge  135  of the header strip  75 .  
         [0115]     (11) In a further variant of the invention, as illustrated in  FIG. 13 , the square bottomed plastic bag stack  10  includes means  140  for attaching an upper portion  145  of the rear wall  25  of a leading one of the bags  15  to an upper portion  145  of the front wall  20  of a subsequent bag  15  in the bag stack  10 . When the leading bag  15  is pulled from the bag stack  10 , the subsequent bag  15  will cause the leading bag  15  to open.  
         [0116]     (12) In still a further variant, as illustrated in  FIG. 27 , the means  140  for attaching an upper portion  145  of the rear wall  25  of a leading one of the bags  15  to an upper portion  145  of the front wall  20  of a subsequent bag  15  in the bag stack  10  is selected from the group that includes glue spotting  150 , corona treatment  155 , pressure  160  and corona treatment with pressure.  
         [0117]     (13)  
         [0118]     (14) In another variant, as illustrated in  FIG. 12 , the header strips  75  are attached to one another with at least one hot pin  165  extending through the headers  75  to maintain the bags  15  in registration.  
         [0119]     (15)  
         [0120]     (16) In still another variant of the invention, as illustrated in  FIG. 12 , the header strips  75  are attached to one another with at least one cold stake  170  extending through the headers  75  to maintain the bags  15  in registration.  
         [0121]     (17)  
         [0122]     (18) In yet another variant, as illustrated in  FIG. 14 , at least one handle opening  175  is provided. The handle opening  175  extends through the front  20  and rear  25  walls in an upper portion  145  of each of the bags  15 .  
         [0123]     (19) In a further variant, the bags  15  are formed of a porous material (not shown).  
         [0124]     (20) In still a further variant, as illustrated in  FIG. 15 , the bags  15  are formed of material having microperforations  185  penetrating at least a portion  190  of any of the bag walls  20 ,  25  and side gussets  50 .  
         [0125]     (21) In another variant, as illustrated in  FIG. 15 , the bags  15  have a plurality of ventilating openings  195  penetrating at least a portion  190  of any of the bag walls  20 ,  25  and side gussets  50 .  
         [0126]     (22) In still another variant, as illustrated in  FIG. 16 , an upper seal  200  is provided.  
         [0127]     The upper seal  200  joins the front wall  20  to the rear wall  25  at the top edges  40  of the bag walls  20 ,  25  and joins top edges  205  of the side gussets  50 . A U-shaped cutout  210  is provided. The cutout  205  commences at a first point  215  on the upper seal  200 . The first point  215  is spaced from the first side edge  30  and extends downwardly toward the bottom edges  45 , across an upper portion  145  of the bag walls  20 ,  25  and upwardly to a second point  220  on the upper seal  200 . The second point  220  is spaced from the second side edge  35 , thereby forming an open bag mouth  225  and a pair of bag handles  230  terminating at the upper seal  200 .  
         [0128]     (23) In yet another variant, as illustrated in  FIG. 16 , the bags  15  are attached to one another with at least one hot pin  165  extending through the bag handles  230  to maintain the bags  15  in registration.  
         [0129]     (24) In yet a further variant, as illustrated in  FIG. 17 , the bags  15  are attached to one another with at least one hot pin  165  extending through the upper portion  145  of the bag walls  20 ,  25  to maintain the bags  15  in registration.  
         [0130]     (25) In still a further variant, as illustrated in  FIG. 16 , the bags  15  are attached to one another with at least one cold stake  170  extending through the bag handles  230  to maintain the bags  15  in registration.  
         [0131]     (26) In another variant of the invention, as illustrated in  FIG. 17 , the bags  15  are attached to one another with at least one cold stake  170  extending through the upper portion  145  of the bag walls  20 ,  25  to maintain the bags  15  in registration.  
         [0132]     (27) In yet another variant, as illustrated in  FIG. 17 , the bags  15  further comprise a pair of apertures  235 , each of the apertures  235  penetrating the bag handles  230  at a point  440  spaced downwardly from the upper seal  200 , the apertures  235  permitting the bag stack  10  to be suspended from a dispensing rack  125 .  
         [0133]     (28) In still another variant, as illustrated in  FIG. 19 , a central tab  240  is provided. The central tab  240  extends upwardly from at least one of the front wall  20  and the rear wall  25  at the open mouth  225 . The central tab  240  has an opening  245  through it for suspending the bag stack  10 .  
         [0134]     (29) In a further variant, as illustrated in  FIG. 19 , the central tab  240  is attached to at least one of the front wall  20  and the rear wall  25  at the open mouth  225  at a weakened area  250 . The weakened area  250  permits the central tab  240  to be torn from the open mouth  225  of the bag  15  as the bag  15  is removed from a dispensing rack  125 .  
         [0135]     (30) In still a further variant, as illustrated in  FIG. 18 , the central tab  240  includes a weakened area  250 . The weakened area  250  extends from the opening  245  to an upper edge  255  of the central tab  240 . The weakened area  250  parts under pressure as the bag  15  is removed from a dispensing rack  125 .  
         [0136]     (31) In yet a further variant of the invention, as illustrated in  FIGS. 20 and 21 , at least one header strip  75  is provided. The header strip  75  is attached above the upper seal  200 .  
         [0137]     (32) In still another variant, as illustrated in  FIG. 20 , the header strip  75  is attached above the upper seal  200  with at least one perforation  115 .  
         [0138]     (33) In still a further variant, as illustrated in  FIGS. 20 and 21 , the header strip  75  has at least one hole  120  therethrough for suspending the bag stack  10 .  
         [0139]     (34) In a further variant, as illustrated in  FIG. 21 , the header strip  75  includes a weakened area  130 . The weakened area  130  extending from the hole  120  to an upper edge  135  of the header strip  75 . The weakened area  130  parting as the bag  115  is removed from a dispensing rack  125 .  
         [0140]     (35) In another variant, as illustrated in  FIGS. 22-26 , a method of making a square bottomed plastic bag stack  10 , includes the following steps. Extruding a tube of polyethylene material  260 . Forming side gussets  50  in the tube  260  and flattening the tube  260 . Cutting the flattened tube  260  perpendicular to the side gussets  50  to a first predetermined length  265 , thereby forming a bag blank  270 . The bag blank  270  has front  20  and rear  25  walls, front and rear top edges  40 , front and rear bottom edges  45 , first  30  and second  35  side edges. Slitting the bag blank  270  at intersections  320  of the side gussets  50  and the front  20  and rear  25  walls from the front  45  and rear  45  bottom edges upwardly for a first predetermined distance  325 . Folding lower corners  80  of the each side gusset  50  outwardly and together to form downward pointing triangular panels  85 . Folding the triangular panels  85  inwardly from the side gussets  50 . Folding lower portions  60  of the front  20  and rear  25  walls inwardly, as illustrated in  FIG. 8 . Sealing the front  20  and rear  25  wall together adjacent the front and rear bottom edges  45  to form a bag bottom  55 . Sealing the bag bottom  55  to the side gussets  50  adjacent upper edges  90  of the triangular panels  85 . Sealing the triangular panels  85  to an upper surface  95  of the bag bottom  55 . Folding each of the bags  15  inwardly at the side gussets  50  and upwardly from either of the front wall  20  and the rear wall  25  at a point  70  spaced upwardly from the bottom edge,  45  to form a flattened bag  15 . Stacking a plurality of the bags  15  in registration to form a bag stack  10  as illustrated in  FIG. 9 .  
         [0141]     (36) In yet another variant of the method of making a square bottomed plastic bag stack  10 , includes the following steps, as illustrated in  FIGS. 22 and 26 . Extruding a tube of polyethylene material  260 . Forming side gussets  50  in the tube  260  and flattening the tube  260 . Cutting the flattened tube  260  perpendicular to the side gussets  50  to a first predetermined length  265 , thereby forming a bag blank  270 . The bag blank  270  has front  20  and rear  25  walls, front and rear top edges  40 , front and rear bottom edges  45 , first  30  and second  35  side edges. Forming a crease line  100  in each of the bag blanks  270 . The crease line  100  is parallel to the bottom edges  45  and spaced upwardly from the bottom edges  45  by approximately one half of a width  105  of one of the side gussets  50 . Slitting each of the bag blanks  270  from the bottom edges  45  of the walls  20 ,  25  to the crease line  100  at each intersection  320  of the front  20  and rear  25  walls and the side gussets  50 . Folding lower corners of the each side gusset  50  outwardly to the crease line  100  and together to form downward pointing triangular panels  85 . Folding the triangular panels  85  inwardly from the side gussets  50  at the crease line  100 . Folding lower portions  60  of the front  20  and rear  25  walls inwardly from the crease line  100 . Sealing the front  20  and rear  25  wall together adjacent the front and rear bottom edges  45  to form a bag bottom  55 . Sealing the bag bottom  55  to the side gussets  50  adjacent the crease line  100  and upper edges  90  of the triangular panels  85 . Sealing the triangular panels  85  to an upper surface  95  of the bag bottom  55 . Folding each of the bag blanks  270  inwardly at the side gussets  50  and upwardly from either of the front wall  20  and the rear wall  25  at the crease line  100 , to form a flattened bag  15 , as illustrated in  FIG. 8 . Stacking a plurality of the bags  15  in registration to form a bag stack  10 , as illustrated in  FIG. 9 .  
         [0142]     (37) A further variant of the method of making a square bottomed plastic bag stack  10  includes the following steps, as illustrated in  FIG. 27 . Prior to stacking the bag blanks  270 , perforating the bag blank  270  at a perforation line  365 , the perforation line  365  located at a second predetermined distance  370  from the front and rear top edges  40 . Cutting the bag stack  10  above the perforation line  365  to form a plurality of bag stack header strips  75 . Attaching the header strips  75  to one another to maintain the bags  15  in registration, as illustrated in  FIGS. 30 . When the bags  15  are pulled from the bag stack  10  and opened, they will stand erect upon the flat bottom  55 .  
         [0143]     (38) A still further variant of the method of making a square bottomed plastic bag stack  10  includes the following step of cutting at least one hole  120  in the header strips  110  for suspending the bags  15  from a dispensing rack  125 , as illustrated in  FIG. 27 .  
         [0144]     (39) Yet a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of forming at least one weakened area  130 . The weakened area  130  extends from the hole  120  to an upper edge  135  of the header strip  75 , as illustrated in  FIG. 27 .  
         [0145]     (40) Still a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of attaching an upper portion  145  of the rear wall  25  of a leading one of the bags  15  to an upper portion  145  of the front wall  20  of a subsequent bag  15  in the bag stack  10 . When the leading bag  15  is pulled from the bag stack  10 , the subsequent bag  15  will cause the leading bag  15  to open, as illustrated in  FIG. 27 .  
         [0146]     (41) Another variant of the method of making a square bottomed plastic bag stack  10  includes the step of providing a means for attaching an upper portion  145  of the rear wall  25  of a leading one of the bags  15  to an upper portion  145  of the front wall  20  of a subsequent bag  15  in the bag stack  10 . The means are selected from the following group that includes glue spotting  140 , corona treatment  155 , pressure  160  and corona treatment with pressure, as illustrated in  FIG. 27 .  
         [0147]     (42) Still another variant of the method of making a square bottomed plastic bag stack  10  includes the step of driving at least one hot pin  165  through the headers  110  to maintain the bags  15  in registration, as illustrated in  FIG. 30 .  
         [0148]     (43) Yet another variant of the method of making a square bottomed plastic bag stack  10  includes the step of driving at least one cold stake  170  through the headers  110  to maintain the bags  15  in registration, as illustrated in  FIGS. 12 and 17 .  
         [0149]     (44) A further variant of the method of making a square bottomed plastic bag stack  10  includes the step of cutting at least one handle opening  175  in the bag blank  270 . The handle opening  175  extends through the front  20  and rear  25  walls in an upper portion  145  of each of the bags  15 , as illustrated in  FIG. 29 .  
         [0150]     (45) Still a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of forming the bags  15  of a porous material (not shown).  
         [0151]     (46) Yet a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of forming microperforations  185  penetrating at least a portion of any of the bag walls  20 ,  25  and side gussets  50 , as illustrated in  FIG. 15 .  
         [0152]     (47) Still a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of forming a plurality of ventilating openings  195  penetrating at least a portion of any of the bag walls  20 ,  25  and side gussets  50 , as illustrated in  FIG. 15 .  
         [0153]     (48) Another variant of the method of making a square bottomed plastic bag stack  10  includes the following steps. Prior to stacking the bag blanks  270 , joining the front wall  20  to the rear wall  25  at the top edges  40  of the bag walls  20 ,  25  and joining top edges  40  of the side gussets  50 , thereby forming an upper seal  200 . Forming a U-shaped cutout  210 . The cutout  210  commences at a first point  215  on the upper seal  200  spaced from the first side edge  30  and extends downwardly toward the bottom edges  45 , across an upper portion  145  of the bag walls  20 ,  25  and upward to a second point  220  on the upper seal  200  spaced from the second side edge  35 , thereby forming an open bag mouth  225  and a pair of bag handles  230  terminating at the upper seal  200 , as illustrated in  FIG. 31 .  
         [0154]     (49) Still another variant of the method of making a square bottomed plastic bag stack  10  includes the step of driving at least one hot pin  165  through the upper portion  145  of the bag walls  20 ,  25  to maintain the bags  15  in registration, as illustrated in  FIG. 33 .  
         [0155]     (50) A further variant of the method of making a square bottomed plastic bag stack  10  includes the step of driving at least one hot pin  165  through the bag handles  230  to maintain the bags  15  in registration, as illustrated in  FIG. 34 .  
         [0156]     (51) Yet a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of driving at least one cold stake (not shown) through the upper portion of the bag walls  20 ,  25  to maintain the bags  15  in registration.  
         [0157]     (52) Still a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of driving at least one cold stake (not shown) through the bag handles  230  to maintain the bags  15  in registration.  
         [0158]     (53) Another variant of the method of making a square bottomed plastic bag stack  10  includes the step of cutting a pair of apertures  235 , as illustrated in  FIG. 31 . Each of the apertures  235  penetrates the bag handles  230  at a point  440  spaced downwardly from the upper seal  200 . The apertures permit the bag stack  10  to be suspended from a dispensing rack  125 .  
         [0159]     (54) Still another variant of the method of making a square bottomed plastic bag stack  10  includes the step of forming a central tab  240 , as illustrated in  FIG. 31 . The central tab  240  extends upwardly from at least one of the front wall  20  and the rear wall  25  at the open mouth  225 . The central tab  240  has an opening  245  through it for suspending the bag stack  10 .  
         [0160]     (55) Yet another variant of the method of making a square bottomed plastic bag stack  10  includes the step of forming a weakened area  250 , as illustrated in  FIG. 31 . The weakened area  250  attaches the central tab  240  to at least one of the front wall  20  and the rear wall  25  at the open mouth  225 . The weakened area  250  permits the central tab  240  to be torn from the open mouth  225  of the bag  15  as the bag  15  is removed from a dispensing rack  125 .  
         [0161]     (56) A further variant of the method of making a square bottomed plastic bag stack  10  includes the step of forming the central tab  240  with a weakened area  250 , as illustrated in  FIG. 18 . The weakened area  250  extends from the opening  245  to an upper edge  255  of the central tab  240 . The weakened area  250  parts under pressure as the bag  15  is removed from a dispensing rack  125 .  
         [0162]     (57) Still a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of attaching a header strip  75  above the upper seal  200 , as illustrated in  FIG. 32 .  
         [0163]     (58) Yet a further variant of the method of making a square bottomed plastic bag stack  10  includes the step of attaching the header strip  75  above the upper seal  200  with at least one perforation  115 , as illustrated in  FIG. 32 .  
         [0164]     (59) Another variant of the method of making a square bottomed plastic bag stack  10  includes the step of cutting at least one hole  120  through the header strip  75  for suspending the bag stack  10 , as illustrated in  FIG. 32 .  
         [0165]     (60) A final variant of the method of making a square bottomed plastic bag stack  10  includes the step of forming a weakened area  130 , as illustrated in  FIG. 11 . The weakened area  130  extends from the opening  410  to an upper edge  135  of the header strip  110 . The weakened area  130  parts as the bag  15  is removed from a dispensing rack  125 .  
         [0166]     An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and the detailed description of a preferred embodiment.