Abstract:
Improved merchandise bag with reinforced bag wall is formed of thinner than normal specially selected film material with a thickened center section. For merchandise bags, the thickened center section provides a stronger bag bottom and stronger areas for the formation of bag handles. Handle bags include soft loop, round die cut oval die cut, wave top, patch and rigid handles. For T-shirt style bags, thinner plastic in the gusset and handle areas is made up for by multiple layers of film in these regions. T-shirt bags may have single, triple or folded gussets providing as many as eight layers of film in these regions. The thickened center section will substantially match the thickness of the gusseted areas and provide for a more easily stacked bag. The bags are formed of mono layer or multi-layer film and at least a portion of the bag walls is corona treated to improve adhesion.

Description:
RELATED APPLICATION 
     This application is a Continuation-in-Part of U.S. application Ser. No. 12/845,667, filed Jul. 28, 2010 and currently pending. 
     FIELD OF INVENTION 
     This invention relates to the field of merchandise bags formed from thermoplastic and plastic substitute materials and more specifically to bags designed to provide optimal strength and carrying capacity while using a reduced amounts of such materials. 
     BACKGROUND OF THE INVENTION 
     Film merchandise bags are manufactured from petroleum products and various organic material substitutes, all of which are increasingly expensive resources. It is difficult to produce such bags in formulations that are easily biodegradable. As the quantity of merchandise used daily is enormous, the production and disposal of these bags has a significant effect on the environment. For these reasons, it is desirable to produce merchandise bags that use a minimum of thermoplastic or plastic-substitute material. Some of the materials presently in use or contemplated for merchandise bags include high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, polylactic acid (PLA), poly-3-hydroxybutyrate (PHB), bio-derived polyethylene including materials produced from corn, sugar cane, tapioca, and potatoes and genetically modified bioplastics. 
     One way to minimize the use of these materials is to use a thinner gauge film in the manufacture of the bags. As merchandise bags used in the grocery and supermarket environments are often used to carry heavy loads of canned goods and other items that may have sharp edges, these merchandise bags need to have a certain minimum resistance to piercing and tearing under such conditions. Use of thinner film in bag construction can result in torn or burst bags, a situation that is not acceptable to retail stores and their customers. 
     The typical merchandise bag used in the grocery and supermarket setting is the T-Shirt style bag. This bag has a U-shaped open mouth at the upper end with a pair of strap handles extending upwardly from the mouth. In order to make the handles stronger, side gussets are typically formed prior to sealing the upper and lower edges of the bag and forming the bag mouth. This provides four layers of film material in the bag handles compared with two layers for the front and back walls of the bag. High stress areas in merchandise bags include the bag handles and the bottom of the bag, both points at which maximum tensile stress is experienced. In the present invention, several techniques may be employed to increase strength in these critical areas when using a thinner gauge film material in bag construction. These techniques include thickening one or more of the bag walls in specified locations and multiplying the layers of film material in the bag handles. Various inventions have been developed to increase strength of plastic bags. 
     U.S. Pat. No. 5,338,118, issued to DeMatteis is directed to a plastic bag having an aperture serving as a handle which has a contour of peaks and valleys. The peaks fold in an accordion-like manner when pressed by fingers to cushion the fingers. The area surrounding the bag handle opening is formed with a thicker plastic extrusion while the balance of the bag is of a standard thickness, lending strength to the handle area of the bag. 
     U.S. Pat. No. 7,223,016, issued to Bell illustrates a collapsed bag of unitary construction made of supple polymeric material, having first and second opposed contiguous flat sidewalls joined at edges and at the bottom but free or with user-releasable weakening at upper edges. The upper edges define a bag mouth. Appropriately situated graspable points at or near bag edges allow the sidewalls to be tensioned or snapped in opposing directions thereby causing the interlayer cling, to which supple polymeric bags are renownedly susceptible, to be readily disrupted for the full distance of contact between the tensioning points and thus for virtually the entirety of the bag mouth to be opened. Performance of this bag opening feature can be improved in a square-topped bag by thickening the plastic material in the area of the bag mouth. 
     U.S. Pat. No. 6,565,794, issued to Fraser discloses a tie bag having improved tie features provided by increasing the thickness of the tie features as compared to the bag thickness. 
     It is an objective of the present invention to provide a film merchandise bag having size and strength characteristics of a standard bag that can be manufactured using substantially less film material. It is another objective to provide such a bag manufactured from a thinner gauge film. It is a further objective of the invention to provide a bag that will have a more uniform thickness across the bag width, to aid in storage and packing of bag stacks. It is still a further objective to provide a bag that is resistant to failure along the bottom seam. It is yet a further objective to provide bag designs that are adaptable to use with or without dispensing racks. Finally, it is an objective of the present invention to provide durable bags that are more easily biodegraded and are economical to produce. 
     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 
     The present invention addresses all of the deficiencies of prior art merchandise bag with reinforced bag wall inventions and satisfies all of the objectives described above. 
     (1) An improved merchandise bag providing the desired features may be constructed from the following components. A typical merchandise bag includes front and rear walls of thermoplastic or other film material of uniform thickness. Each of the front and rear walls has first and second side edges, a top edge and a bottom edge. The front and rear walls are joined at the first and second side edges. A first lower seam is provided. The first lower seam seals the bottom edge of the front wall, and the bottom edge of the rear wall together. The improvement provides that at least one of the front and rear walls has an area of increased thickness and specially selected film material. The area of increased thickness extends from the top edge to the bottom edge and from a first point spaced inwardly from the first side edge by at least a first predetermined distance to a second point spaced inwardly from the second side edge by at least the first predetermined distance. The film material including about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene having a melt index ranging from 0.10-0.30 gm/10 minutes and 0-8 wt. % color concentrate. 
     (2) In a variant of the invention, the improved merchandise bag further includes 0.5 wt. % slip and antiblock compound. 
     (3) In another variant, the improved merchandise bag further includes 1-3 wt. % calcium carbonate. 
     (4) In still another variant, the improved merchandise bag further includes 10-20 wt. % recycled material. The recycled material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate. 
     (5) In yet another variant, 10-15 wt. % of the linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc. 
     (6) In a further variant, 10-15 wt. % of the linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes. 
     (7) In still a further variant, the high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc. 
     (8) In yet a further variant, the film material includes at least one of polylactic acid (PLA), poly-3-hydroxybutyrate (PHB), bio-derived polyethylene including materials produced from corn, sugar cane, tapioca, and potatoes and genetically modified bioplastics. 
     (9) In another variant of the invention, the improved merchandise bag includes a second lower seam. The second lower seam is spaced upwardly from the first lower seam by a second predetermined distance. 
     (10) In still another variant, the improved merchandise bag includes a centrally located handle. 
     (11) In yet another variant, the handle is selected from the group consisting of soft loop, round die cut, oval die cut, wave top, patch and rigid. 
     (12) In a further variant, the bag is formed of mono layer or multi-layer film material. 
     (13) In still a further variant, at least a portion of at least one of the front and rear bag walls is corona treated. 
     (14) In yet a further variant, the area of increased thickness ranges from 125% to 130% of the thickness of a balance of film material in the bag. 
     (15) In another variant of the invention, the balance of film material in the bag is 80% to 85% of the thickness of thermoplastic material of the typical merchandise bag. 
     (16) In still another variant, the bag includes 90% to 92% of the film material of the typical merchandise bag. 
     (17) In yet another variant the area of increased thickness is 8% to 15% thicker than the film material of the typical merchandise bag. 
     (18) In a further variant of the invention, an improved gusseted merchandise bag is described. A typical gusseted merchandise bag includes front and rear walls of film material of uniform thickness. Each of the front and rear walls has first and second side edges, a top edge and a bottom edge. First and second side gussets are provided. The side gussets have upper and lower edges and extend inwardly from the first and second side edges of the front and rear walls for a first predetermined distance. A first lower seam is provided. The first lower seam seals the bottom edge of the front wall, lower edges of the first and second side gussets and the bottom edge of the rear wall together. The improvement provides that at least one of the front and rear walls has an area of increased thickness and specially selected film material. The area of increased thickness extends from the top edge to the bottom edge and from a first point spaced inwardly from the first side edge by at least the first predetermined distance to a second point spaced inwardly from the second side edge by at least the first predetermined distance. The film material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene having a melt index ranging from 0.10-0.30 gm/10 minutes and 0-8 wt. % color concentrate. 
     (19) In still a further variant of the invention, the improved merchandise bag further includes 0.5 wt. % slip and antiblock compound. 
     (20) In yet a further variant, the improved merchandise bag further includes 1-3 wt. % calcium carbonate. 
     (21) In another variant, the improved merchandise bag further includes 10-20 wt. % recycled material. The recycled material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate. 
     (22) In still another variant, 10-15 wt. % of the linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc. 
     (23) In yet another variant, 10-15 wt. % of the linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes. 
     (24) In a further variant, the high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc. 
     (25) In still a further variant, the film material includes at least one of polylactic acid (PLA), poly-3-hydroxybutyrate (PHB), bio-derived polyethylene including materials produced from corn, sugar cane, tapioca, and potatoes and genetically modified bioplastics. 
     (26) In another variant, a second lower seam is provided. The second seam is spaced upwardly from the first lower seam by a second predetermined distance. 
     (27) In another variant, the improved gusseted merchandise bag includes a centrally located handle. 
     (28) In still another variant, the handle is selected from the group consisting of soft loop, round die cut, oval die cut, wave top, patch and rigid. 
     (29) In yet another variant, the improved gusseted bag is formed of mono layer or multi-layer film material. 
     (30) In a further variant, at least a portion of at least one of the front and rear bag walls is corona treated. 
     (31) In still a further variant, the area of increased thickness ranges from 125% to 130% of the thickness of a balance of film material in the bag. 
     (32) In another variant of the invention, the balance of film material in the bag is 80% to 85% of the thickness of film material of the typical gusseted merchandise bag. 
     (33) In still another variant, the bag includes 90% to 92% of the film material of the typical gusseted merchandise bag. 
     (34) In yet another variant the area of increased thickness is 8% to 15% thicker than the film material of the typical gusseted merchandise bag. 
     (35) An improved T-Shirt style bag providing the desired features may be constructed from the following components. A typical T-Shirt style bag includes front and rear walls of film material of uniform thickness. Each of the front and rear walls has first and second side edges, a top edge and a bottom edge. First and second side gussets are provided. The side gussets have upper and lower edges and extend inwardly from the first and second side edges of the front and rear walls for a first predetermined distance. 
     An upper seam is provided. The upper seam seals the top edge of the front wall, upper edges of the first and second side gussets and the top edge of the rear wall together. A first lower seam is provided. The first lower seam seals the bottom edge of the front wall, lower edges of the first and second side gussets and the bottom edge of the rear wall together. A U-shaped cut-out is provided. The U-shaped cut-out is located in an upper portion of the bag and commences at a first point along the top edge spaced inwardly from the first side edge and extending to a second point along the top edge spaced inwardly from the second side edge, the cut-out extending downwardly toward the bottom edges, thereby forming an open mouth portion and a pair of bag handles. The improvement provides that at least one of the front and rear walls has an area of increased thickness and specially selected film material. The area of increased thickness extends from the open mouth portion to the bottom edge and from a first point spaced inwardly from the first side edge by at least the first predetermined distance to a second point spaced inwardly from the second side edge by at least the first predetermined distance. The film material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene having a melt index ranging from 0.10-0.30 gm/10 minutes and 0-8 wt. % color concentrate. 
     (36) In a variant of the invention, the improved T-Shirt style bag further includes 0.5 wt. % slip and antiblock compound. 
     (37) In another variant, the improved T-Shirt style bag further includes 1-3 wt. % calcium carbonate. 
     (38) In still another variant, the improved T-Shirt style bag further includes 10-20 wt. % recycled material. The recycled material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate. 
     (39) In yet another variant, 10-15 wt. % of the linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc. 
     (40) In a further variant, 10-15 wt. % of the linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes. 
     (41) In still a further variant, the high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc. 
     (42) In yet a further variant, the film material includes at least one of polylactic acid (PLA), poly-3-hydroxybutyrate (PHB), bio-derived polyethylene including materials produced from corn, sugar cane, tapioca, and potatoes and genetically modified bioplastics. 
     (43) In another variant of the invention, a third side gusset is provided. The third side gusset has an upper edge and a lower edge and extends inwardly from the first side edge of the front wall for a second predetermined distance and outwardly for a third predetermined distance to join the first side gusset. A fourth side gusset is provided. The fourth side gusset has an upper edge and a lower edge and extends inwardly from the first side edge of the rear wall for the second predetermined distance and outwardly for the third predetermined distance to join the first side gusset. A fifth side gusset is provided. The fifth side gusset has an upper edge and a lower edge and extends inwardly from the second side edge of the front wall for the second predetermined distance and outwardly for the third predetermined distance to join the second side gusset. A sixth side gusset is provided. The sixth side gusset has an upper edge and a lower edge and extends inwardly from the second side edge of the rear wall for the second predetermined distance and outwardly for the third predetermined distance to join the second side gusset. The upper seam seals the top edge of the front wall, upper edges of the first, second, third, fourth, fifth and sixth side gussets and the top edge of the rear wall together. The first lower seam seals the bottom edge of the front wall, lower edges of the first, second, third, fourth, fifth and sixth side gussets and the bottom edge of the rear wall together. 
     (44) In still another variant, a first folded portion is provided. The first folded portion has an upper edge and a lower edge and is folded into the first side gusset from the first side edge of the front wall for a second predetermined distance. A second folded portion is provided. The second folded portion has an upper edge and a lower edge and is folded into the first side gusset from the first side edge of the rear wall for the second predetermined distance. A third folded portion is provided. The third folded portion has an upper edge and a lower edge and is folded into the second side gusset from the second side edge of the front wall for the second predetermined distance. A fourth folded portion is provided. The fourth folded portion has an upper edge and a lower edge and is folded into the second side gusset from the second side edge of the rear wall for the second predetermined distance. The upper seam seals the top edge of the front wall, upper edges of the first and second side gussets, upper edges of the first, second, third and fourth folded portions and the top edge of the rear wall together. The first lower seam seals the bottom edge of the front wall, lower edges of the first and second side gussets, lower edges of the first, second, third and fourth folded portions and the bottom edge of the rear wall together. 
     (45) In yet another variant, first and second openings are provided. The first and second openings penetrate and extend transversely through each of the bag handles. The openings are spaced downwardly from the top edge, spaced inwardly from the first and second side edges and serve to support the bag on horizontal arms of a dispensing rack. 
     (46) In a further variant, at least a portion of at least one of the front and rear bag walls is corona treated. 
     (47) In still a further variant, a central tab portion connected to the open mouth portion of the bag is provided. An aperture is provided. The aperture extends transversely through the bag within the central tab portion for suspending the bag from a dispensing rack. 
     (48) In yet a further variant, the central tab portion is attached to the open mouth portion with a frangible section. The frangible section breaks when the bag is pulled from a dispensing rack. 
     (49) In another variant of the invention, the aperture in the central tab portion includes a frangible portion. The frangible portion breaks when the bag is pulled from the dispensing rack. 
     (50) In still another variant, the open mouth portion includes stress relief areas. The stress relief areas have curved inner corners wherein a cut line forming the corners extends from a vertical inner edge of the bag handle outwardly toward one of the first and second side edges, downwardly toward the lower seam and upwardly at a shallow angle toward a center line of the front and rear bag walls, thereby reducing the likelihood that the open mouth portion may tear under tension. 
     (51) In a further variant, a second lower seam is provided. The second lower seam is spaced upwardly from said first lower seam by a second predetermined distance. 
     (52) In still a further variant, the area of increased thickness ranges from 125% to 130% of the thickness of a balance of film material in the bag. 
     (53) In yet a further variant of the invention, the balance of film material in the bag is 80% to 85% of the thickness of film material of the typical merchandise bag. 
     (54) In another variant, the bag includes 90% to 92% of the film material of the typical T-Shirt style bag. 
     (55) In still another variant the area of increased thickness is 8% to 15% thicker than the film material of the typical T-Shirt style bag. 
     (56) In yet another variant, the improved T-Shirt style bag further includes at least one pair of additional first side edge gussets. Each of the first side edge gussets has an upper edge and a lower edge and extends inwardly from the first side edge of either the front wall, the rear wall or one of the additional first side edge gussets for a second predetermined distance and outwardly for a third predetermined distance to join either the first side gusset or one of the additional first side edge gussets. The improved T-Shirt style bag also further includes at least one pair of additional second side edge gussets. Each of the second side edge gussets has an upper edge and a lower edge and extends inwardly from the second side edge of either the front wall, the rear wall or one of the additional second side edge gussets for the second predetermined distance and outwardly for the third predetermined distance to join either the second side gusset or one of the additional second side edge gussets. 
     The upper seam seals the top edge of the front wall, the upper edges of the first and second gussets, at least one pair of additional first side edge gussets, at least one pair of additional second side edge gussets and the top edge of the rear wall together. The lower seam seals the bottom edge of the front wall, the lower edges of the first and second gussets, at least one pair of additional first side edge gussets, at least one pair of additional second side edge gussets and the bottom edge of the rear wall together. 
     (57) In a final variant, the improved T-Shirt style bag further includes at least one pair of first side folded portions. The first side folded portions have an upper edge and a lower edge and are folded into either the first side gusset or one of the first side folded portions from the first side edge of either the front wall, the rear wall or one of the first side folded portions for a second predetermined distance. The improved T-Shirt style bag also further includes at least one pair of second side folded portions. The second side folded portions have an upper edge and a lower edge and are folded into either the second side gusset or one of the second side folded portions from the second side edge of either the front wall, the rear wall or one of the second side folded portions for the second predetermined distance. 
     The upper seam seals the top edge of the front wall, the upper edges of the first and second side gussets, the upper edges of the at least one pair of first side folded portions and the at least one pair of second side folded portions and the top edge of the rear wall together. The lower seam seals the bottom edge of the front wall, the lower edges of the first and second side gussets, the lower edges of the at least one pair of first side folded portions and the at least one pair of second side folded portions and the bottom edge of the rear wall together. 
     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 
         FIG. 1  is a perspective view of the preferred embodiment of the invention illustrating an improved merchandise bag with soft loop handle and area of increased wall thickness; 
         FIG. 1A  is a perspective view of a typical merchandise bag having walls of uniform thickness; 
         FIG. 2  is a cross-sectional view of the  FIG. 1  embodiment taken along the line  2 - 2 ; 
         FIG. 2A  is a cross-sectional view of the  FIG. 1A  embodiment taken along the line  2 A- 2 A; 
         FIG. 2B  is an enlarged view of the circled portion of  FIG. 2 ; 
         FIG. 3  is a perspective view of a second embodiment featuring a patch handle centered in the reinforced bag wall; 
         FIG. 4  is a cross-sectional view of the  FIG. 3  embodiment taken along the line  4 - 4 ; 
         FIG. 5  is a perspective view of a third embodiment featuring a wave top bag mouth and a round die cut handle centered in the reinforced bag wall; 
         FIG. 6  is a cross-sectional view of the  FIG. 5  embodiment taken along the line  6 - 6 ; 
         FIG. 7  is a perspective view of a fourth embodiment featuring a rigid handle; 
         FIG. 8  is a cross-sectional view of the  FIG. 7  embodiment taken along the line  8 - 8 ; 
         FIG. 9  is a perspective view of a fifth embodiment featuring a pair of side gussets, area of increased wall thickness and an oval die cut handle; 
         FIG. 9A  is a perspective view of a typical gusseted merchandise bag having walls of uniform thickness; 
         FIG. 10  is a cross-sectional view of the  FIG. 9  embodiment taken along the line  10 - 10 ; 
         FIG. 10A  is a cross-sectional view of the  FIG. 9A  embodiment taken along the line  10 A- 10 A; 
         FIG. 11  is a perspective view of a sixth embodiment of the invention illustrating an improved gusseted T-shirt style bag having an area of increased wall thickness; 
         FIG. 12  is a front elevation of the  FIG. 11  embodiment; 
         FIG. 13A  is a cross-sectional perspective view of the  FIG. 11  embodiment taken along the line  13 A- 13 A, illustrating a folded gusset bag; 
         FIG. 13B  is a cross-sectional perspective view of the  FIG. 11  embodiment taken along the line  13 B- 13 B, illustrating a triple gusseted bag; 
         FIG. 14  is a front elevation of the  FIG. 11  embodiment illustrating a single gusseted T-Shirt style bag; 
         FIG. 14A  is a front elevation of a typical, single gusseted T-Shirt style bag having walls of uniform thickness; 
         FIG. 15  is a cross-sectional perspective view of the  FIG. 14  embodiment taken along the line  15 - 15 , illustrating a single gusset bag; 
         FIG. 15A  is a cross-sectional perspective view of the  FIG. 14A  embodiment taken along the line  15 A- 15 A, illustrating a single gusset bag having walls of uniform thickness; 
         FIG. 16  is a partial front view of the  FIG. 14  embodiment illustrating a tabless center tab bag with frangible aperture and stress relief bag mouth design; 
         FIG. 17  is a partial front view of the  FIG. 14  embodiment illustrating a tabbed center tab bag with frangible attachment to the bag mouth and stress relief bag mouth design; 
         FIG. 18  is a table illustrating the Free-Falling Dart method test results; and 
         FIG. 19  is a table illustrating Propagation Tear Resistance of Plastic Film and Thin Sheet by Pendulum Method. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     (1)  FIGS. 1-10  illustrate an improved merchandise bag  8  providing the desired features that may be constructed from the following components. As illustrated in  FIGS. 1A and 2A , a typical merchandise bag  4  includes front  12  and rear  16  walls of film material  15  of uniform thickness  6 . Each of the front  12  and rear  16  walls has first  20  and second  24  side edges, a top edge  28  and a bottom edge  32 . The front  12  and rear  16  walls are joined at the first  20  and second  24  side edges. A first lower seam  36  is provided. The first lower seam  36  seals the bottom edge  32  of the front wall  12 , and the bottom edge  32  of the rear wall  16  together. As illustrated in  FIGS. 1 and 2 , the improvement provides that at least one of the front  12  and rear  16  walls has an area of increased thickness  40  and specially selected film material  15 . The area of increased thickness  40  extends from the top edge  28  to the bottom edge  32  and from a first point  44  spaced inwardly from the first side edge  20  by at least a first predetermined distance  48  to a second point  52  spaced inwardly from the second side edge  24  by at least the first predetermined distance  48 . The film material  15  including about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene having a melt index ranging from 0.10-0.30 gm/10 minutes and 0-8 wt. % color concentrate. 
     (2) In a variant of the invention, the improved merchandise bag  8  further includes 0.5 wt. % slip and antiblock compound. 
     (3) In another variant, the improved merchandise bag  8  further includes 1-3 wt. % calcium carbonate. 
     (4) In still another variant, the improved merchandise bag  8  further includes 10-20 wt. % recycled material. The recycled material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate. 
     (5) In yet another variant, 10-15 wt. % of the linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc. 
     (6) In a further variant, 10-15 wt. % of the linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes. 
     (7) In still a further variant, the high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc. 
     (8) In yet a further variant, the film material includes at least one of polylactic acid (PLA), poly-3-hydroxybutyrate (PHB), bio-derived polyethylene including materials produced from corn, sugar cane, tapioca, and potatoes and genetically modified bioplastics. 
     (9) In another variant of the invention, as illustrated in  FIGS. 1 and 3 , the improved merchandise bag  8  includes a second lower seam  56 . The second lower seam  56  is spaced upwardly from the first lower seam  36  by a second predetermined distance  60 . 
     (10) In still another variant, as illustrated in  FIGS. 1-10 , the improved merchandise bag  8  includes a centrally located handle  64 . 
     (11) In yet another variant, the handle  64  is selected from the group consisting of soft loop  68 , round die cut  72 , oval die cut  76 , wave top  80 , patch  84  and rigid  88 . 
     (12) In a further variant, the bag  8  is formed of mono layer  89  or multi-layer  91  film material as shown in  FIGS. 2A and 2B , respectively. 
     (13) In still a further variant, at least a portion  92  of at least one of the front  12  and rear  16  bag walls is corona treated  96 . 
     (14) In yet a further variant, the area of increased thickness  40  ranges from 125% to 130% of the thickness of a balance of film material  97  in the bag  8 . 
     (15) In another variant of the invention, the balance of thermoplastic material  97  in the bag  8  is 80% to 85% of the thickness of film material of the typical merchandise bag  4 . 
     (16) In still another variant, the bag  8  includes 90% to 92% of the film material of the typical merchandise bag  4 . 
     (17) In yet another variant the area of increased thickness  40  is 8% to 15% thicker than the film material of the typical merchandise bag  4 . 
     (18) In a further variant of the invention, an improved gusseted merchandise bag  13 , is illustrated in  FIGS. 9 and 10 . As illustrated in  FIGS. 9A and 10A , a typical gusseted merchandise bag  9 , includes front  12  and rear  16  walls of film material  15  of uniform thickness  6 . Each of the front  12  and rear  16  walls has first  20  and second  24  side edges, a top edge  28  and a bottom edge  32 . First  100  and second  104  side gussets are provided. The side gussets  100 ,  104  have upper  108  and lower  112  edges and extend inwardly from the first  20  and second  24  side edges of the front  12  and rear  16  walls for a first predetermined distance  48 . A first lower seam  36  is provided. The first lower seam  36  seals the bottom edge  32  of the front wall  12 , lower edges  112  of the first  100  and second  104  side gussets and the bottom edge  32  of the rear wall  16  together. As illustrated in  FIGS. 9 and 10 , the improvement provides that at least one of the front  12  and rear  16  walls has an area of increased thickness  40  and specially selected film material  15 . The area of increased thickness  40  extends from the top edge  28  to the bottom edge  32  and from a first point  44  spaced inwardly from the first side edge  20  by at least the first predetermined distance  48  to a second point  52  spaced inwardly from the second side edge  24  by at least the first predetermined distance  48 . The film material  15  includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene having a melt index ranging from 0.10-0.30 gm/10 minutes and 0-8 wt. % color concentrate. 
     (19) In still a further variant of the invention, the improved merchandise bag  13  further includes 0.5 wt. % slip and antiblock compound. 
     (20) In yet a further variant, the improved merchandise bag  13  further includes 1-3 wt. % calcium carbonate. 
     (21) In another variant, the improved merchandise bag  13  further includes 10-20 wt. % recycled material. The recycled material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate. 
     (22) In still another variant, 10-15 wt. % of the linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc. 
     (23) In yet another variant, 10-15 wt. % of the linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes. 
     (24) In a further variant, the high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc. 
     (25) In still a further variant, the film material  15  includes at least one of polylactic acid (PLA), poly-3-hydroxybutyrate (PHB), bio-derived polyethylene including materials produced from corn, sugar cane, tapioca, and potatoes and genetically modified bioplastics. 
     (26) In another variant, a second lower seam  56  is provided. The second lower seam  56  is spaced upwardly from the first lower seam  36  by a second predetermined distance  60 . 
     (27) In another variant, the improved gusseted merchandise bag  13  includes a centrally located handle  64 . 
     (28) In still another variant, as illustrated in  FIGS. 1-10 , the handle  64  is selected from the group consisting of soft loop  68 , round die cut  72 , oval die cut  76 , wave top  80 , patch  84  and rigid  88 . 
     (29) In yet another variant, the improved bag  8  is formed of mono layer  89 , as illustrated in  FIGS. 3 and 4 , or multi-layer  91  film material, as illustrated in  FIGS. 2 and 2B . 
     (30) In a further variant, at least a portion  92  of at least one of the front  12  and rear  16  bag walls is corona treated  96 , as illustrated in  FIG. 1 . 
     (31) In still a further variant, as illustrated in  FIGS. 9 and 10 , the area of increased thickness  40  ranges from 125% to 130% of the thickness of a balance of film material  97  in the bag  13 . 
     (32) In another variant of the invention, the balance of film material  97  in the bag  13  is 80% to 85% of the thickness of film material of the typical gusseted merchandise bag  9 . 
     (33) In still another variant, the bag  13  includes 90% to 92% of the film material of the typical gusseted merchandise bag  9 . 
     (34) In yet another variant the area of increased thickness  40  is 8% to 15% thicker than the film material of the typical gusseted merchandise bag  9 . 
     (35)  FIGS. 11-17  illustrate an improved T-Shirt style bag  10  providing the desired features that may be constructed from the following components. As illustrated in  FIGS. 14A and 15A , a typical T-Shirt style bag  11  includes front  14  and rear  18  walls of film material  15  of uniform thickness  6 . Each of the front  14  and rear  18  walls has first  22  and second  26  side edges, a top edge  30  and a bottom edge  34 . First  38  and second  42  side gussets are provided. The side gussets  38 ,  42  have upper  46  and lower  50  edges and extend inwardly from the first  22  and second  26  side edges of the front  14  and rear  18  walls for a first predetermined distance  54 . 
     An upper seam is provided  58 . The upper seam  58  seals the top edge  30  of the front wall  14 , upper edges  46  of the first  38  and second  42  side gussets and the top edge  30  of the rear wall  18  together. A first lower seam  62  is provided. The first lower seam  62  seals the bottom edge  34  of the front wall  14 , lower edges  50  of the first  38  and second  42  side gussets and the bottom edge  34  of the rear wall  18  together. A U-shaped cut-out  66  is provided. The U-shaped cut-out  66  is located in an upper portion  70  of the bag  11  and commences at a first point  74  along the top edge  30  spaced inwardly from the first side edge  22  and extending to a second point  78  along the top edge  30  spaced inwardly from the second side edge  26 , the cut-out  66  extending downwardly toward the bottom edges  34 , thereby forming an open mouth portion  82  and a pair of bag handles  86 ,  90 . As illustrated in  FIGS. 14 and 15 , the improvement provides that at least one of the front  14  and rear  18  walls has an area of increased thickness  94  and specially selected film material  15 . The area of increased thickness  94  extends from the open mouth portion  82  to the bottom edge  34  and from a first point  98  spaced inwardly from the first side edge  22  by at least the first predetermined distance  54  to a second point  102  spaced inwardly from the second side edge  26  by at least the first predetermined distance  54 . The film material  15  includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene having a melt index ranging from 0.10-0.30 gm/10 minutes and 0-8 wt. % color concentrate. 
     (36) In a variant of the invention, the improved T-Shirt style bag  10  further includes 0.5 wt. % slip and antiblock compound. 
     (37) In another variant, the improved T-Shirt style bag  10  further includes 1-3 wt. % calcium carbonate. 
     (38) In still another variant, the improved T-Shirt style bag  10  further includes 10-20 wt. % recycled material. The recycled material includes about 40-48 wt. % high density, high molecular weight polyethylene, 12-20 wt. % high density, medium molecular weight polyethylene, 20-30 wt. % linear low density polyethylene, 0-8 wt. % color concentrate. 
     (39) In yet another variant, 10-15 wt. % of the linear low density polyethylene has a density ranging from 0.923-0.924 gm/cc. 
     (40) In a further variant, 10-15 wt. % of the linear low density polyethylene has a melt index ranging from 0.25-0.30 gm/10 minutes. 
     (41) In still a further variant, the high density, medium molecular weight polyethylene has a density ranging from 0.937-0.947 gm/cc. 
     (42) In yet a further variant, the film material  15  includes at least one of polylactic acid (PLA), poly-3-hydroxybutyrate (PHB), bio-derived polyethylene including materials produced from corn, sugar cane, tapioca, and potatoes and genetically modified bioplastics. 
     (43) In a variant of the invention, as illustrated in  FIGS. 12 and 13B , a third side gusset  106  is provided. The third side gusset  106  has an upper edge  110  and a lower edge  114  and extends inwardly from the first side edge  22  of the front wall  14  for a second predetermined distance  118  and outwardly for a third predetermined distance  122  to join the first side gusset  38 . A fourth side gusset  126  is provided. The fourth side gusset  126  has an upper edge  110  and a lower edge  114  and extends inwardly from the first side edge  22  of the rear wall  18  for the second predetermined distance  118  and outwardly for the third predetermined distance  122  to join the first side gusset  38 . A fifth side gusset  130  is provided. The fifth side gusset  130  has an upper edge  110  and a lower edge  114  and extends inwardly from the second side edge  26  of the front wall  14  for the second predetermined distance  118  and outwardly for the third predetermined distance  122  to join the second side gusset  42 . A sixth side gusset  134  is provided. The sixth side gusset  134  has an upper edge  110  and a lower edge  114  and extends inwardly from the second side edge  26  of the rear wall  18  for the second predetermined distance  118  and outwardly for the third predetermined distance  122  to join the second side gusset  42 . The upper seam  58  seals the top edge  30  of the front wall  14 , upper edges  110  of the first  38 , second  42 , third  106 , fourth  126 , fifth  130  and sixth  134  side gussets and the top edge  30  of the rear wall  18  together. The first lower seam  62  seals the bottom edge  34  of the front wall  14 , lower edges  114  of the first  38 , second  42 , third  106 , fourth  126 , fifth  130  and sixth  134  side gussets and the bottom edge  34  of the rear wall  18  together. 
     (44) In another variant, as illustrated in  FIGS. 11 and 13A , a first folded portion  138  is provided. The first folded portion  138  has an upper edge  142  and a lower edge  146  and is folded into the first side gusset  38  from the first side edge  22  of the front wall  14  for a second predetermined distance  150 . A second folded portion  154  is provided. The second folded portion  154  has an upper edge  142  and a lower edge  146  and is folded into the first side gusset  38  from the first side edge  22  of the rear wall  18  for the second predetermined distance  150 . A third folded portion  158  is provided. The third folded portion  158  has an upper edge  142  and a lower edge  146  and is folded into the second side gusset  42  from the second side edge  26  of the front wall  14  for the second predetermined distance  150 . A fourth folded portion  162  is provided. The fourth folded portion  162  has an upper edge  142  and a lower edge  146  and is folded into the second side gusset  42  from the second side edge  26  of the rear wall  18  for the second predetermined distance  150 . The upper seam  58  seals the top edge  30  of the front wall  14 , upper edges  46  of the first  38  and second  42  side gussets, upper edges  142  of the first  138 , second  154 , third  158  and fourth  162  folded portions and the top edge  30  of the rear wall  18  together. The first lower seam  62  seals the bottom edge  34  of the front wall  14 , lower edges  50  of the first  38  and second  42  side gussets, lower edges  146  of the first  138 , second  154 , third  158  and fourth  162  folded portions and the bottom edge  34  of the rear wall  18  together. 
     (45) In still another variant, as illustrated in  FIGS. 11 ,  12  and  14 , first  166  and second  170  openings are provided. The first  166  and second  170  openings penetrate and extend transversely through each of the bag handles  86 ,  90 . The openings  166 ,  170  are spaced downwardly from the top edge  30 , spaced inwardly from the first  22  and second  26  side edges and serve to support the bag  10  on horizontal arms (not shown) of a dispensing rack (not shown). 
     (46) In yet another variant, at least a portion  174  of at least one of the front  14  and rear  18  bag walls is corona treated. 
     (47) In a further variant, as illustrated in  FIGS. 16 and 17 , a central tab portion  178  connected to the open mouth portion  82  of the bag  10  is provided. An aperture  182  is provided. The aperture  182  extends transversely through the bag  10  within the central tab portion  178  for suspending the bag  10  from a dispensing rack. 
     (48) In still a further variant, as illustrated in  FIG. 17 , the central tab portion  178  is attached to the open mouth portion  82  with a frangible section  186 . The frangible section  186  breaks when the bag  10  is pulled from the dispensing rack. 
     (49) In another variant of the invention, as illustrated in  FIG. 16 , the aperture  182  in the central tab portion  178  includes a frangible portion  190 . The frangible portion  190  breaks when the bag  10  is pulled from the dispensing rack. 
     (50) In still another variant, as illustrated in  FIG. 14 , the open mouth portion  82  includes stress relief areas  194 . The stress relief areas  194  have curved inner corners  198  wherein a cut line  202  forming the corners  198  extends from a vertical inner edge  206  of the bag handle  86 ,  90  outwardly toward one of the first  22  and second  26  side edges, downwardly toward the lower seam  62  and upwardly at a shallow angle toward a center line  210  of the front  14  and rear  18  bag walls, thereby reducing the likelihood that the open mouth portion  82  may tear under tension. 
     (51) In a further variant, a second lower seam  214  is provided. The second lower seam  214  is spaced upwardly from said first lower seam  62  by a second predetermined distance  218 . 
     (52) In yet a further variant, the area of increased thickness  94  ranges from 125% to 130% of the thickness of a balance of film material  95  in the bag  10 . 
     (53) In another variant of the invention, the balance of film material  95  in the improved bag  10  is 80% to 85% of the thickness of thermoplastic material of the typical T-Shirt style bag  11 . 
     (54) In still another variant, the bag  10  includes 90% to 92% of the film material of the typical T-Shirt style bag  11 . 
     (55) In yet another variant the area of increased thickness  94  is 8% to 15% thicker than the film material of the typical T-Shirt style bag  11 . 
     Conventional gusseted bags as illustrated in  FIGS. 9A ,  10 A,  14 A and  15 A have two point of inherent weakness  116 ,  120  on the lower seam  36 ,  62  at the points where the gusseted portions  100 ,  104  and  38 ,  42  meet the ungusseted portions of the bag walls  12 ,  16  and  14 ,  18 . The reason for this is that conventional gusseted bags  9  and  11  are made of film of uniform thickness. In a bag  9  and  11  having a single gusset  100 ,  104  and  38 ,  42  at each side, when the bags  9  and  11  are being formed and the gussets  100 ,  104  and  38 ,  42  are folded in place, there will be four layers of plastic in the gusseted portions  100 ,  104  and  38 ,  42  of the bag  9  and  11  while there will be only two layers in the center, ungusseted portion of the bag  9  and  11 . When the lower edge  32  and  50  of the bag is heat sealed, there will be twice as much plastic to heat seal together at the gusseted portions  100 ,  104  and  38 ,  42  as at the ungusseted portion. This leads to compromises as to the temperature and pressure to apply to the lower seam of the bag  9  and  11  so as to join all four layers in the gusseted portions  100 ,  104  and  38 ,  42  while not overheating and damaging the ungusseted portion. 
     In the present invention, as illustrated in  FIGS. 9 ,  10 ,  14  and  15  in which the gusseted portions  100 ,  104  and  38 ,  42  of the bag  10  and  13  can be approximately half of the film thickness as the ungusseted portions, a single side gusset bag  10  and  13  will have substantially the same thickness for the four layers in the gusseted portions  100 ,  104  and  38 ,  42  of the bag  10  and  13  as for the two layers in the ungusseted portion. As a result, heat and pressure used in forming the lower seam of the bag  10  and  13  can be optimized for the strongest possible bag bottom. The present invention also provides for bag designs that include folded-in gussets and multiple gussets, as illustrated in  FIGS. 12 ,  13 A and  13 B. The reduction in thickness of the plastic film used in the gusseted portions of the bags  10  is particularly important for these designs as they would otherwise have much more significant differences in thickness of the plastic layers to be sealed together to form a bag bottom. 
     (56) In a further variant, as illustrated in  FIGS. 12 and 13B , the improved T-Shirt style bag  10  further includes at least one pair of additional first side edge gussets  106 ,  126 . Each of the first side edge gussets  106 ,  126  has an upper edge  110  and a lower edge  114  and extends inwardly from the first side edge  22  of either the front wall  14 , the rear wall  18  or one of the additional first side edge gussets  106 ,  126  for a second predetermined distance  118  and outwardly for a third predetermined distance  122  to join either the first side gusset  38  or one of the additional first side edge gussets  106 ,  126 . The improved T-Shirt style bag  10  also further includes at least one pair of additional second side edge gussets  130 ,  134 . Each of the second side edge gussets  130 ,  134  has an upper edge  110  and a lower edge  114  and extends inwardly from the second side edge  26  of either the front wall  14 , the rear wall  18  or one of the additional second side edge gussets  130 ,  134  for the second predetermined distance  118  and outwardly for the third predetermined distance  122  to join either the second side gusset  42  or one of the additional second side edge gussets  130 ,  134 . 
     The upper seam  58  seals the top edge  30  of the front wall  14 , the upper edges  110  of the first  38  and second  42  gussets, at least one pair of additional first side edge gussets  106 ,  126 , at least one pair of additional second side edge gussets  130 ,  134  and the top edge  30  of the rear wall  18  together. The lower seam  62  seals the bottom edge  34  of the front wall  14 , the lower edges  114  of the first  38  and second  42  gussets, at least one pair of additional first side edge gussets  106 ,  126 , at least one pair of additional second side edge gussets  130 ,  134  and the bottom edge  34  of the rear wall  18  together. 
     (5) In a final variant, as illustrated in  FIGS. 11 and 13A , the improved T-Shirt style bag  10  further includes at least one pair of first side folded portions  138 ,  154 . The first side folded portions  138 ,  154  have an upper edge  142  and a lower edge  146  and are folded into either the first side gusset  38  or one of the first side folded portions  138 ,  154  from the first side edge  22  of either the front wall  14 , the rear wall  18  or one of the first side folded portions  138 ,  154  for a second predetermined distance  150 . The improved T-Shirt style bag  10  also further includes at least one pair of second side folded portions  158 ,  162 . The second side folded portions  158 ,  162  have an upper edge  142  and a lower edge  146  and are folded into either the second side gusset  42  or one of the second side folded portions  158 ,  162  from the second side edge  26  of either the front wall  14 , the rear wall  18  or one of the second side folded portions  158 ,  162  for the second predetermined distance  150 . 
     The upper seam  58  seals the top edge  30  of the front wall  14 , the upper edges  46  of the first  38  and second  42  side gussets, the upper edges  142  of the at least one pair of first side folded portions  138 ,  154  and the at least one pair of second side folded portions  158 ,  162  and the top edge  30  of the rear wall  18  together. The lower seam  62  seals the bottom edge  34  of the front wall  14 , the lower edges  50  of the first  38  and second  42  side gussets, the lower edges  146  of the at least one pair of first side folded portions  138 ,  154  and the at least one pair of second side folded portions  158 ,  162  and the bottom edge  34  of the rear wall  158 ,  162  together. 
     In order to demonstrate the utility of the present invention, a series of laboratory tests were conducted on thermoplastic bag film of differing thicknesses. When used in the manufacture of merchandise bags, plastic film needs to be resistant to both sudden puncturing and to tearing under load. In order to test the film for puncture resistance, a Dart Test, known as ASTM D1709, is employed. These test methods cover the determination of the energy that causes film to fail under specified conditions of impact of a free-falling dart. This energy is expressed in terms of the weight (mass) of the missile falling from a specified height which would result in 50% failure of specimens tested. Test Method A was employed for the results shown below. Test Method A employs a dart with a 38.10±0.13-mm (1.500±0.005-in.) diameter hemispherical head dropped from a height of 0.66±0.01 m (26.0±0.4 in.). This test method may be used for films whose impact resistances require masses of about 50 g or less to about 2 kg to fracture them. 
     The Method A test was performed on 0.4 mil and 0.8 mil plastic bags with the result that the 0.4 mil bag required a 235 gram dart to rupture the bag film while the 0.8 mil bag required a 315 gram to cause rupture. Thus the 0.8 mil bag required approximately 134% more weight to rupture than did the 0.4 mil bag film. This result is shown below in  FIG. 18 . This test procedure is particularly useful in gauging a bag&#39;s resistance to puncturing due to objects being dropped into the bag while the bag is suspended, as from a dispensing rack. As a puncturing force of this type is typically seen as a downward force against a bag&#39;s bottom or the joining of its side walls, making the bag walls out of a heavier plastic film can result in a bag having strength greater than or equal to a bag made of a uniform thickness plastic film that is thinner than the heavier plastic walls of the present invention. A bag made according to the design of the present invention will be strong in the critical areas where such strength is needed and thinner in those areas where such strength is either not needed or found in other features of the invention, such as multi-layered handles. 
     In order to test the film for tear resistance, the Standard Test Method for Propagation Tear Resistance of Plastic Film and Thin Sheet by Pendulum Method, as described in ASTM D 1922, was employed. This test method covers the determination of the average force to propagate tearing through a specified length of plastic film or nonrigid sheeting after the tear has been started, using an Elmendorf-type tearing tester. This tester involves a relatively dull knife attached to a weighted pendulum arm that impinges upon the sheet or film surface. In the present case weights of 400 grams and 800 grams were attached to the pendulum. The Tear Resistance test was performed on 0.4 mil and 0.8 mil plastic bags using the MD (in line) and TD (transverse) orientations of the test film. For the MD orientation, the 0.4 mil film required an average of 4.5 grams of force to tear the film while the 0.8 mil film required and average of 11.4 grams of force to tear. 
     For the TD orientation, the 0.4 mil film required an average of 52 grams of force to tear the film while the 0.8 mil film required and average of 99 grams of force to tear. Thus for either orientation, the 0.8 mil film required approximately twice the force to tear as did the 0.4 mil film. Note that the standard deviation for the force required to tear the film in the TD (transverse) direction is, on average 13-54 times greater that in the MD (inline) direction. This is usually a result of the uniformity of bonds in the plastic film in the inline direction being substantially greater than that in the transverse direction. This result is shown below in  FIG. 19 . Here, using the heavier, 0.8 mil film in those areas of the bag most subject to tearing force, namely the front and rear bag walls will provide sufficient strength while allowing use of a lighter film for less sensitive areas, such as the bag handles. The present invention calls for multiple bag handles which thus can be made of a thinner film. In addition, the bag handles are typically not subject to puncture or tearing forces, but only tensile forces. The use of multiple layers for the bag handles has been found to provide adequate tensile strength even when the handles are formed of thinner than normal plastic film. 
     Conventional gusseted bags have two point of inherent weakness on the lower seam at the points where the gusseted portion meets the ungusseted portions of the bag walls. The reason for this is that conventional gusseted bags are made of film of uniform thickness. In a bag having a single gusset at each side, when the bags are being formed and the gussets are folded in place, there will be four layers of plastic in the gusseted portions of the bag while there will be only two layers in the center, ungusseted portion of the bag. When the lower edge of the bag is heat sealed, there will be twice as much material to heat seal together at the gusseted portions as at the ungusseted portion. This leads to compromises as to the temperature and pressure to apply to the lower seam of the bag so as to join all four layers in the gusseted portions while not overheating and damaging the ungusseted portion. 
     In the present invention, in which the gusseted portions of the bag can be approximately half of the film thickness as the ungusseted portions, a single side gusset bag will have substantially the same thickness for the four layers in the gusseted portions of the bag as for the two layers in the ungusseted portion. As a result, heat and pressure used in forming the lower seam of the bag can be optimized for the strongest possible bag bottom. The present invention also provides for bag designs that include folded in gussets and multiple gussets. The reduction in thickness of the film used in the gusseted portions of the bags is particularly important for these designs as they would otherwise have much more significant differences in thickness of the layers to be sealed together to form a bag bottom. 
     The improved merchandise  8 , gusseted merchandise  13  and improved T-Shirt style  10  bags have been described with reference to particular embodiments. Other modifications and enhancements can be made without departing from the spirit and scope of the invention. For example, bags have been shown with one and three side gussets and well as bags with front walls folded into the side gusset. Bags could also be constructed with additional side gussets for increased handle strength.