Patent Document

CROSS REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority in Provisional Application Ser. No. 60/852,196, filed Oct. 17, 2006, entitled “Bags with Reduced Size Gussets”. The full disclosure of that application is hereby incorporated by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not applicable. 
     TECHNICAL FIELD 
     The present invention relates to bottom sealed bags, and more particularly to side gusseted bottom seal bags. 
     BACKGROUND OF THE INVENTION 
     Technical Problems Posed by the Prior Art 
     There are, of course, many different types of bags used for many different applications. For example, bags are often used by individuals to carry their items. Such items may come in many different shapes and sizes, and bags are provided to accommodate such varying items. Further, bags are often used in a wide variety of manufacturing processes, including automatic filling processes. 
     Bags with gussets on the sides, for example, are provided to enable the bag to be stored flat with a width which is substantially less than half its opening perimeter. Moreover, gussets may be used to assist in defining the bag shape whereby, for example, the body of the bag may be opened to provide a carrying space with a circumference which is substantially greater than twice the width of the bottom of the bag. Bags with gussets on the sides are also often advantageously used in automatic filling processes 
     However, while gussets may provide some advantages and meet specific objects at certain parts of the bag, they may also be less advantageous or even undesirable at other parts of the bag. 
     For example, interrupted gussets may be advantageously used in automatic filling processes, with such bags being easier to open, fill and seal/close after filling in such processes. 
     Further, interrupted gussets may be advantageous in other uses as well. That is, while gussets assist in providing maximum storage space in the bottom portion of the bag, they can be disadvantageous at the top opening of the bag where the gusseted shape may make it difficult to place items in the bag. A bag user may, for example, find the gusset to be difficult to position properly at the top opening where the gusset is most free to fold in or out. A gusset which is unintentionally folded into the top opening may snag on an item being placed in the bag. Further, a gusset along the bag may leave the top opening too big, allowing items contained in the bag to fall out too easily, or be readily taken without notice by thieves. Still further, while gussets when properly folded with the bag in a flat condition are advantageous in providing an easily storable shape, folding bags flat with the gussets in the proper position is often difficult and/or time consuming, particularly when handling many such bags. In fact, gussets in bags are often advantageous but, for varying reasons, may not be advantageous at every location along the bag. 
     However, particularly given the continuous nature of bag manufacturing materials, bags with gussets have been made most efficiently with gussets extending along the complete height of one or more sides of the bag. Manufacturing bags with interrupted gussets can be difficult and/or inefficient. 
     WO 2006/092517 A1 discloses a bag structure in which the gusset is stopped by cutting off the gusset panels from the open end of the bag to the position at which the gusset is desired to start, and then resealing the side edges of both sides of the bag where the gussets were removed. This structure limits the flexibility of the positioning of the gusset ends, and further may weaken the bag where the edges are resealed. The gusset ends are formed by cutting the gusset panels and folding them down. Folded gusset ends are also disclosed in WO 2005/105592 A1 and DE 20 2004 006 856 U1. 
     EP 0 834 454 A1 also discloses a bag with gusset-type sides which end before the top opening of the bag. This structure uses a single patch to close both open gussets, and requires special triangular transitions in which all four panels at that location must be each sealed together. 
     U.S. Pat. No. 6,261,000 B1 discloses a bag with gussets in which cutouts are formed in the gussets to discontinue them, with the edges of the cutouts heat sealed. However, it can be difficult to heat seal along those edges without risking heat sealing of adjacent areas which are not desired to be sealed. 
     The present invention is directed toward overcoming one or more of the problems set forth above. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an advantageous method for manufacturing bags having gussets which are interrupted at one or more location along the side of the bag. 
     According to the present invention, the method of forming a bag with at least one gusset on one side includes the steps of (a) forming a bag blank having a front panel and a back panel connectable along opposite sides, (b) forming a gusset along one side of one of the front and back panels, the gusset comprising first and second gusset panels inwardly V-folded, which gusset panels have a removable gusset portion at a selected position on the one side, (c) adhesively adhering one side of a patch to one of the gusset panels to a location adjacent the removable gusset portion, the patch having a second adhesive on portions extending beyond the one gusset panel location to the removable gusset portion and beyond the V-fold, (d) removing the removable gusset portion from the gusset, and (e) adhering the second adhesive on the one side of the patch extending portions to facing portions of one of the front and back panel. 
     In a further form, the first and second patches are aligned on opposite sides of the bag. 
     In another form, the step of adhering the second adhesive comprises ultrasonic sealing. 
     In yet another form, the second adhesive is thermoadhesive on the one side of the patch, and the step of adhering the second adhesive comprises heating the patch while pressing the patch against the back panel. 
     In a still further form, the method further consists of (b1) forming a second gusset along the other side of one of the front and back panels, the second gusset comprising third and fourth gusset panels inwardly V-folded, which gusset panels have a removable second gusset portion at a selected position on the side, (c1) adhesively adhering one side of a second patch to one of the third and fourth gusset panels to a location adjacent the removable second gusset portion, the second patch having thermoadhesive on the one side and portions extending beyond the third and fourth gusset panel location to the removable second gusset portion and beyond the V-fold, (d1) removing the removable second gusset portion from the second gusset, and (e1) heating the second patch to adhere the one side of the second patch extending portions to facing portions of one of the front and back panel. 
     In another aspect of the present invention, a gusseted bag is provided including a front panel having opposite sides between an open end and a closed end, a back panel having opposite sides between an open end and a closed end and respectively connected to the front panel opposite sides, and a gusset connecting a part of one side of the front and back panels on one of the opposite sides. The gusset includes first and second gusset panels inwardly V-folded and terminating at an end short of one of the front and back panel ends. A patch is adhered to one of the gusset panels and to one of the front and back panels, and is adhered (a) to the one gusset panel whereby the first and second gusset panels are both between the patch and the one of front and back panels, and (b) to the one of the front and back panels adjacent the gusset short end and adjacent the V-fold of the one gusset panel. 
     In one form of this aspect of the present invention, the patch is adhered by ultrasonic sealing to the one of the front and back panels adjacent the gusset short end and adjacent the V-fold of the one gusset panel. 
     In another form of this aspect of the present invention, the patch is thermo-adhered to the one of the front and back panels adjacent the gusset short end and adjacent the V-fold of the one gusset panel. 
     In still another form of this aspect of the present invention, a second gusset connects a part of the other side of the front and back panels on one of the opposite sides, where the second gusset includes third and fourth gusset panels inwardly V-folded and terminating at an end short of one of the front and back panel ends. A second patch is spaced from the first patch and adhered to one of the third and fourth gusset panels and to one of the front and back panels, wherein the second patch is adhered (a) to the one gusset panel whereby the third and fourth gusset panels are both between the second patch and the one of front and back panels, and (b) to the one of the front and back panels adjacent the gusset short end and adjacent the V-fold of the one gusset panel. In a further form, the first and second patches are aligned on opposite sides of the bag. 
     In still another aspect of the present invention, a method of forming a bag with at least one gusset on one side is provided, including (1) forming a bag blank having a front panel and a back panel connectable along opposite sides, (2) forming a gusset along one side of one of the front and back panels, the gusset comprising first and second gusset panels inwardly V-folded, (3) trimming off a fold connecting the front panel to the gusset and separating the front panel from the back panel and gusset to expose the front of the back panel and gusset, (4) removing a gusset portion at a selected position on the one side, (5) adhesively adhering a first patch to one of the gusset panels and the back panel, and (6) adhering the front panel along both of its sides to the gusset and back panel. 
     In a further form of this aspect of the invention, a second gusset is formed along the other side of the one of the front and back panels, and a second patch separate from the first patch is adhesively adhered to the back panel and second gusset. 
     In another form of this aspect of the invention, a zipper is formed between sides of at least one of the front and back panels where the gusset portions are removed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a web of material following an initial step of the manufacturing process disclosed herein; 
         FIG. 2  is a plan view similar to  FIG. 1 , showing a further step of the manufacturing process with the patches applied to the web of material; 
         FIG. 3  is a perspective view of the web of material of  FIG. 2  after an initial folding step; 
         FIG. 4  is a perspective view of the web of material according to  FIG. 3  after the gusset portions have been tucked out; 
         FIG. 5  is a plan view of the web of material according to  FIG. 4  with the gussets folded flat and adhered in place by panels according to the present invention; 
         FIG. 6  is a top view of the web of  FIG. 5 ; 
         FIG. 7  is a top view similar to  FIG. 6  with the front panel folded over to close the bag; 
         FIGS. 8A to 8D  illustrate different bags having gussets variously interrupted in accordance with the present invention; 
         FIG. 9  is a plan view of a web of material following an initial step of an alternate manufacturing process disclosed herein; 
         FIG. 10  is an end, cross-sectional view of the web of material of  FIG. 9  after folding; 
         FIG. 11  is a view similar to  FIG. 10 , after one fold is trimmed according to the present invention; 
         FIG. 12  is a view of the web according to  FIG. 11 , with the front panel separated from the back panel and gussets for further manufacturing steps; 
         FIG. 13  is a plan view of the back panel and gussets of  FIG. 12 , with sections of the gussets removed according to the present invention; 
         FIG. 14  is a plan view showing patches added to the structure of  FIG. 13 ; and 
         FIG. 15  is an end, cross-sectional view showing the front panel brought back to the back panel and gussets for reattaching according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-7  illustrate the process steps of making a bag with an interrupted gusset according to the present invention. 
     As illustrated in  FIG. 1 , a longitudinally extending flat web of material  10  (extending vertically) is provided from which a series of bags may be formed such as is generally known. The web of material  10  may be supplied in any suitable manner including, for example, a standard Hudson-Sharp Machine Co. model SDU 1600 unwind stand, which has an electrical surface driven and braked unwind with a compensator for perfect web tension control. Such web guide system may advantageously provide a suitably centered web at the exit to the unwind. 
     The material web  10  may advantageously include multiple layers in which one of the outer layers (i.e., the upwardly facing side in  FIG. 1 ) has thermoadhesive properties. 
     Handling of the web  10  may be accomplished in any suitable manner, such as a dancer system with driven nip rollers (not shown) followed by a set of driven draw rolls operated to intermittently move the web  10  such as is known by those skilled in the art. 
     As the web  10  is advanced by, for example, the draw rolls, a number of actions are taken on the web  10  in the direction of arrow  12 . 
     Four perforations are made in the web  10  along lines  22 ,  24 ,  26 ,  28 , with the perforations extending laterally across the web  10  relative to five longitudinally extending folds  30 ,  32 ,  34 ,  36 ,  38  which will later be formed as described below. The location of the folds  30 ,  32 ,  34 ,  36 ,  38  are shown in  FIGS. 1-2  for orientation purposes. Specifically, two perforations  22 ,  24  are longitudinally spaced apart and extend from one edge of the web  10  past fold  30  to fold  32 . The other two perforations  26 ,  28  are similarly longitudinally spaced apart and extend from fold  34  past fold  36  to fold  38 . Such perforations  22 ,  24 ,  26 ,  28  may be formed in a suitable manner, for example, between intermittent movements of the web  10 , and define removable gusset portions  40 ,  42 . 
     After the perforations  22 ,  24 ,  26 ,  28  are formed, two separate patches  50 ,  52  are applied as shown in  FIG. 2 , being adhered only at the areas  54 ,  56 . The patches  50 ,  52  as illustrated are thermoadhesive on both sides, and the adhesion at areas  54 ,  56  may be accomplished via thermoadhesion. However, it should be understood that it would be within the scope of the present invention to adhere the patches via any suitable manner which will hold the patches  50 ,  52  in place, including not only thermoadhesion, but also glue spots, hot melt, self adhesion, ultrasonic sealing or even static electricity. The use of separate patches  50 ,  52  for each gusset is advantageous particularly where bags are produced on machines which make the bag in the longitudinal direction. 
     The previously described folds  30 ,  32 ,  34 ,  36 ,  38  may then be suitably formed via any suitable folding technique, such as folding plates, folding triangles, and the like. When so folded as shown in  FIG. 3 , gussets  60 ,  62  are suitably formed along the material web  10  on opposite sides of a back or rear panel  70 , including between one side of the back panel  70  and the front panel  72 . (It should be appreciated that the designation front and back are used here for convenience of reference, and it does not matter within the scope of the present invention which of the panels  70 ,  72  is considered the front or the back.) 
     The first gusset  60  is on one side of the back panel  70 , and includes a pair of gusset panels  80 ,  82  which are inwardly V-folded as shown in  FIG. 3 . The second gusset  62  is between the back and front panels  70 ,  72 , and includes a pair of gusset panels  84 ,  86  which are also inwardly V-folded. 
     The folding is accomplished without folding the edges of the patches  50 ,  52 . By being adhered only at the areas  54 ,  56  on gusset panels  80 ,  86 , the patches  50 ,  52  will not fold relative to those panels  80 ,  86  with adjacent gusset panels  82 ,  84 . Further, suitable fingers or the like could be provided during the folding process to prevent folding of the patches  50 ,  52  if necessary in that process. 
     As illustrated in  FIG. 4 , the gusset portions  40 ,  42  are then removed by breaking the perforations  22 ,  24 ,  26 ,  28  and pulling the portions  40 ,  42  clear of the gussets  60 ,  62 . This can be accomplished, for example, by use of a suitable mechanical gripper which grasps the gusset portions  40 ,  42  at the fold lines  30 ,  36  and moves past the edges of the folded web  10 , causing the perforations  22 ,  24 ,  26 ,  28  to break as the portions  40 ,  42  tuck out. 
     Thereafter, as illustrated in  FIG. 5 , the patches  50 ,  52  are suitably secured to the web, with the portions of the patches  50 ,  52  projecting beyond the gusset panels  20 ,  86  to which they were previously adhered. With the gusset panels  80 ,  82  and  84 , 86  folded flat against the back panel  70 , the patches  50 ,  52  are thermally pressed against the back panel  70 . Due to the thermoadhesive surfaces, such heat and pressure essentially adheres the entire bottom surface of the patches  50 ,  52  to the gusset panels  80 ,  86  and the back panel  70 , thereby securing each gusset  60 ,  62  flat against the back panel  70  as illustrated in  FIG. 6 . Thus it should be appreciated that the gussets  60 ,  62  are effectively eliminated at those locations, so that the opening size of the bag will be restricted. 
     Still other methods of adhering could be used, including ultrasonic sealing, hot melt, self adhesive patches, and the like, so long as the patches  50 ,  52  may be first applied in a manner which adheres only to the areas  54 ,  56 , and the remainder of the patch surface later being adhered to the back panel  70  as described. 
     Finally, the front panel  72  is folded over as illustrated in  FIG. 7  (which folding can be accomplished by any suitable folding machine). The edge  90  of the front panel  72  may then be secured to the edge  92  of the gusset panel  80  at the overlap  94  to close the lateral boundary of the bag. 
     It should be appreciated that the sequence of steps as described above may be varied somewhat in accordance with the present invention. For example, the front panel  72  may be folded over before the gusset portions  40 ,  42  are tucked out and the patches  50 ,  52  fully adhered to the back panel  70 . 
     It should thus be appreciated that upon completion of the above steps the continuous web  10  will include a portion which is suitably secured to define an encircled longitudinal space. At this point, finishing operations such as are known to those skilled in the art may be accomplished, including operations like angle sealing, longitudinal sealing, cross sealing, handle cut outs and the like can also be carried out. Further, side trimming, of the gusset portions  40 ,  42 , and of the closing overlap  94  can also be accomplished, with the removed materials discarded as scrap. A longitudinal end may also be cut and suitably sealed so as to separate the above described portion from the continuous web  10  and thereby define a separate bag. 
     It should also be appreciated that the above method can be used to provide a variety of different bag designs, such as shown in  FIGS. 8A-8D .  FIG. 8A , for example, shows a bag design such as described above, with gussets extending along both sides, with the gussets being terminated on both sides near the top opening end of the bag  100 A.  FIG. 8B  illustrates a bag  100 B having only one end of one gusset interrupted, whereas  FIG. 8C  illustrates a bag  100 C having four interruptions (at both ends of two gussets) and  FIG. 8D  illustrates a bag  100 D having three interruptions. 
       FIGS. 9-15  illustrate the process steps of making a bag with an interrupted gusset according to another aspect of the present invention. 
     As illustrated in  FIG. 9 , a longitudinally extending flat web of material  110  (extending vertically) is provided from which a series of bags may be formed such as is generally known. The web of material  110  may be supplied in any suitable manner including, for example, a standard Hudson-Sharp Machine Co. model SDU 1600 unwind stand, which as previously mentioned has an electrical surface driven and braked unwind with a compensator for perfect web tension control. Such web guide system may advantageously provide a suitably centered web at the exit to the unwind. 
     The material web  110  may advantageously include multiple layers in which one of the outer layers (i.e., the upwardly facing side in  FIG. 9 ) may have thermoadhesive properties. 
     Handling of the web  110  may be accomplished in any suitable manner, such as a dancer system with driven nip rollers (not shown) followed by a set of driven draw rolls operated to intermittently move the web  110  such as is known by those skilled in the art. 
     As the web  110  is advanced by, for example, the draw rolls, a number of actions are taken on the web  110  in the direction of arrow  112 . 
     Sets of three laterally spaced aligned slits  121 ,  123 ,  125  are cut at spaced locations along the web  110 . A suitable zipper structure  127  may also be advantageously provided across the web  110  to provide a structure for closing the manufactured bag, which may include, for example, a slider element. 
     The web  110  includes five longitudinally extending folds  130 ,  132 ,  134 ,  136 ,  138  which will later be formed as described below, but are shown in  FIG. 8  for orientation purposes. The slits  121 ,  123 ,  125  are located on three of those folds, with slit  121  cut along fold  132 , slit  132  cut along fold  134  and slit  125  cut along fold  138 . Such slits  121 ,  123 ,  125  may be formed in a suitable manner, for example, during intermittent movements of the web  110 . 
     The folds  130 ,  132 ,  134 ,  136 ,  138  may then be suitably formed via any suitable folding technique, such as folding plates, folding triangles, and the like, as shown in  FIG. 10 , with gussets  160 ,  162  suitably formed along the material web  110  on opposite sides of a back or rear panel  170 , including between one side of the back panel  170  and the front panel  172 . (It should be appreciated that the designation front and back are used here for convenience of reference, and it does not matter within the scope of the present invention which of the panels  170 ,  172  is considered the front or the back.) 
     Fold  138  is then trimmed as shown in  FIG. 11  so as to effectively separate the front panel  172 , which may be moved clear of the back panel  170  and gussets  160 ,  162  as shown in  FIG. 12  so that access to the front of the back panel  170  may be had as shown in  FIG. 13 . 
     As also shown in  FIG. 13 , spaced sections of the gussets  160 ,  162  are also suitably removed by cutting laterally at opposite ends of the slits  121 ,  123  (as at reference numbers  173 ,  175 ,  177 ,  179 ). It should be understood that the cuts at  173 ,  175 ,  177 ,  179  could also be made earlier in the process (e.g., when the slits  121 ,  123 ,  125  are cut), making these cuts at this stage allow the trimmed material to be retained with the web  110  until they may be handled at this location in the manufacturing process. 
     Two separate suitable patches  181 ,  183  are then applied as shown in  FIG. 14  so as to seal each gusset length on one end. The patches  181 ,  183  may be thermoadhesive, and the adhesion to the gusset panels  191 ,  197  (trapping panels  193 ,  195 ) and to the back panel  170  may be accomplished via thermoadhesion. However, it should be understood that it would be within the scope of the present invention to adhere the patches via any suitable manner which will hold the patches  181 ,  183  in place, including not only thermoadhesion, but also glue spots, hot melt, self adhesion, ultrasonic sealing or even static electricity. The use of separate patches  181 ,  183  for each gusset is advantageous particularly where bags are produced on machines which make the bag in the longitudinal direction. Still other methods of adhering could be used, including ultrasonic sealing, hot melt, self adhesive patches, and the like. 
     Finally, the edge of the front panel  72  may then be secured to the edge of the gusset panels  191 ,  197  to close the lateral boundary of the bag (see  FIG. 15 . Separate bags may then be cut from the web  110  and also suitably sealed laterally (across the folded web) as is known in the art. 
     Still other aspects, objects, and advantages of the present invention can be obtained from a study of the specification, the drawings, and the appended claims. It should be understood, however, that the present invention could be used in alternate forms where less than all of the objects and advantages of the present invention and preferred embodiment as described above would be obtained.

Technology Category: 7