Patent Publication Number: US-2006013514-A1

Title: Vacuum packaging bags with gussets and methods for using and manufacturing vacuum packaging bags with gussets

Description:
TECHNICAL FIELD  
      The present invention generally relates to vacuum packaging. More particularly, the invention is directed to vacuum packaging bags with gussets and methods for using and manufacturing vacuum packaging bags with gussets.  
     BACKGROUND  
      Vacuum packaging involves removing air or other gases from a storage container and then sealing the container to prevent the contents from being exposed to ambient air. Vacuum packaging is particularly useful in protecting food and other perishables against oxidation. Oxygen is a main cause of food spoilage and contributes to the growth of bacteria, mold, and yeast. Accordingly, vacuum-packaged food often lasts three to five times longer than food stored in ordinary containers. Moreover, vacuum packaging is useful for storing clothes, photographs, silver, and other items to prevent discoloration, corrosion, rust, and tarnishing. Vacuum packaging also produces tight, strong, and compact packages, reducing the bulk of articles and allowing for more space to store other supplies.  
       FIGS. 1A and 1B  are schematic isometric views of a conventional appliance  10  for vacuum packaging an object  98  (shown in broken lines) in accordance with the prior art. The vacuum packaging appliance  10  includes a base  20 , a lid  40  pivotably coupled to the base  20 , a lower trough  22  in the base  20 , an upper trough (not shown) in the lid  40 , and a vacuum pump (not shown) operably coupled to the upper trough. The lid  40  pivots between an open position (shown in  FIG. 1B ), in which a portion of a bag  60  can be placed between the lid  40  and the base  20 , and a closed position (shown in  FIG. 1A ), in which the bag  60  can be evacuated and thermally sealed. In the closed position, the upper trough and the lower trough  22  are aligned and form a vacuum chamber to remove gas from the interior of the bag  60 . The base  20  includes a seal  24  surrounding the vacuum chamber to seal the chamber from ambient air while gas is removed from the interior of the bag  60 . The vacuum packaging appliance  10  further includes a heating element  35  to thermally seal the bag  60  after the gas has been evacuated. A vacuum packaging appliance of this type is disclosed in U.S. Pat. No. 4,941,310, which is hereby incorporated by reference in its entirety.  
      Conventional vacuum packaging bags include two panels attached together with an open end. Typically, the panels each include two or more layers. The inner layer can be a heat sealable material, and the outer layer can be a gas impermeable material to provide a barrier against the influx of air. The plasticity temperature of the inner layer is lower than the outer layer. As such, the bag can be heated to thermally bond the inner layer of each panel together to seal the bag without melting or puncturing the outer layer.  
      A conventional vacuum packaging process includes depositing the object  98  into the bag  60  and positioning an open end  62  of the bag  60  in the lower trough  22  of the vacuum packaging appliance  10 . Next, the lid  40  pivots downward to form the vacuum chamber with the open end  62  of the bag  60  disposed within the vacuum chamber. The vacuum pump then removes gas from the vacuum chamber and the interior of the bag  60 , which is in fluid communication with the vacuum chamber. After gas has been removed from the interior of the bag  60 , the heating element  30  heats a strip of the bag  60  proximate to the open end  62  to bond the inner layer of each panel together and thermally seal the bag  60 .  
      One problem with conventional vacuum packaging bags is that bags configured to store bulky objects have big panels, which require a large vacuum packaging appliance to evacuate and seal. Large appliances have relatively big footprints and consume significant space on a countertop or other surface. For example, the footprint of the appliance  10  illustrated in  FIGS. 1A-1B  is the surface area of the bottom of the base  20 . Accordingly, there is a need to provide vacuum packaging appliances with smaller footprints.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIGS. 1A and 1B  are schematic isometric views of a conventional appliance for vacuum packaging objects in accordance with the prior art.  
       FIG. 2  is a schematic isometric view of a vacuum packaging system including a vacuum packaging appliance and a vacuum packaging bag in accordance with one embodiment of the invention.  
       FIG. 3  is a schematic front isometric view of the vacuum packaging bag of  FIG. 2 .  
       FIG. 4  is an enlarged schematic cross-sectional side view of a portion of the vacuum packaging bag of  FIG. 2  with the first and second panels pressed together.  
       FIG. 5  is a schematic front isometric view of a vacuum packaging bag in accordance with another embodiment of the invention.  
       FIG. 6  is a schematic front isometric view of a vacuum packaging bag in accordance with another embodiment of the invention.  
       FIG. 7  is a schematic front isometric view of a bag roll for forming vacuum packaging bags in accordance with another embodiment of the invention.  
       FIG. 8  is a flow chart illustrating a method of using vacuum bags according to one aspect of the invention. 
    
    
     DETAILED DESCRIPTION  
      A. Overview  
      The present invention is directed toward vacuum packaging bags and methods of manufacturing and using vacuum packaging bags. In one embodiment, a vacuum packaging bag includes a first panel, a second panel coupled to the first panel, and a gusset between the first and second panels. The first panel has a first gas impermeable layer and a first sealable layer coupled to the first gas impermeable layer. The second panel has a second gas impermeable layer and a second sealable layer coupled to the second gas impermeable layer. The gusset can extend along a length of the bag and project inwardly toward an interior region.  
      In another embodiment, a vacuum packaging bag includes a first panel and a second panel coupled to the first panel. The first panel has a plurality of intercommunicating channels, a first edge, a second edge opposite the first edge, a first gas impermeable layer, and a first sealable layer coupled to the first gas impermeable layer. The second panel has a third edge, a fourth edge opposite the third edge, a second gas impermeable layer, and a second sealable layer coupled to the second gas impermeable layer. The bag further includes a first gusset between the first and third edges and a second gusset between the second and fourth edges. In one aspect of this embodiment, the sealable layers are formed of a material such that the first sealable layer pealably bonds with the second sealable layer under the influence of heat and/or pressure. The sealable layers may also be formed of a material such that the first sealable layer permanently bonds with the second sealable layer.  
      The following disclosure describes several embodiments of vacuum packaging bags and methods of manufacturing and using vacuum packaging bags. Several details describing structures and processes that are well known and often associated with vacuum packaging appliances and bags are not set forth in the following description for purposes of brevity. Moreover, although the following disclosure sets forth several embodiments of different aspects of the invention, several other embodiments of the invention can have different configurations or different components than those described in this section. As such, it should be understood that the invention may have other embodiments with additional elements or without several of the elements described below with reference to  FIGS. 2-8 .  
      B. Embodiments of Vacuum Packaging Systems Including Vacuum Packaging Bass and Vacuum Packaging Appliances  
       FIG. 2  is a schematic isometric view of a vacuum packaging system  100  including a vacuum packaging appliance  110  and a vacuum packaging bag  160  in accordance with one embodiment of the invention. The vacuum packaging appliance  110  includes a base  120 , a lid  140 , and a hinge  150  pivotably coupling the lid  140  to the base  120 . The lid  140  is pivotable about an axis A-A between an open position (shown in  FIG. 2 ) and a closed position. The illustrated base  120  includes a first chamber portion  122  and a first seal  124  surrounding the first chamber portion  122 . The lid  140  can include a second chamber portion  142  and a second seal  144  surrounding the second chamber portion  142 . When the lid  140  is in the closed position, the first and second chamber portions  122  and  142  form a vacuum chamber. In other embodiments, the vacuum packaging appliance  110  can have other configurations. For example, the base  120  and/or the lid  140  might not include a chamber portion and/or a seal. Moreover, the vacuum packaging appliance  110  may be lidless.  
      The vacuum packaging appliance  110  further includes a vacuum pump  130  (shown in broken lines) operably coupled to the first and/or second chamber portion  122  or  142  for removing gas from the vacuum chamber when the lid  140  is in the closed position. The vacuum pump  130  can also remove gas from the interior of the bag  160  when an open end  162  of the bag  160  is positioned in the vacuum chamber. The bag  160  is configured so that the interior of the bag  160  is in fluid communication with the vacuum chamber when the lid  140  is in the closed position, as described in greater detail below with reference to  FIG. 4 . Accordingly, the vacuum pump  130  can remove gas from the vacuum chamber and the interior of the bag  160 .  
      In the illustrated embodiment, the vacuum packaging appliance  110  further includes a heating element  135  and a member  155  for pressing the bag  160  against the heating element  135 . The heating element  135  can be carried by the base  120 , and the member  155  can be carried by and project from the lid  140 . The heating element  135  is configured to thermally seal the bag  160  after the gas has been substantially evacuated from the interior of the bag  160 . The heating element  135  heats the bag  160  and the member  155  presses the bag  160  against the heating element  135  to ensure a seal is formed across the bag  160 . In other embodiments, the vacuum packaging appliance  110  can have a different configuration.  
      C. Embodiments of Vacuum Packaging Bags Having Gussets  
       FIG. 3  is a schematic front isometric view of the vacuum packaging bag  160  of  FIG. 2 . The bag  160  includes a first panel  164  and a second panel  174  coupled to the first panel  164 . The first panel  164  can include a first edge  168   a , a second edge  168   b , a third edge  168   c  opposite the first edge  168   a , and a fourth edge  168   d  opposite the second edge  168   b . The second panel  174  can include a first edge  178   a , a second edge  178   b , a third edge  178   c  opposite the first edge  178   a , and a fourth edge  178   d  opposite the second edge  178   b . In the illustrated embodiment, the second edge  168   b  and the third edge  168   c  of the first panel  164  are attached to the second edge  178   b  and the third edge  178   c , respectively, of the second panel  174 . The fourth edges  168   d  and  178   d  of the first and second panels  164  and  174  are unconnected and define the open end  162  of the bag  160 . The first and second panels  164  and  174  define an interior region  184  into which an object(s) can be placed.  
      The illustrated vacuum packaging bag  160  further includes a gusset  190  between the first and second panels  164  and  174 . The gusset  190  has a first portion  191   a  attached to the first panel  164  at the first edge  168   a  and a second portion  191   b  attached to the second panel  174  at the first edge  178   a . The illustrated gusset  190  extends along a length L of the bag  160  and projects inwardly toward the interior region  184  when the bag is empty. In other embodiments, such as the embodiments described below with reference to  FIGS. 5-6 , the bag may include a different number of gussets and/or the gusset may extend along a width of the bag.  
      One advantage of the illustrated bag  160  is that the gusset  190  increases the storage capacity of the bag  160 . The storage capacity is increased because the gusset  190  allows the first and second panels  164  and  174  to move a greater distance apart from each other. More specifically, as objects are placed into the interior region  184 , an angle α between the first and second portions  191   a - b  increases and the gusset  190  moves in a direction D 1  so that the first and second panels  164  and  174  can move away from each other. As such, the bag  160  can carry a greater volume of objects. Although the storage capacity of conventional bags can be increased by increasing the size of the panels, the larger panels require a bigger vacuum packaging appliance to evacuate and seal the bag. Bigger vacuum packaging appliances have larger footprints and require more space on the countertop or other surface. The gusset  190  in the illustrated bag  160 , however, increases the storage capacity of the bag  160  without increasing the size of the panels. Consequently, the bag  160  can be evacuated and sealed by an appliance with a smaller footprint.  
      Another feature of the illustrated bag  160  is that as an object is placed into the bag  160  and the first and second panels  164  and  174  move apart, the first and second panels  164  and  174  remain generally flat and, consequently, the footprint of the first and second panels  164  and  174  does not change significantly. An advantage of this feature is that the generally flat panels are easier to seal together in a vacuum packaging appliance. In contrast, when an object is placed in a conventional bag that does not have a gusset, the panels curve to increase the interior volume of the bag and, consequently, the footprint of the panels is reduced. The open end of these conventional bags is more difficult to seal.  
       FIG. 4  is an enlarged schematic cross-sectional side view of a portion of the vacuum packaging bag  160  with the first and second panels  164  and  174  pressed together. The first and second panels  164  and  174  each include a gas impermeable layer  180  (identified individually as  180   a - b ) and a sealable layer  182  (identified individually as  182   a - b ) coupled to the corresponding gas impermeable layer  180 . The gas impermeable layers  180   a - b  provide a barrier against the influx of air. The sealable layers  182   a - b  can have a different temperature of plasticity than the gas impermeable layers  180   a - b  so that the bag  160  can be heated to bond the sealable layers  182   a - b  together without melting or puncturing the gas impermeable layers  180   a - b . In other embodiments, the first and second panels  164  and  174  can further include an additional layer(s), such as a structural layer, to increase the strength and rigidity of the bag  160 .  
      The sealable layers  182  can include a pealably sealable layer and/or a substantially permanently sealable layer. The pealably sealable layer includes resin or other materials that through pressure, heat, or another sealing enabler, form a pealable seal that is opened through a manual pealing action. The manual pealing action does not require a tool and does not result in wasting or destroying a portion of the vacuum packaging bag. Pealably sealable layers are described in detail in U.S. Provisional Patent Application No. 60/553,693, filed Mar. 15, 2004, which is incorporated by reference herein. Permanently sealable layers can include resin that with heat forms a generally permanent seal. In several embodiments, the sealable layers  182  can include a material which when heated to a first temperature forms a pealable seal and when heated to a second temperature forms a permanent seal.  
      In the illustrated embodiment, the second panel  174  includes a plurality of intercommunicating channels  175  configured to exhaust gas from the interior of the bag  160  when the first and second panels  164  and  174  are pressed together as shown in  FIG. 4 . Accordingly, when the lid  140  ( FIG. 2 ) of the vacuum packaging appliance  110  ( FIG. 2 ) is in the closed position and the bag  160  is sandwiched between the first and second seals  124  and  144  ( FIG. 2 ), gas can be evacuated from the interior region  184  ( FIG. 3 ) of the bag  160  through the channels  175 . In other embodiments, the second panel  174  may not include the channels  175 .  
       FIG. 5  is a schematic front isometric view of a vacuum packaging bag  260  in accordance with another embodiment of the invention. The bag  260  illustrated in  FIG. 5  is generally similar to the bag  160  described above with reference to  FIG. 3 . For example, the illustrated bag  260  includes a first panel  164 , a second panel  274  coupled to the first panel  164 , and a first gusset  190  between the first and second panels  164  and  274 . The illustrated bag  260 , however, does not include a plurality of intercommunicating channels in the second panel  274 . Moreover, the illustrated bag  260  includes a second gusset  293  between the first and second panels  164  and  274  and opposite the first gusset  190 . The second gusset  293  includes a first portion  294   a  attached to the first panel  164  at the third edge  168   c  and a second portion  294   b  attached to the second panel  274  at the third edge  178   c . The first and second gussets  190  and  293  accordingly increase the storage capacity of the bag  260 . In other embodiments, the first and/or second panel  164  and/or  274  of the bag  260  may include a plurality of intercommunicating channels to facilitate the evacuation of gas from the bag  260 .  
       FIG. 6  is a schematic front isometric view of a vacuum packaging bag  360  in accordance with another embodiment of the invention. The bag  360  illustrated in  FIG. 6  is generally similar to the bag  260  described above with reference to  FIG. 5 . For example, the illustrated bag  360  includes a first panel  164 , a second panel  274 , a first gusset  190 , and a second gusset  293 . The illustrated bag  260 , however, further includes a third gusset  396  between the first and second panels  164  and  274 . The third gusset  396  includes a first portion  297   a  attached to the first panel  164  at the second edge  168   b  and a second portion  297   b  attached to the second panel  274  at the second edge  178   b . The first, second, and third gussets  190 ,  293 , and  369  accordingly increase the storage capacity of the bag  360 .  
       FIG. 7  is a schematic front isometric view of a bag roll  461  for forming vacuum packaging bags in accordance with another embodiment of the invention. The illustrated bag roll  461  includes a first sheet  466 , a second sheet  476  coupled to the first sheet  466 , and an open end  462 . The first sheet  466  includes a first edge  468   a  and a second edge  468   c  opposite the first edge  468   a , and the second sheet  476  includes a first edge  478   a  and a second edge  478   c  opposite the first edge  478   a . The first and second sheets  466  and  476  can include gas impermeable layers and sealable layers, similar to those described above with reference to  FIG. 4 . The bag roll  461  further includes (a) a first gusset  490  between the first edge  468   a  of the first sheet  466  and the first edge  478   a  of the second sheet  476 , and (b) a second gusset  493  between the second edge  468   c  of the first sheet  466  and the second edge  478   c  of the second sheet  476 . Bags are formed from the bag roll  461  by pulling out a portion of the first and second sheets  466  and  476 , cutting the sheets  466  and  476 , for example, along line B-B, and sealing one of the open ends.  
       FIG. 8  is a flow chart illustrating a method  500  according to one aspect of the invention. The method  500  begins at step  502  wherein a user cuts a portion of a bag roll, such as described above with reference to  FIG. 7 . In step  504 , the user seals one of the two open ends of the portion of the bag roll. The step  504  may involve applying heat, pressure, or both, in a predefined range and for a predefined time period. For example, the end can be pealably or permanently sealed with the heating element  135  of the vacuum packaging appliance  110 . If a user is using a preformed bag, however, the steps  502  and  504  are unnecessary. In step  506 , the user places an object into the bag. In step  508 , the user evacuates the bag. Evacuation typically involves placing the open end of the bag in the vacuum chamber of an appliance and closing the lid of the appliance. In step  510 , the open end of the bag is sealed. The seal can be a pealable or permanent seal as described above with reference to the step  504 . In step  512 , the user stores the object in the sealed bag as desired.  
      As the side-gusseted portion of the bag has additional bag material, sealing tends to require more energy than bags not having the extra thickness of the side-gussets. This is not a difficult problem to compensate for, simply meaning that more energy must be used and perhaps users should be aware of this requirement to ensure that seals are properly made. Additionally, the side-gusseted bag may best be made from PE or PP materials as these seal more readily than competing nylon materials. However, any suitable material may be used as long as the proper care is taken.  
      From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.