Patent Publication Number: US-7220053-B2

Title: Flexible composite bag for vacuum sealing

Description:
RELATED APPLICATION 
   This application claims priority to U.S. Provisional Patent Application No. 60/529,784, entitled, “F LEXIBLE  C OMPOSITE  B AG FOR  V ACUUM  S EALING ” by H ONGYU  W U , filed on Dec. 16, 2003, and which is hereby incorporated by reference in its entirety. 
   This application is related to application number 7,850, which issued as U.S. Pat. No. Re. 34,929, filed Jan. 22,1993 by inventor Hanns J. Kristen, the entire contents of which is hereby incorporated by reference as if fully set forth herein. 

   FIELD OF THE INVENTION 
   This invention relates to packaging materials for use with vacuum packaging machines. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: 
       FIG. 1  is a perspective view illustrating a composite bag comprising an inner bag within the cavity of an outer bag. 
       FIG. 2  is an enlarged perspective view illustrating the outer surface of the panels of the inner bag. 
       FIG. 3  is a cross-sectional view illustrating the structure of the outer bag and the inner bag according to one embodiment. 
       FIG. 4  is a cross-sectional view illustrating the structure of the inner bag according to one embodiment. 
       FIG. 5  is a cross-sectional view illustrating the structure of the outer bag and the inner bag according to another embodiment. 
       FIG. 6  is a cross-sectional view illustrating the structure of the outer bag and the inner bag according to yet another embodiment. 
       FIG. 7 ,  FIG. 8  and  FIG. 9  illustrate various patterns according to certain embodiments. 
       FIG. 10  and  FIG. 11  illustrate inner surfaces of panels of an inner bag. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  shows a flexible composite bag  100  that has an outer flexible bag  122  and an inner flexible bag  102 . Outer bag  122  has an open end  128 . Inner bag  102  has an open end  108 . When the open ends  128  and  108  are placed in an air tight vacuum channel (not shown) of a vacuum packaging machine (not shown), the air from the interior of the inner bag and from the space between the inner bag and the outer bag can be extracted by means of a vacuum pump that is operably connected to the vacuum channel. Vacuum packaging machines are well known in the art. Examples of vacuum packaging machines are FoodSaver® Appliances sold by Tilia, Inc. 
   Outer bag  122  has two panels, namely, a top panel  126  and a bottom panel  124 . Inner bag  102  has two panels, namely, a top panel  106  and a bottom panel  104 . Each panel of outer bag  122  and the inner bag  102  is made of two layers, according to certain embodiments. The two layers of a panel include an inner heat sealable layer with thermal properties, such as a thermoplastic material, and an outer gas-impermeable layer to provide a barrier against an influx of air to the interior of the bag. According to certain embodiments, the panels of the inner bag  102  and the outer bag  122  are joined together at opposite lateral sides thereof to define a chamber adapted to hold a product disposed therein. 
     FIG. 2  is an enlarged perspective view illustrating the outer surface of the panels of the inner bag  102 , according to certain embodiments.  FIG. 2  shows a crisscrossing channel design on the outer surface  152  of top panel  106 . The outer surface  162  of bottom panel  104  has the same crisscrossing design but is not completely visible in  FIG. 2 . 
   For example, as shown by top panel  106 , the crisscrossing channel design comprises a plurality of grooves  154  and a plurality of raised island-like protuberances  156 . The plurality of grooves  154  define intercommunicating channels entirely around and between the raised island-like protuberances  156 . Such a crisscrossing design is formed on both the inner surface  150  (inner layer) and outer surface  152  (outer layer) of top panel  106 . The bottom panel  104  has a similar or same crisscrossing channel design that comprises a plurality of grooves  164  and a plurality of raised island-like protuberances  166 . The plurality of grooves  164  define intercommunicating channels entirely around and between the raised island-like protuberances  166 . Such a crisscrossing design is formed on both the inner surface  160  (inner layer) and outer surface  162  (outer layer) of bottom panel  104 . 
   When the inner surface  160  of bottom panel  104  touches the inner surface  150  of top panel  106 , the bottom of channels of inner surface  160  of bottom panel  104  more or less coincide with the bottom of channels of the inner surface  150  of top panel  106 . The island-like-protuberances  166  of inner surface  160  of bottom panel  104  more or less forms a cup under the island-like-protuberances  156  of the inner surface  150  of top panel  106  when the inner surface  150  touch the inner surface  160 . Thus, island-like-protuberances  166  of inner surface  160  and the island-like-protuberances  156  of the inner surface  150  together form pockets of spaces, shown as pockets  450  in  FIG. 4 . In  FIG. 4 , the top panel  106  of the inner bag touches the bottom panel  104  of the inner bag. For example, the bottom portion of the groove  154  touches the bottom portion of groove  164 . 
   According to certain embodiments, when the inner bag  102  has a crisscrossing channel design as shown in  FIG. 2 , each panel of the outer bag  122  may be composed of flat layers of the same material as the layers of the panels of the inner bag. The outer bag is not shown in  FIG. 2 . 
     FIG. 3  is a cross-sectional view illustrating the structure of the outer bag and the inner bag according to one embodiment.  FIG. 3  shows the top panel  106  and bottom panel  104  of the inner bag.  FIG. 3  shows the cross-sectional views of the outer surface  152  (outer layer) and inner surface  150  (inner layer) that are both formed to make grooves  154  and the island-like-protuberances  156  of the crisscrossing channel design as previously described with reference to  FIG. 2 .  FIG. 3  also shows the cross-sectional views of the outer surface  162  (outer layer) and inner surface  160  (inner layer) that are both formed to make grooves  164  and the island-like-protuberances  166  of the crisscrossing channel design. Each island-like protuberance and each channel is shown as being trapezoidal, when viewed in cross section. The protuberances are formed in the panel to form a plurality of raised ridges of the outer surface thereof that project outwardly therefrom to define the channels therein. In the embodiment shown of  FIG. 3 , the outer surface areas of the ridges are at least generally flat and co-planar relative to each other. 
     FIG. 3  also shows the cross-sectional view of the top panel  320  of the outer bag and the bottom panel  310  of the outer bag. Top panel  320  is composed of a flat outer surface  322  (outer layer) and a flat an inner surface  324  (inner layer). Bottom panel  310  is composed of a flat outer surface  312  (outer layer) and a flat an inner surface  314  (inner layer). 
     FIG. 5  is a cross-sectional view illustrating the structure of the outer bag and the inner bag according to another embodiment.  FIG. 5  shows an embodiment where the top panel  106  and bottom panel  104  of the inner bag is as previously described with reference to  FIG. 3 . However, in  FIG. 5 , the top and bottom panels of the outer bag are not flat as described with reference to  FIG. 3 . In certain embodiments, as shown in  FIG. 5 , the top and bottom panels of the outer bag possess a crisscrossing channel design. However, as shown in  FIG. 5 , the crisscrossing channel design of the top and bottom panels of the outer bag is a mirror image of the crisscrossing channel design of the top and bottom panels of the inner bag as shown in  FIG. 5 . 
   To explain, the top panel  550  of the outer bag is composed of inner surface  558 , outer surface  560 , grooves  554  and island-like-protuberances  556 . The bottom panel  590  of the outer bag is composed of inner surface  568 , outer surface  570 , grooves  564  and island-like-protuberances  566 . When the inner surface  558  of top panel  550  of the outer bag touches the outer surface  152  of top panel  106  of the inner bag, the bottom of the island-like-protuberances of inner surface  558  will touch the bottom of the island-like-protuberances of outer surface  152 . The groove  554  of inner surface  558  more or less forms a cup over the groove  154  of the outer surface  152  when the outer surface  152  touches the inner surface  558 . Thus, grooves  554  and the grooves  154  together form pockets of spaces when the outer surface  152  touches the inner surface  558 . 
   Similarly, when the inner surface  568  of bottom panel  590  of the outer bag touches the outer surface  162  of bottom panel  104  of the inner bag, the bottom of the island-like-protuberances of inner surface  568  will touch the bottom of the island-like-protuberances of outer surface  162 . The groove  564  of inner surface  568  more or less forms a cup under the groove  164  of the outer surface  162  when the outer surface  162  touches the inner surface  568 . Thus, grooves  564  and the grooves  164  together form pockets of spaces when the outer surface  162  of bottom panel  104  of the inner bag touches the inner surface  568  of bottom panel  590  of the outer bag. 
     FIG. 6  is a cross-sectional view illustrating the structure of the outer bag and the inner bag according to yet another embodiment. In  FIG. 6 , the top surface areas of the island-like protuberances appear on the inner surfaces of the panels of the inner bag. Similarly, the channels also appear on the inner surfaces of the panels of the inner bag. 
   For example, when the inner surface  170  of top panel  179  of the inner bag touches the inner surface  180  of bottom panel  189  of the inner bag, the surface area of the island-like-protuberances  176  of inner surface  170  will touch the surface area of the island-like-protuberances of outer surface  186  of inner surface  180 . The groove  174  of inner surface  170  more or less forms a cup over the groove  184  of the inner surface  180  when the inner surface  170  of top panel  179  touches the inner surface  180  of bottom panel  189 . Thus, grooves  174  and the grooves  184  together form pockets of spaces when the inner surface  170  of top panel  179  touches the inner surface  180  of bottom panel  189  of the inner bag. 
   When the inner surface  688  of top panel  655  of the outer bag touches the outer surface  172  of top panel  179  of the inner bag, the bottom of channels of inner surface  688  of top panel  655  more or less coincide with the bottom of channels of the outer surface  172  of top panel  179 . Top panel  655  of the outer bag also has an outer surface  680 . The island-like-protuberances  686  of inner surface  688  of top panel  655  more or less forms a cup over the island-like-protuberances  176  of the outer surface  172  of top panel  179  when the inner surface  688  touches the outer surface  172 . Thus, island-like-protuberances  686  and the island-like-protuberances  176  together form pockets of spaces when the inner surface  688  touches the outer surface  172 . Similarly, the island-like-protuberances  676  of inner surface  678  of bottom panel  675  of the outer bag more or less forms a cup under the island-like-protuberances  186  of the outer surface  182  of bottom panel  189  of the inner bag when the inner surface  678  touches the outer surface  182 . Bottom panel  675  of the outer bag also has an outer surface  680 . Also the bottom of groove  184  touches the bottom of groove  674  when the inner surface  678  touches the outer surface  182 . 
     FIG. 7 ,  FIG. 8  and  FIG. 9  illustrate various patterns according to certain embodiments. In  FIG. 7  groves  704  are represented by the thick lines. The island like-protuberances  702  are represented by the white spaces. In  FIG. 8  groves  804  are represented by the thick lines. The island like-protuberances  802  are represented by the white spaces. In  FIG. 9  groves  904  are represented by the thick lines. The island like-protuberances  902  are represented by the white spaces. The patterns as shown in  FIG. 7 ,  FIG. 8  and  FIG. 9  can be used for either the inner bag and/or the outer bag. The patterns that are used for the inner bag and the outer bag will vary from implementation to implementation . The embodiments are not restricted to any particular pattern. Any arbitrary pattern can be used as long as there are raised portions interspersed among channels on at least one surface of the of the panel. The raised portion and channels can be of arbitrary shape. The flip surface of the panel can be a mirror image of the other surface of the panel. For example, there are raised ridges on the flip surface corresponding to the channels of the other surface and there are wells on the flip surface corresponding to the raised portions of the other surface. 
     FIG. 10  and  FIG. 11  illustrate inner surfaces of panels of an inner bag.  FIG. 10  shows inner surface  1022  of panel  1050 . Inner surface  1022  includes raised rings  1002 , raised ridges  1010 , wells  1006  and wells  1008 . Panel  1060  has an inner surface  1020 . There are straw-like channels on inner surface  1020 . The inner surface  1020  will overlie inner surface  1022  to form an inner bag. 
   According to certain embodiments, panel  1002  can be the inner surface of an outer bag that overlies outer surface of an inner bag where such an outer surface looks like the inner surface of panel  1060 . According to certain other embodiments, panel  1060  can be the inner surface of an outer bag that overlies outer surface of an inner bag where such an outer surface looks like the inner surface of panel  1002 . 
     FIG. 11  shows inner surface  1122  of panel  1150 . Inner surface  1122  is composed of raised rings  1102  with ring-like wells  1106  formed between the raised rings. Panel  1160  has similar raised rings  1112  with ring-like wells  1116  formed between the raised rings  1112 . The inner surface  1160  will overlie inner surface  1150  to form an inner bag. 
   According to certain embodiments, panel  1150  can be the inner surface of an outer bag that overlies outer surface of an inner bag where such an outer surface looks like the inner surface of panel  1160 . 
   The embodiments are not restricted to any one method of manufacturing the patterned composite flexible bags. One example of manufacturing flexible bags is described in application Ser. No. 10/169,485, entitled, “Method for Preparing Air Channel-Equipped Film For Use In Vacuum Package, by Kyul-Joo Lee, filed on Jun. 6, 2002, and which is hereby incorporated by reference in its entirety. 
   In the foregoing specification, embodiments of the invention have been described with reference to numerous specific details that may vary from implementation to implementation. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.