Heat-sealed multi-wall flexible container

Abstract

The invention relates to a multi-wall flexible container that includes an outer wall of a laminate of first and second sheets, and one or more heat sealed or heat sealable joints. The first sheet is made of a material that is different from that of the second sheet and the laminate is configured to form a tube with one of the sheets providing an outer surface of the container. The container also may include at least one additional wall member comprising a third sheet material.

1 . A multi-wall flexible container comprising: 
 an outer wall member comprising a laminate of first and second sheets, with the first sheet made of a material that is different from that of the second sheet and the laminate configured to form a tube with one of the sheets providing an outer surface of the container;    a first sealed joint associated with one end of the tube to assist in forming a bottom portion of the container; and    a second sealed joint associated with the laminate for forming at least one side seam of the container,    wherein one of the first or second sheets comprises paper while the other comprises a sheet material that is capable of bonding to paper and that has increased strength or moisture resistance compared to a paper sheet.    
   
   
       2 . The container of  claim 1 , wherein the first sheet comprises a polymeric film, a metal foil, or a plastic coated, fiber reinforced or metallized paper sheet, and the second sheet comprises paper.  
   
   
       3 . The container of  claim 2 , which further comprises at least one additional wall member comprising a third sheet material for providing additional structure to the container.  
   
   
       4 . The container of  claim 3 , wherein the at least one additional wall member comprises a polymeric film, a metal foil, a fabric, a netting made of the previously recited materials, a plastic coated, fiber reinforced or metallized paper sheet, or a cushioning material comprising a foam or other gas filled cellular material.  
   
   
       5 . The container of  claim 3 , wherein the additional wall member is a different material than that of the first sheet.  
   
   
       6 . The container of  claim 2 , wherein the first sheet provides the outer surface of the container and comprises an oriented polymer film while the second sheet comprises paper so that the paper may be viewed through the polymer film while the polymer film protects the paper from damage during handling of the container.  
   
   
       7 . The container of  claim 6 , which further comprises visual information comprising one or more ink images provided between the polymer film and paper sheet.  
   
   
       8 . The container of  claim 7 , wherein the polymer film is adhesively cold laminated to the paper sheet by a water-based adhesive.  
   
   
       9 . The container of  claim 8 , wherein the water-based adhesive comprises a vinyl acetate ethylene copolymer.  
   
   
       10 . The container of  claim 8 , wherein the one or more ink images are resistant to deterioration when in contact with moisture.  
   
   
       11 . The container of  claim 8 , wherein the ink images of the visual information comprise water-based inks that are applied to the paper sheet and which include a varnish coating to resist deterioration when the paper sheet is contacted by the water-based adhesive.  
   
   
       12 . The container of  claim 9 , wherein the ink images of the visual information comprise organic solvent based inks that are applied to the polymer film.  
   
   
       13 . The container of  claim 2 , wherein the paper second sheet provides the outer surface of the container while the first sheet comprises the polymer film, the metal foil, or the plastic coated or metallized paper sheet, so that the second paper sheet provides the outer surface of the container which may be readily printed while the first sheet provides a moisture resistant interior for the container.  
   
   
       14 . The container of  claim 3 , wherein the at least one additional wall member forms a liner that is positioned within the laminate and configured to form an inner tube to provide additional strength to and reinforcement of the container and for contacting a product that is placed in the container, with the first sealed joint associated with one end of both the laminate and inner tubes to assist in forming a bottom portion of the container.  
   
   
       15 . The container of  claim 14 , wherein the first sheet provides the outer surface of the container and comprises an oriented polymer film while the second sheet comprises paper, and further comprising visual information comprising one or more ink images provided between the polymer film and paper sheet, wherein the one or more ink images are resistant to deterioration when in contact with moisture so that the visual information may be viewed through the polymer film and the polymer film protects the visual information and paper from damage during handling of the container, and the liner is paper and is spot-adhered to the laminate to hold the liner material in a desired orientation with regard to the laminate.  
   
   
       16 . The container of  claim 6 , wherein the first sheet of the laminate comprises an oriented polymer film that has a surface that is energized to have increased dynes and an affinity for adhesives, and wherein the film is laminated to the paper sheet by a water-based adhesive that contacts the treated surface of the film and has its water absorbed by the paper sheet to effect lamination thereof.  
   
   
       17 . The container of  claim 16 , wherein the laminate further comprises an additional oriented polymer film that has a surface that is energized to have increased dynes and an affinity for adhesives, wherein the additional film is laminated to the paper sheet by a water-based adhesive that contacts the treated surface of the additional film and has its water absorbed by the paper sheet to effect lamination thereof and provide an inner surface of the laminate that provides moisture resistance inside the container.  
   
   
       18 . The container of  claim 17 , wherein the polymer film of the outer surface, the inner surface, or both, is polypropylene, polyethylene, or polyester.  
   
   
       19 . The container of  claim 18 , wherein the film of the outer protective layer, the inner protective layer, or each layer, is biaxially oriented.  
   
   
       20 . The container of  claim 1 , wherein the first and second sealed joints are made by a hot melt adhesive.  
   
   
       21 . The container of  claim 1 , which further comprises a hot melt adhesive positioned on an open end of the laminate tube to facilitate formation and sealing of a top portion of the container after a product is filled therein.  
   
   
       22 . In a method of making a multi-wall flexible container that includes at least two wall members, the improvement which comprises forming an outer wall member of the container of a laminate of first and second sheets, with the first sheet made of a material that is different from that of the second sheet and the laminate configured to form a tube with one of the sheets providing an outer surface of the bag, wherein one of the first or second sheets comprises paper while the other comprises a sheet material that is capable of bonding to paper and that has increased strength or moisture resistance compared to paper.  
   
   
       23 . A method of forming a multi-wall flexible container for containing a product therein, which comprises: 
 providing a laminate comprising a first sheet that will form an outer wall member of the bag, the first sheet being laminated to a second sheet of a material that is different from that of the first sheet;    folding the laminate to a tubular shape;    providing a first sealed joint on one end of the laminate and one additional wall member that assists in forming a bottom portion of the bag;    providing a second sealed joint between side portions of the laminate for forming a side seam of the bag, with the first and second joints each being provided by applying and melting a hot melt adhesive that bonds the laminate ends or portions sheets together to form the joint; and    arranging and configuring the sealed joints to enable the laminate to define an interior space that is capable of receiving a product therein;    wherein one of the first or second sheets comprises paper while the other comprises a sheet material that is capable of bonding to paper and that has increased strength or moisture resistance compared to paper.    
   
   
       24 . The method of  claim 23  which further comprises providing-at least one additional wall member comprising a third sheet material, wherein folding the laminate and at least one additional wall member are folded to a tubular shape, and the sealed joints are arranged and configured to enable the laminate and at least one additional wall member to define an interior space that is capable of receiving a product therein.  
   
   
       25 . The method of  claim 23  which further comprises placing a product, item, or article in the container, providing a strip of hot melt adhesive positioned on the laminate tube to facilitate formation and sealing of a top portion of the container, and sealing the top portion of the container after the product, item or article is placed therein to form a sealed container.  
   
   
       26 . A multi-wall flexible container produced by the method of  claim 23 .  
   
   
       27 . A sealed and filled multi-wall flexible container produced by the method of  claim 25.