Composite container liner with self-supporting sealant web

Abstract

There is provided a liner for a container that provides a gas and moisture barrier. The liner includes a first sealant web of polyethylene that defines a self-supporting layer of the liner. An adhesive layer is applied to an outer surface of the first sealant web, and a metal foil layer is adhered to the adhesive layer. A second sealant layer is attached to the metal foil layer. The second sealant layer may be heat-sealed to the first sealant web so that when the liner is adhered to the inside surface of a container, the liner may be sealed to itself with a lap seal. The first sealant web defines a self-supporting layer because it provides structural support to the liner. Accordingly, the first sealant web advantageously serves as a carrier web for the liner while the liner is being manufactured.

1 . A liner for providing a gas and moisture barrier for a container, the liner comprising: 
 a first sealant web comprising polyethylene and defining a self-supporting layer of the liner, wherein the first sealant web defines an inner surface and an outer surface opposed thereto;    a metal foil layer defining an inner surface and an outer surface, wherein the inner surface of the metal foil layer is adhered to the outer surface of the first sealant web; and    a second sealant layer comprising a polymer and defining an inner surface and an outer surface opposed thereto, wherein the inner surface of the second sealant layer is attached to the outer surface of the metal foil layer, the second sealant layer being heat-sealable to the first sealant web.    
   
   
       2 . A liner according to  claim 1 , further comprising an adhesive layer adhering the inner surface of the metal foil layer to the outer surface of the first sealant web.  
   
   
       3 . A liner according to  claim 1  wherein the first sealant web comprises a coextruded web of ionomer and HDPE.  
   
   
       4 . A liner according to  claim 3  wherein the ionomer of the first sealant web comprises an ethylene acrylic acid ionomer.  
   
   
       5 . A liner according to  claim 1  wherein the first sealant web comprises a coextruded web of HDPE and LDPE.  
   
   
       6 . A liner according to  claim 1  wherein the second sealant layer comprises an ionomer.  
   
   
       7 . A liner according to  claim 6  wherein the second sealant layer comprises an ethylene acrylic acid ionomer.  
   
   
       8 . A liner according to  claim 1  wherein the metal foil layer defines a thickness of less than 0.001 inch.  
   
   
       9 . A liner according to  claim 1  wherein the metal foil layer defines a thickness of less than 0.0005 inch.  
   
   
       10 . A container that provides a gas and moisture barrier for a product, the container comprising: 
 at least one body ply formed of fibrous paperboard wrapped to form a wall of the container, wherein the wall of the container defines an inner surface; and    a liner adhered to the inner surface of the wall, the liner defining an overlap joint between opposite edges of the liner, and comprising: 
 a first sealant web comprising polyethylene and defining a self-supporting layer of the liner, wherein the first sealant web defines an inner surface and an outer surface opposed thereto;  
 a metal foil layer defining an inner surface and an outer surface, wherein the inner surface of the metal foil layer is adhered to the outer surface of the first sealant web; and  
 a second sealant layer comprising a polymer and defining an inner surface and an outer surface opposed thereto, wherein the inner surface of the second sealant layer is attached to the outer surface of the metal foil layer, the second sealant layer being heat-sealed to the first sealant web at the overlap joint.  
   
   
   
       11 . A container according to  claim 10  wherein the body ply forms a tubular container body.  
   
   
       12 . A container according to  claim 10 , further comprising a membrane lid sealed to one end of the wall of the container.  
   
   
       13 . A container according to  claim 10  wherein the liner further comprises an adhesive layer adhering the inner surface of the metal foil layer to the outer surface of the first sealant web.  
   
   
       14 . A container according to  claim 10  wherein the first sealant web comprises a coextruded web of ionomer and HDPE.  
   
   
       15 . A container according to  claim 14  wherein the ionomer of the first sealant web comprises an ethylene acrylic acid ionomer.  
   
   
       16 . A container according to  claim 10  wherein the first sealant web comprises a coextruded web of HDPE and LDPE.  
   
   
       17 . A container according to  claim 10  wherein the second sealant layer comprises an ionomer.  
   
   
       18 . A container according to  claim 17  wherein the second sealant layer comprises an ethylene acrylic acid ionomer.  
   
   
       19 . A container according to  claim 10  wherein the metal foil layer defines a thickness of less than 0.001 inch.  
   
   
       20 . A container according to  claim 10  wherein the metal foil layer defines a thickness of less than 0.0005 inch.  
   
   
       21 . A method of manufacturing a liner for a container, comprising the steps of: 
 advancing a first sealant web from a roll of the first sealant web to a laminating station, wherein the first sealant web comprises polyethylene and serves as a carrier web;    advancing a metal foil layer to the laminating station and adhering an inner surface of the metal foil layer to the first sealant web;    attaching a second sealant layer comprising a polymer to an outer surface of the metal foil layer; and    advancing the liner to a collection roll.    
   
   
       22 . A method according to  claim 21  wherein the metal foil layer is adhesive-laminated to the first sealant web.  
   
   
       23 . A method according to  claim 21  wherein the metal foil layer is extrusion-laminated to the first sealant web.  
   
   
       24 . A method according to  claim 21  wherein attaching the second sealant layer comprises extrusion-coating the second sealant layer onto the outer surface of the metal foil layer.  
   
   
       25 . A method according to  claim 21  wherein advancing the liner to the collection roll comprises advancing the liner around a chill roll prior to advancing the liner to the collection roll.