Multi-layer film for forming a vacuum packaging bag and method of manufacture

Abstract

A vacuum packaging film with an improved embossed pattern suitable for evacuation of gas from a vacuum packaging bag made of the film. The embossed pattern includes a plurality of roughly parallel sequences of substantially collinear ridges. The ridges of a first sequence are offset with respect to the ridges of an adjacent second sequence.

1 . A multi-layer film suitable for use in forming a vacuum packaging bag, said multi-layer film comprising: 
 a first layer made of a first material; and    a second layer made of a second material that is formed onto said first layer, said second layer having a pattern that is operable to form channels suitable for evacuation of gas from a vacuum packaging bag made of said film, said pattern including a plurality of roughly parallel sequences of substantially collinear ridges, wherein ridges of a first sequence of said parallel sequences of substantially collinear ridges are offset with respect to an adjacent second sequence of said parallel sequences of substantially collinear ridges.    
     
     
         2 . The film of  claim 1 , wherein said first material is a gas-impermeable material, and wherein said first layer is a gas-impermeable layer.  
     
     
         3 . The film of  claim 1 , wherein said pattern is embossed onto said first layer as well as said second layer.  
     
     
         4 . The film of  claim 1 , wherein said second material is a heat-sealable resin, and wherein said second layer is a heat-sealable resin layer.  
     
     
         5 . The film of  claim 4 , wherein said heat-sealable resin is a polyethylene resin.  
     
     
         6 . The film of  claim 1 , further comprising a third material in between said first material and said second material, said third material forming a bonding layer between said first and second layers.  
     
     
         7 . The film of  claim 1 , further comprising a fourth material and a fifth material, said fourth material forming a bonding layer between said first layer and a fifth layer made of said fifth material, wherein said fifth layer is a structural layer for providing structural strength to said film.  
     
     
         8 . The film of  claim 1 , wherein said substantially collinear ridges have a striped pattern.  
     
     
         9 . The film of  claim 1 , wherein said substantially collinear ridges have a zigzag pattern.  
     
     
         10 . The film of  claim 1 , wherein said substantially collinear ridges have a wave pattern.  
     
     
         11 . The film of  claim 1 , wherein said substantially collinear ridges have an uneven pattern.  
     
     
         12 . A method of manufacturing a multi-layer film for use in vacuum packaging applications, said multi-layer film having a pattern that operates to form channels suitable for evacuation of gas when said multi-layer film is used in the creation of a vacuum packaging bag, said method comprising the acts of: 
 heat-extruding a first material onto a roller; and    heat-extruding a second material onto said roller such that said first and second extruded materials bond and form a film of said first material with a plurality of roughly parallel sequences of substantially collinear ridges of said second material forming a pattern on said film, said pattern operable to form channels suitable for evacuation of gas from a vacuum packaging bag made from said film.    
     
     
         13 . The method of  claim 12 , wherein said first material is a gas-impermeable material, said method further comprising forming a gas-impermeable layer as a first layer of said film.  
     
     
         14 . The method of  claim 14 , further comprising the act of heat-extruding a third material in between said first and second material, wherein said third material forms a bonding layer between a first layer made of said first material and a second layer made of said second material.  
     
     
         15 . The method of  claim 12 , further comprising the act of heat-extruding a fourth material and a fifth material to respectively form a bonding layer and a structural layer, wherein said bonding layer bonds said structural layer to a first layer made of said first material, and wherein said structural layer provides structural strength to said film.  
     
     
         16 . The method of  claim 12 , further comprising the act of controlling a temperature of said roller in order to properly effectuate cooling and formation of said first and second layers.  
     
     
         17 . The method of  claim 12 , wherein the act of applying a pattern to said first and second layers is accomplished by providing said pattern on the circumferential surface of said roller.  
     
     
         18 . The method of  claim 12 , wherein the act of applying a pattern to said first and second layers is accomplished by using an air knife to shape said first and second materials subsequent to extrusion.  
     
     
         19 . The method of  claim 19 , wherein said air-knife includes an inverse vacuum, further comprising imparting said pattern on said first and second materials using said inverse vacuum.  
     
     
         20 . A vacuum packaging bag for holding food or other product, said vacuum packaging bag comprising: 
 a first sheet formed of a multi-layer plastic film, said multi-layer plastic film including: 
 a first layer made of a first material; and  
 a second layer made of a second material that is laminated onto said first layer, said second layer having an embossed pattern that is operable to form channels suitable for evacuation of gas from a vacuum packaging bag made of said film, said embossed pattern including a plurality of roughly parallel sequences of substantially collinear ridges, wherein ridges of a first sequence of said parallel sequences of substantially collinear ridges are offset with respect to an adjacent second sequence of said parallel sequences of substantially collinear ridges;  
   a second sheet formed of said multi-layer plastic film, said second sheet having a footprint substantially similar to said first sheet, wherein said first and second sheets are arranged with respective second layers facing one another, said first and second sheets sealed on opposing lateral sides and at an end side, whereby said first and second sheets form a vacuum packaging bag having an opening for insertion of food or other product, said vacuum packaging bag sealable at said opening.