Internally scored film, package and methods of making the same

Abstract

The presently preferred embodiments relate to film structures that are exposed to focused energy to provide a score line on an internal layer of the film structure, or on both an internal layer of a film structure and an outer layer of the film structure. In addition, the present invention relates to a package that may be torn along the score line. More specifically, the package may have a score line provided on an internal layer of barrier material, such as ethylene vinyl alcohol copolymer, polyvinylidene chloride copolymer, nylon, or any other laser scorable barrier material. The score line in an internal layer and/or in the surface of the film may allow the package to be opened using tearing forces, thereby exposing a product within the package and allowing a user of the package to gain access to product that may be contained therein.

We claim:  
     
         1 . A film structure comprising: 
 a plurality of layers wherein a first layer disposed as an internal layer within the film structure comprises a polymeric material wherein the polymeric material is scorable by a focused energy source;    a score line disposed within the first internal layer by the focused energy source; and    a second layer of the film structure wherein the second layer is disposed between the focused energy source and the first layer when the score line is applied to the first internal layer wherein said second layer is not scored by said focused energy source.    
     
     
         2 . The film structure of  claim 1  wherein said first layer is a barrier material.  
     
     
         3 . The film structure of  claim 1  wherein said first layer comprises a polymeric material selected from the group consisting of ethylene vinyl alcohol copolymer, polyvinylidene copolymer and nylon.  
     
     
         4 . The film structure of  claim 1  wherein said score line is provided in the first layer in both the transverse and machine directions of said film structure.  
     
     
         5 . The film structure of  claim 1  wherein said score line is a straight line.  
     
     
         6 . The film structure of  claim 1  further comprising: 
 an outer layer comprising a polymeric material that is scorable by a focused energy source.  
 
     
     
         7 . The film structure of  claim 6  wherein said score line is disposed in both first layer and the outer layer.  
     
     
         8 . The film structure of  claim 6  wherein said outer layer comprises a polymeric material selected from the group consisting of polyethylene terephthalate and biaxially oriented nylon.  
     
     
         9 . The film structure of  claim 1  further comprising: 
 a third layer disposed internally within the film structure comprising a polymeric material that is scorable by the focused energy source; and  
 a score line in said third layer.  
 
     
     
         10 . The film structure of  claim 9  further comprising: 
 an outer layer comprising a polymeric material that is scorable by the focused energy source; and  
 a score line in said outer layer.  
 
     
     
         11 . The film structure of  claim 1  wherein the focused energy source is a laser beam.  
     
     
         12 . The film structure of  claim 7  wherein said second layer is disposed between the first layer and the outer layer.  
     
     
         13 . The film structure of  claim 10  wherein said second layer is disposed between the first layer and the outer layer.  
     
     
         14 . The film structure of  claim 10  wherein said second layer is disposed between the third layer and the outer layer.  
     
     
         15 . A package for a product comprising: 
 a first film structure comprising a plurality of layers wherein a first layer disposed internally within the film structure comprises a polymeric material wherein said polymeric material is scorable by a focused energy source and further wherein said film structure comprises a score line disposed within said first layer by the focused energy source and further wherein the film structure comprises a second layer that is disposed between the first layer and the focused energy source when the score line is applied to said first layer wherein said second layer is not scored by the focused energy source.    
     
     
         16 . The package of  claim 15  wherein said first layer is a barrier material.  
     
     
         17 . The package of  claim 15  wherein said first layer comprises a polymeric material selected from the group consisting of ethylene vinyl alcohol copolymer, polyvinylidene copolymer and nylon.  
     
     
         18 . The package of  claim 15  wherein said score line is provided in the first layer in both the transverse and machine directions of said film structure.  
     
     
         19 . The package of  claim 15  wherein said score line is a straight line.  
     
     
         20 . The package of  claim 15  wherein said first film structure further comprises an outer layer comprising a polymeric material that is scorable by the focused energy source.  
     
     
         21 . The package of  claim 20  wherein said score line is disposed in both the first layer and the outer layer.  
     
     
         22 . The package of  claim 20  wherein the outer layer comprises a polymeric material selected from the group consisting of polyethylene terephthalate and biaxially oriented nylon.  
     
     
         23 . The package of  claim 15  wherein the film structure further comprises a third layer disposed internally within the film structure comprising a polymeric material that is scorable by a focused energy source and a score line in said third layer.  
     
     
         24 . The package of  claim 23  wherein said film structure further comprises an outer layer comprising a polymeric material that is scorable by a focused energy source and a score line in said outer layer.  
     
     
         25 . The package of  claim 15  wherein said focused energy source is a laser beam.  
     
     
         26 . The package of  claim 21  wherein said second layer is disposed between the first layer and the outer layer.  
     
     
         27 . The package of  claim 24  wherein said second layer is disposed between the first layer and the outer layer.  
     
     
         28 . The package of  claim 24  wherein said second layer is disposed between the third layer and the outer layer.  
     
     
         29 . The package of  claim 15  further comprising: 
 a second film structure heat sealed to said first film structure thereby forming a cavity within the package for a product.  
 
     
     
         30 . The package of  claim 15  wherein said first film structure forms a first package wall and further wherein a second package wall is heat sealed to said first film structure to form a cavity within the package for a product.  
     
     
         31 . A method of making a laser-scored film structure comprising the steps of: 
 providing a multilayer film structure comprising a plurality of layers wherein a first layer comprises a polymeric material wherein the polymeric material is scorable by a focused energy source;    exposing said film structure to the focused energy source;    scoring said first layer with said focused energy source;    providing a second layer disposed between the first layer and the focused energy source when the focused energy source scores the first layer; and    not scoring said second layer when said first layer is scored.    
     
     
         32 . The method of  claim 31  wherein said first layer is a barrier material.  
     
     
         33 . The method of  claim 31  wherein the first layer is a polymeric material selected from the group consisting of ethylene vinyl alcohol copolymer, polyvinylidene chloride copolymer and nylon.  
     
     
         34 . The method of  claim 31  further comprising the step of: 
 coextruding said plurality of layers to form said film structure.  
 
     
     
         35 . The method of  claim 31  further comprising the step of: 
 laminating said plurality of film layers to form said film structure.  
 
     
     
         36 . The method of  claim 31  further comprising the step of: 
 scoring said first layer in both the machine and transverse directions of said film structure.  
 
     
     
         37 . The method of  claim 31  further comprising the step of: 
 providing an outer layer of said film structure wherein said outer layer comprises a material scorable with the focused energy source; and  
 scoring said outer layer with the focused energy source when the first internal layer is scored.  
 
     
     
         38 . The method of  claim 31  further comprising: 
 providing a third layer disposed internally within said film structure wherein said third layer comprises a polymeric material that is scorable by the focused energy source; and  
 scoring said third layer with the focused energy source.  
 
     
     
         39 . The method of  claim 37  wherein said second layer is disposed between said first layer and said outer layer.  
     
     
         40 . The method of  claim 38  wherein said second layer is disposed between said third layer and said outer layer.  
     
     
         41 . The method of  claim 31  wherein said focused energy source comprises a laser beam.  
     
     
         42 . A film structure comprising: 
 a plurality of layers wherein at least one of the plurality of layers has a score line disposed therein, wherein the film structure has a tensile strength across the score line of less than about 6.5 lb/in.    
     
     
         43 . The film structure of  claim 42  wherein the tensile value of the film structure has a tensile strength across the score line of less than about 4 lb/in.  
     
     
         44 . The film structure of  claim 42  further comprising: 
 an internal layer wherein the score line is disposed in the internal layer.  
 
     
     
         45 . The film structure of  claim 42  further comprising: 
 a first internal layer; and  
 an outer layer, wherein the score line is disposed in both the internal layer and the outer layer.  
 
     
     
         46 . The film structure of  claim 45  further comprising: 
 a second internal layer disposed between the first internal layer and the outer layer wherein said score line is not disposed within the second internal layer.  
 
     
     
         47 . The film structure of  claim 42  wherein said score line is disposed in said film structure via a focused energy source.  
     
     
         48 . The film structure of  claim 47  wherein said focused energy source is a focused laser beam.  
     
     
         49 . The film structure of  claim 42  wherein said film structure is between about 2 mils and about 10 mils thick.  
     
     
         50 . The film structure of  claim 42  wherein said film structure is between about 4 mils and about 8 mils thick.