Pouch or sack for packing and laminate film therefor and method for producing the pouch

Abstract

Disclosed are a pouch for containing a material therein, a laminate film for the pouch, and a method for producing the pouch. The laminate film comprises a first plastic layer and at least one second plastic layer on which said first plastic layer is laminated. The first plastic layer is partially subjected to surface roughening treatment prior to the lamination, and surface irregularities are filled with a plastic material of the second plastic layer. In a pouch having substantially rectangular shape, at least one folded portion is provided at a side edge of the pouch. The surface roughened portion is positioned at and around the folded portion and at an external surface of the pouch. In one embodiment, the folded edge is provided at one side of the pouch and a heat sealed portion is provided at the other side edge thereof. In another embodiment, folded portions are provided at both side edges of the pouch and a heat-sealed portion is provided at a rear central portion thereof.

What is claimed is: 
     
       1. A laminate film .[.for.]. pouch comprising: an external plastic layer; and.[.,.].   at least one internal plastic layer on which said external plastic layer is laminated; said external plastic layer being formed with a surface roughened portion at a .Iadd.non-heat-sealed .Iaddend.position .[.corresponding to a folded portion of a resultant.]. .Iadd.crossing a fold line of the .Iaddend.pouch.   
     
     
       2. The laminate film .Iadd.pouch .Iaddend.as claimed in claim 1, wherein said external plastic layer comprises .[.polypropyrene.]. .Iadd.polypropylene .Iaddend.film. 
     
     
       3. The laminate film .Iadd.pouch .Iaddend.as claimed in claim 2, wherein said .[.polypropyrene.]. .Iadd.polypropylene .Iaddend.film is a single axial stretching film. 
     
     
       4. The laminate film .Iadd.pouch .Iaddend.as claimed in claim 1, wherein said external plastic layer comprises polyester film. 
     
     
       5. The laminate film .Iadd.pouch .Iaddend.as claimed in claim 1, wherein said internal plastic layer comprises polyethylene film. 
     
     
       6. The laminate film .Iadd.pouch .Iaddend.as claimed in claim 4, further comprising an aluminum foil laminated with said internal plastic layer, and a plastic film laminated with said aluminum foil. 
     
     
       7. The laminate film .Iadd.pouch .Iaddend.as claimed in claim 1, wherein said surface roughened portion .[.has.]. .Iadd.forms a .Iaddend.continuous meandered .[.arrangement, said meandered portion.]. .Iadd.line .Iaddend.having a small width, and .Iadd.a large .Iaddend.resultant .[.surface roughened portion having a wide.]. .Iadd.meandered .Iaddend.width extending .[.over said folded portion.]. .Iadd.across said fold line.Iaddend.. 
     
     
       8. The laminate film .Iadd.pouch .Iaddend.as claimed in claim 1, wherein said surface roughened portion is formed with a plurality of circular recesses arranged in groups of rows, said groups being directed in parallel with each other and extending obliquely with respect to .[.a folded line of.]. said .[.folded portion.]. .Iadd.fold line.Iaddend.. 
     
     
       9. The laminate film .Iadd.pouch .Iaddend.as claimed in claim 1, wherein said surface roughened portion is formed with .[.a.]. surface .[.irregularlities.]. .Iadd.irregularities .Iaddend.into which a material of said internal plastic layer is filled. 
     
     
       10. A pouch comprising: a laminated film defining a rectangular pouch body; said laminated film comprising an external plastic layer and an internal plastic layer, said laminated film being formed with at least one folded portion .Iadd.containing a fold line.Iaddend., and a heat-sealed portion connecting free ends of said laminated film, .Iadd.a non-heat-sealed area of .Iaddend.said folded portion being formed with a surface roughened portion which .Iadd.crosses said fold line and .Iaddend.is formed at the external side of said pouch. 
     
     
       11. The pouch as claimed in claim 10, wherein said folded portion .[.is positioned at.]. .Iadd.form .Iaddend.one side edge portion of said pouch, and said heat-sealed portion .[.is positioned at the other.]. .Iadd.forms another .Iaddend.side edge portion thereof. 
     
     
       12. The pouch as claimed in claim 10, wherein two folded portions .[.are provided at both.]. .Iadd.form two .Iaddend.side edge portions of said pouch, said heat-sealed portion projecting outwardly at a rear portion of said pouch. 
     
     
       13. The pouch as claimed in claim 12, further comprising a second surface roughened portion at a folded portion of said heat-sealed portion. 
     
     
       14. The pouch as claimed in claim 10, wherein each of .Iadd.two .Iaddend.side edge portions of said pouch comprises three folding lines to provide two ridge portions and one valley portion positioned between said two ridge portions, one of the side edge portions being formed with said surface roughened portions at said ridge portions, and the other side edge portion being formed with said surface roughened portion at said valley portion. 
     
     
       15. The pouch as claimed in claim 14, wherein said heat-sealed portion projects outwardly from a rear portion of said pouch, and a second surface roughened portion is provided at and around a folded line of said heat-sealed portion. 
     
     
       16. The pouch as claimed in claim 10, wherein said external plastic layer comprises .[.polypropyrene.]. .Iadd.polypropylene .Iaddend.film. 
     
     
       17. The pouch as claimed in claim 16, wherein said .[.polypropyrene.]. .Iadd.polypropylene .Iaddend.film is a single axial stretching film. 
     
     
       18. The pouch as claimed in claim 10, wherein said external plastic layer comprises polyester film. 
     
     
       19. The pouch as claimed in claim 10, wherein said internal plastic layer comprises polyester film. 
     
     
       20. The pouch as claimed in claim 18, further comprising an aluminum foil laminated with said internal plastic layer, and a plastic film laminated with said aluminum foil. 
     
     
       21. The pouch as claimed in claim 10, wherein said surface roughened portion .[.has.]. .Iadd.forms a .Iaddend.continuous meandered .[.arrangement, said meandered portion.]. .Iadd.line .Iaddend.having a small width, and .Iadd.a large .Iaddend.resultant .[.surface roughened portion having a wide.]. .Iadd.meandered .Iaddend.width extending .[.over said folded portion.]. .Iadd.across said fold line .Iaddend.. 
     
     
       22. The pouch as claimed in claim 10, wherein said surface roughened portion is formed with a plurality of circular recesses arranged in groups of rows, said groups being directed in parallel with each other and extending obliquely with respect to .[.a folded line of.]. said .[.folded portion.]. .Iadd.fold line.Iaddend.. 
     
     
       23. The pouch as claimed in claim 10, wherein said surface roughened portion is formed with .[.a.]. surface .[.irregularlities.]. .Iadd.irregularities .Iaddend.into which a material of said internal plastic layer is filled. 
     
     
       24. A method for producing a pouch comprising the steps of: preparing a rectangular first plastic film web and at least one rectangular second plastic film web;   roughening partial surface portions of .[.a.]. one surface of said first plastic film web, said partial portions .[.corresponding to folded portions.]. .Iadd.crossing a non-heat-sealed portion of said web corresponding to at least one fold line .Iaddend.of said pouch;   laminating together said first and second plastic film webs to provide a composite film;   cutting said composite film into rectangular segments;   folding said rectangular .[.segment,.]. .Iadd.segments along said fold line; .Iaddend.and   heat-sealing free ends of said rectangular .[.segment.]. .Iadd.segments.Iaddend..   
     
     
       25. The method as claimed in claim 24, wherein .[.said.]. .Iadd.the .Iaddend.roughening step is performed by pressing a rigid roughening member onto said one surface of said first plastic film web. 
     
     
       26. The method as claimed in claim 24, wherein said roughening step is performed by applying one of laser beam, corona discharge, plasma discharge and ultrasonic wave onto parts of said first plastic film web. 
     
     
       27. The method as claimed in claim 24, further comprising the step of printing the other surface of .[.said.]. .Iadd.the .Iaddend.first plastic film web prior to said roughening step. .Iadd. 
     
     
       28.  The laminate film pouch as claimed in claim 1, wherein said surface roughened portion is formed at a portion of the pouch between two opposite heat sealed edges of the pouch. .Iaddend. .Iadd.29. The pouch as claimed in claim 10, wherein said surface roughened portion is formed at a portion of the pouch between two opposite heat sealed edges of the pouch. .Iadd.30. The method as claimed in claim 24, wherein said partial surface portions are roughened at a portion of said web corresponding to a portion of the pouch between said heat sealed free ends of said rectangular segments. .Iaddend. .Iadd.31. A pouch comprising: a pouch body formed of a laminate sheet including at least two layers of material, the laminate sheet comprising:   a first layer formed of a plastic material and being provided with a tear facilitating surface roughened portion comprising surface irregularities;   a second layer laminated to the first plastic layer; and   filling material at least partially filling the surface irregularities;   wherein the tear facilitating surface roughened portion forms a guide line extending across a non-heat-sealed portion of the pouch body for tearing   
     
     
        the pouch body along the guide line. .Iaddend. .Iadd.32.  The pouch as claimed in claim 31, wherein said first layer is an exterior layer of said pouch. .Iaddend. .Iadd.33. The pouch as claimed in claim 31, wherein the filling material comprises a resin. .Iaddend. .Iadd.34. The pouch as claimed in claim 31, wherein the second layer is formed of a plastic material and wherein the filling material is the same as the plastic material of the second layer. .Iaddend. .Iadd.35. The pouch as claimed in claim 34, wherein the filling material is material flowed from the second layer into the surface irregularities during lamination of the first and second layers. .Iaddend. .Iadd.36. The pouch as claimed in claim 31, wherein said surface irregularities comprise a plurality of scores or 
     
     
        scratches. .Iaddend. .Iadd.37.  A pouch comprising: a pouch body formed of a laminate sheet including at least two layers of material, the laminate sheet comprising:   a first layer formed of a plastic material and being provided with a tear facilitating surface roughened portion comprising surface irregularities;   a second layer laminated to the first plastic layer; and   filling material at least partially filling the surface irregularities;   wherein said surface roughened portion has a continuous meandered arrangement extending across a non-heat-sealed portion of the pouch body and providing a resultant surface roughened portion of relatively large   
     
     
        width. .Iaddend. .Iadd.38.  A pouch comprising: a pouch body formed of a laminate sheet including at least two layers of material, the laminate sheet comprising:   a first layer formed of a plastic material and being provided with a tear facilitating surface roughened portion comprising surface irregularities;   a second layer laminated to the first plastic layer; and   filling material at least partially filling the surface irregularities;   wherein said surface roughened portion is formed of a plurality of circular rough surface portions arranged in a plurality of rows directed parallel to each other and obliquely to an edge of the pouch and extending across a   
     
     
        non-heat-sealed portion of the pouch body. .Iadd.39.  A sheet product comprising at least one plastic sheet having a tear facilitating surface roughened portion, said surface roughened portion comprising a group of densely formed and randomly oriented surface irregularities, said group being in the form of a continuous meandered arrangement providing a resultant surface roughened portion of relatively large width. .Iaddend. 
     
     
        .Iadd.40.  The sheet product claimed in claim 39, wherein said sheet product is a sealed pouch. .Iaddend. .Iadd.41. A sheet producing comprising at least one plastic sheet having a tear facilitating surface roughened portion, said surface roughened portion being formed of a plurality of circular rough surface portions, each containing densely formed and randomly oriented surface irregularities, arranged in a plurality of rows directed parallel to each other and obliquely to an edge of the product. .Iaddend. .Iadd.42. A sheet product as claimed in claim 41, wherein said sheet product is a sealed pouch. .Iaddend.