Abstract:
A package comprising at least one paper layer, the paper layers being biodegradable, and a sheet of film adherent to one of said layers, said film sheet being leak-proof, and biodegradable.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to packaging, and more particularly to improvements in packages or bags having unusual advantages as to use and disposal. 
     There is need for packaging that is easily and readily fabricated, useful, bendable in one preferred direction, and disposable in accordance with environmental standards. In particular, there is need for bags as disclosed herein having the unusual advantages in construction, functions, use and results, as will be seen. 
     SUMMARY OF THE INVENTION 
     It is a major object of the invention to provide a package that comprises: 
     a) at least one paper layer, said paper layer being biodegradable, 
     b) and a sheet of film adherent to one of said layers, said film sheet being leak-proof, and biodegradable. 
     As will be seen, the film sheet may typically consist of corn derivative from which starch has been removed, a preferred example being polylactic acid, a carbon neutral biopolymer. 
     It is another object to provide multiple of such paper layers, bonded together in superposed relation, and preferably adhesive stripes are employed and spaced apart to enhance flexibility and/or bendability of the bag wall or walls, the layers and adhesive being biodegradable. In this regard, the paper layers may consist of Kraft paper, or the like. 
     Yet another object is to provide three of such paper layers, bonded together with generally parallel extending stripes of adhesive, the lateral spacing between longitudinally extending stripes exceeding four times the widths of such stripes. As will be seen, stripes between first and second paper layers preferably extend in superposed relation to stripes between second and third paper layers, enhancing bag wall flexibility and bendability. Added objects include providing adhesive stripes adhering said film sheet to said at least one paper layer; orienting all of the adhesive stripes to extend longitudinally; and providing package folded edge portions incorporating adhesive stripes. 
     A further object is to provide a 100% organic, natural package that is 100% compostable in commercial composting environment. 
     These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: 
    
    
     
       DRAWING DESCRIPTION 
         FIG. 1  is a plan view of preferred bag or package wall portion; 
         FIG. 2  is a section taken on lines  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a perspective view of a section of bag wall; 
         FIG. 4  is an elevation view of a bag incorporating the invention; 
         FIG. 5  is a schematic view showing a bag surface being striped with adhesive; and 
         FIG. 6  is a schematic view of corn derivative film being laid down and adhesively bonded to one side of a group of paper layers. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIGS. 1 and 2 , three paper layers  10 ,  11  and  12  are shown extending in side-by-side, superposed relation to form a preferred composite  13 . Such layers typically and preferably consist of Kraft paper or the like, and which is biodegradable. A sheet  14  of biodegradable film is adhered to one side of the composite, as by provision of biodegradable adhesive  15 , as shown. The film is a compostable, clear film made from annually renewable plant resources. PLA (polylactic acid) a carbon neutral low fat corn derivative biopolymer from which starch has been removed, is manufactured under the resin trade name of Ingeo. Advantageous properties of the film include: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Scratch resistance 
                 Excellent stiffness 
               
               
                   
                 FDA compliant 
                 Good slip and dispensing 
               
               
                   
                   
                 properties 
               
               
                   
                 Dimensionally stable 
                 Excellent lay flat 
               
               
                   
                   
                 capability 
               
               
                   
                 Easily treated to higher 
                   
               
               
                   
                 dyne levels 
                   
               
               
                   
                 Excellent printability 
               
               
                   
                   
               
             
          
         
       
     
     Properties of the film include: 
     
       
         
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 Physical 
                   
                   
                   
               
               
                 Properties 
                 Units 
                 Typical Values 
                 Test Methods 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Thickness 
                 mil 
                 0.80 
                 1.00 
                 1.20 
                 1.60 
                 2.00 
                 ASTM D4321 
               
               
                   
                 gauge 
                 80 
                 100 
                 120 
                 160 
                 200 
                   
               
               
                 Yield 
                 in.2/lb 
                 27,680 
                 22,144 
                 18,453 
                 13,840 
                 11,072 
                 ASTM D4321 
               
               
                   
               
             
          
         
       
     
     The film is further characterized as sufficiently leak proof to withstand, at least temporarily, any wetness associated with pet food. 
     One film is known as PLA produced by Earth First BCL at www.earthfirstpla.com, and meets ASTM D6400 standard specifications for compostable plastic material. The adhesive  15  consists of Reynco 53-462 PLW, a water based synthetic resin adhesive, a product of the Reynolds Company, Greenville, S.C. 29611. 
     The paper layers  10 - 12  are intermittently bonded together in superposed relation, by employment of adhesive stripes  18  and  19 , which extend longitudinally in generally parallel relation, and are spaced apart laterally, for example by spacing  20  exceeding four times the width or width of the stripes. Note that the longitudinal stripes  18  between first and second layers  10  and  11  are superposed over the stripes  19  between layers  11  and  12 . This maximizes bendability or flexibility of the composite, as in a lateral direction, slippage being accommodated at unbonded interfacing  21  between laterally spaced stripes  18  and laterally spaced stripes  19 . 
       FIG. 5  shows progressive and controlled extrusion of adhesive such as at  18  via extruders  22  which are laterally spaced apart, the typical sheet  10  traveling in longitudinal direction  23 , under the extruders.  FIG. 6  shows film or film sheet  14  being unrolled or guided from a roll  27 , and laid into the surface of paper layer  12 , onto which adhesive  15  has been applied. The adhesive is preferably applied in stripes  31  that extend longitudinally superposed over stripes  18  and  19 , and are laterally spaced apart, aiding bendability and flexibility of the composite in a lateral direction. Other methods are usable. 
       FIG. 4  shows stripe zones  35  extending longitudinally on bag front and back walls  13   a  and  13   b , and stripe zones  35   a  and  35   b  extending longitudinally on bag folded edge portions  13   c  and  13   d . Such folded edge portions are adhered to front wall  13   a  by adhesive stripes, extending longitudinally. 
     All adhesive material used in the process is biodegradable, and may consist of Reynco 53-462 PLM, a water based synthetic resin adhesive, a product of the Reynolds Company, Greenville, S.C. 29611. 
     The specification for the paper of the entire example bag  13  is: 1/50 cc Paper 2/50 NK 1 layer of PLA material. Different thicknesses of paper are usable, for heavier or lighter products.