Package with strip closure system, method for making same

Abstract

The subject of the invention is a package comprising at least two sheets ( 2, 3 ) and two flexible films ( 10 a, 10 b ) placed between them and welded to the sheets ( 2, 3 ) by the welds ( 11 a, 11 b ) respectively, and welded together and to the sheets ( 2, 3 ) by the welds ( 12 a, 12 b ), at least one of the two films being folded over the other at that end of the films on the opposite side to the welds ( 11 a, 11 b ). The subject of the invention is also a method for manufacturing such a package. The invention makes it possible to obtain a package of simplified structure and simplified manufacture.

1 . A package comprising at least two sheets ( 2 ,  3 ) and two flexible films ( 10   a ,  10   b ) placed between them and welded to the sheets ( 2 ,  3 ) by the welds ( 11   a ,  11   b ) respectively, and welded together and to the sheets ( 2 ,  3 ) by the welds ( 12   a ,  12   b ), at least one of the two films being folded over the other at that end of the films on the opposite side to the welds ( 11   a ,  11   b ).  
     
     
         2 . The package according to  claim 1 , the two films being folded over on themselves at that end of the films on the opposite side to the welds ( 11   a ,  11   b ).  
     
     
         3 . The package comprising at least two sheets ( 2 ,  3 ) and two flexible films ( 10   a ,  10   b ) placed between and welded to the sheets ( 2 ,  3 ) by the welds ( 11   a ,  11   b ) respectively, and welded together by the welds ( 12 ′ a ,  12 ′ b ) and to the sheets ( 2 ,  3 ) by the welds ( 12   a ,  12   b ), the welds ( 12 ′ a ,  12 ′ b ) being between the welds ( 12   a ,  12   b ), at least one of the two films being folded over the other at that end of the films on the opposite side to the welds ( 11   a ,  11   b ).  
     
     
         4 . The package according to  claim 3 , the two films being folded over on themselves at that end of the films on the opposite side to the welds ( 11   a ,  11   b ).  
     
     
         5 . The package comprising at least two sheets ( 2 ,  3 ), a flexible film ( 16 ) placed between them and folded over on itself and welded to the sheets ( 2 ,  3 ) by the welds ( 17   a ,  17   b ) respectively and welded to itself and to the sheets ( 2 ,  3 ) by the welds ( 18   a ,  18   b ).  
     
     
         6 . The package according to any one of  claims 1  to  4 , in which the fold formed by the film(s) can be unfolded by inserting a straw between the films ( 10   a ,  10   b ).  
     
     
         7 . The package according to any one of  claims 1  to  5 , in which the fold formed by the film(s) cannot be unfolded by inserting a straw.  
     
     
         8 . The package according to any one of  claims 1  to  7 , having an additional weld ( 15 ) between the sheets ( 2 ,  3 ).  
     
     
         9 . The package according to any one of  claims 1  to  8 , in which the flexible film is made of PE, EVA, PP, OPP, PET or PA.  
     
     
         10 . The package according to any one of  claims 1  to  9 , in which the sheets ( 2 ,  3 ) are semi-rigid.  
     
     
         11 . The package according to any one of  claims 1  to  10 , in which the sheets ( 2 ,  3 ) and the flexible film ( 10   a ,  10   b ;  16 ) have the following characteristics, where H is the thickness in mm and E is the equivalent modulus of the film in N.mm −2 .  
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                     
                 
                     
                   sheet (2, 3): 
                   H 3 E = 0.1 to 50 N · mm; 
                 
                     
                   film (10a, 10b; 16): 
                   H 3 E = 0.5 × 10 −3  to 5 N · mm; 
                 
                     
                   with preferably: 
                 
                     
                   sheet (2, 3): 
                   H 3 E = 0.5 to 25 N · mm; 
                 
                     
                   film (10a, 10b; 16): 
                   H 3 E = 0.05 to 1 N · mm; 
                 
                 
                 
               
                     
                   with, in both cases, the relationship: 
                 
                 
                 
                 
               
                     
                   film (10a, 10b; 16) 
                   H 3 E < sheet (2, 3) H 3 E. 
                 
                     
                     
                 
                     
                     
                 
             
                
                
               
               
                
                
                
                
                
               
            
             
                
               
            
             
                
                
                
               
            
           
         
       
     
     
         12 . The package according to any one of  claims 1  to  11 , in the form of a Doypack or three-weld bag.  
     
     
         13 . A method for manufacturing a package according to any one of  claims 1  to  4  and  6  to  12 , comprising the following steps: 
 insertion of a screen-film ( 7 ) between the films ( 10   a ,  10   b );  
 welding of the films ( 10   a ,  10   b ) to the sheets ( 2 ,  3 ) along the welds ( 11   a ,  11   b ) respectively;  
 extraction of the screen-film ( 7 );  
 optionally, welding of the films ( 10   a ,  10   b ) together along the welds ( 12 ′ a ,  12 ′ b ); and  
 welding of the films ( 10   a ,  10   b ) and the sheets ( 2 ,  3 ) together along the welds ( 12   a ,  12   b ).  
 
     
     
         14 . The method for manufacturing a package according to  claim 5 , comprising the following steps: 
 insertion of a screen-film ( 7 ) in the fold formed by the film ( 16 );    welding of the film ( 16 ) to the sheets ( 2 ,  3 ) along the welds ( 17   a ,  17   b ) respectively;    extraction of the screen-film ( 7 ); and    welding of the film ( 16 ) and the sheets ( 2 ,  3 ) together along the welds ( 18   a ,  18   b ).    
     
     
         15 . The method according to either of claims  13  and  14 , in which the screen-film ( 7 ) is made of PTFE or of Teflon®-coated fabric.