Method and device for the manufacture of perforated films or foils

Abstract

A device for the manufacture of perforated films or foils comprises a means ( 5 ) for the perforation of the film or foil ( 2 ), as well as a means ( 19 ) for crimping the edges of the thusly produced holes. By crimping the edges, the holes are fixed after having been opened. Punching tools for cutting the perforation out of the film or foil are not required. Rather, the desired hole is first created as a puncture, or as a cut, and is then widened. During the crimping operation, the material bent out of the plane of the film or foil is fixed in place in such a manner that it will not close the pierced hole again.

1 . Method for the manufacture of perforated films or foils ( 2 ), whereby holes ( 25 ) are first produced in the film or foil ( 2 ), and whereby the edges ( 27 ) of the resultant holes ( 25 ) in the film or foil ( 2 ) are crimped.  
   
   
       2 . Method in accordance with  claim 1 , characterized in that the holes ( 25 ) are produced with needle-like tools ( 14 ).  
   
   
       3 . Method in accordance with  claim 1 , characterized in that the film or foil ( 2 ) is guided between two clamping elements ( 6 ,  9 ) and is clamped between said elements in order to be pierced.  
   
   
       4 . Method in accordance with  claim 1 , characterized in that, in order to produce the holes ( 25 ), pierced holes are first produced, and that said holes are subsequently widened.  
   
   
       5 . Method in accordance with  claim 1 , characterized in that, while crimping the edges ( 27 ) of the holes ( 25 ), material present on the film or foil ( 2 ) is folded and pressed against said film or foil.  
   
   
       6 . Device for the perforation of films or foils ( 2 ), comprising 
 a means ( 5 ) for producing holes in the film or foil ( 2 ), and    a means ( 19 ) for crimping the edges ( 27 ) of the produced holes ( 25 ).    
   
   
       7 . Device in accordance with  claim 6 , characterized in that the device comprises a means ( 7 ) for supporting the film or foil ( 2 ) during the piercing operation.  
   
   
       8 . Device in accordance with  claim 6 , characterized in that the means ( 5 ) for piercing the film or foil ( 2 ) is a tool ( 14 ) having a longitudinal working part ( 16 ) with a tip ( 18 ), whereby the cross-section of the working part ( 16 ) enlarges extending from said tip.  
   
   
       9 . Device in accordance with  claim 8 , characterized in that the working part ( 16 ) is configured as a needle.  
   
   
       10 . Device in accordance with  claim 8 , characterized in that the tip ( 18 ) is a punctiform tip.  
   
   
       11 . Device in accordance with  claim 8 , characterized in that the tip ( 18 ) is configured as a cutting edge.  
   
   
       12 . Device in accordance with  claim 8 , characterized in that the working part ( 16 ) has a circular cross-section.  
   
   
       13 . Device in accordance with  claim 8 , characterized in that the working part ( 16 ) has a knife-type cross-section.  
   
   
       14 . Device in accordance with  claim 8 , characterized in that working part ( 16 ) has a polygonal cross-section.  
   
   
       15 . Device in accordance with  claim 8 , characterized in that the working part ( 16 ) has a section with a constant cross-section.  
   
   
       16 . Device in accordance with  claim 8 , characterized in that the means for supporting the film or foil ( 2 ) has a support surface ( 7 ) which is provided with openings ( 11 ) that are associated with the tool ( 14 ) for producing the holes ( 25 ).  
   
   
       17 . Device in accordance with  claim 16 , characterized in that each of the openings ( 11 ) has a diameter which is greater than the diameter of the working part ( 16 ) associated with the opening ( 11 ).  
   
   
       18 . Device in accordance with  claim 6 , characterized in that the means ( 19 ) for crimping the edges ( 27 ) of the holes ( 25 ) comprises a first element ( 20 ) with a pressure surface ( 22 ) facing the underside of the film or foil ( 2 ) and comprises a second element ( 21 ) with a pressure surface ( 23 ) facing the upper side of the film or foil ( 2 ), and further comprises a drive means for moving the two elements ( 20 ,  21 ) in a controlled manner toward each other and away from each other.  
   
   
       19 . Device in accordance with  claim 6 , characterized in that the film or foil ( 2 ) is associated with a transport device ( 4 ) in order to intermittently move the film or foil through the device ( 1 ).  
   
   
       20 . Method for the manufacture of perforated films or foils ( 2 ), whereby holes ( 25 ) are first produced in the film or foil ( 2 ) by means of a tool ( 14 ) which has a longitudinal working part ( 16 ) with a tip ( 18 ), extending from which the cross-section of the working part ( 16 ) enlarges, in that the tool ( 5 ) carries out a linear back and forth movement in axial direction, the stroke width of said movement being used for the adjustment of the hole size, and whereby the edges ( 27 ) of the previously formed holes ( 25 ) of the film or foil ( 2 ) are crimped.  
   
   
       21 . Device for the perforation of films or foils ( 2 ), 
 comprising a tool ( 14 ) for piercing the film or foil ( 2 ), whereby the tool ( 5 ) for producing the holes in the film or foil ( 2 ): 
 performs a linear back and forth movement in axial direction, the stroke width of said movement being used for the adjustment of the hole size, and  
 has a longitudinal working part ( 16 ) with a tip ( 18 ), extending from which the cross-section of the working part ( 16 ) enlarges,  
   and comprising a means ( 19 ) for the subsequent crimping of the edges ( 27 ) of the produced holes ( 25 ).