Method for Producing Identification Marks on Paper or Board and a Marked Material Made with the Method

Abstract

The invention comprises a method for producing identification marks ( 5 ) on layer-structured paper or board ( 7 ) to be manufactured in a continuous web and the marked papers and boards obtained with this method. With this method, the marks ( 5 ) are made with a laser beam on a moving web form fiber layer ( 1 ), on which a second layer of material ( 6 ) is subsequently overlaid in such a way that the marks remain inside the layer-structure of the moving web. The second material layer ( 6 ) may comprise a second fiber layer or, for example, a polymer coating. The laser marking could take place, for example, by burning the surface of the fiber layer ( 1 ) or by engraving it. Inside the layer structure, the marks ( 5 ) are protected, but detectable with a detector to ensure the authenticity of the material. The marked paper or board is suitable for product packages to be protected against product forgeries.

1 . A method for producing identification marks ( 5 ) in a layer-structured paper or board ( 7 ) to be manufactured as a continuous web, characterized in that the marks ( 5 ) are made with a laser beam ( 4 ) on a moving web form fiber layer ( 1 ), on which a second layer of material ( 6 ) is overlaid in such a way that the marks remain inside the layer structure ( 7 ) of the moving web. 
   
   
       2 . A method according to  claim 1 , characterized in that the marks ( 5 ) are made by burning the surface of the fiber layer ( 1 ). 
   
   
       3 . A method according to  claim 1 , characterized in that the marks are made by engraving hollows ( 5 ′) on the fiber layer ( 1 ). 
   
   
       4 . A method according to  claim 1 , characterized in that the fiber layer ( 1 ) contains mixing agent that is reacted or vaporized with a laser beam ( 4 ). 
   
   
       5 . A method according to  claim 1 , characterized in that after the marking phase, the moving fiber layer ( 1 ) is laid against another moving, web form fiber layer ( 6 ). 
   
   
       6 . A method according to  claim 5 , characterized in that the marking takes place with a paper or board machine as the fiber layer ( 1 ) contains moisture originating from pulp, in which case the web ( 7 ) is dried after the joining of the layers ( 1 ,  6 ). 
   
   
       7 . A method according to  claim 6 , characterized in that the materials of the fiber layers ( 1 ,  6 ) to be joined differ from one another. 
   
   
       8 . A method according to  claim 7 , characterized in that one fiber layer to be joined is of chemical pulp and the other of mechanical or chemical/mechanical pulp. 
   
   
       9 . A method according to  claim 7 , characterized in that one of the fiber layers to be joined is of unbleached pulp and the other of bleached pulp. 
   
   
       10 . A method according to  claim 1 , characterized in that the marked web form fiber layer ( 1 ) is applied with a coating layer, covering the marks ( 5 ). 
   
   
       11 . Layer-structured paper or board ( 7 ) containing identification marks that can be manufactured with a method according to  claim 1 , characterized in that the web form paper or board ( 7 ) contains marks ( 5 ) made with a laser beam and these marks are embedded inside the layer-structure. 
   
   
       12 . A paper or board according to  claim 11 , characterized in that the web is rolled around a drum or core. 
   
   
       13 . A layer-structured board ( 7 ) containing identification marks that can be manufactured with a method according to  claim 1 , characterized in that the board contains marks ( 5 ) made with a laser beam, and the marks are embedded inside the structure formed by a series of fiber layers ( 6 ,  1 ,  8 ) of the board. 
   
   
       14 . Board according to  claim 13 , characterized in that the marks are darker figures. ( 5 ) on the surface of the fiber layer ( 1 ), made by the reaction induced with a laser beam. 
   
   
       15 . Board according to  claim 13 , characterized in that the marks are hollows ( 5 ′) cut with a laser beam on the fiber layer ( 1 ) and that these hollows are filled with a different type of material present in the next fiber layer ( 6 ). 
   
   
       16 . A board according to  claim 14 , characterized in that one of the fiber layers is of chemical pulp and the other of mechanical or chemical/mechanical pulp. 
   
   
       17 . A board according to  claim 13 , characterized in that it is a fold-carton formed of sulfate and CTMP layers.