Multilayer card of thermoplastic material and a method of making the multilayer card secure

1. A multilayer card of thermoplastic material comprising a protective layer and a core layer secured to each other and an intermediate layer extending between the protective layer and the core layer, the protective layer being the outermost layer of the card, the card including at least one reinforced bonding zone extending through the printed layer between the protective layer and the core layer, wherein said intermediate layer has printing on a surface of said intermediate layer next to said protective layer and said reinforced bonding zone is comprised of material from said protective layer.

2. A multilayer card according to claim 1 , wherein the protective layer and the core layer are made of the same thermoplastic material or of thermoplastic materials that are weldable to each other, and at least the protective layer includes a portion passing through the printed layer and welded to a corresponding portion of the core layer.

3. A multilayer card according to claim 1 , wherein the card includes at least two contiguous edges forming an angle between each other, and the reinforced bonding zone is located in the vicinity of the intersection between the two edges.

4. A method of making secure a multilayer card of thermoplastic material comprising at least a protective layer, an intermediate layer and a core layer that are bonded together by lamination, the intermediate layer extending between the protective layer and the core layer, the method including the step of locally forming at least one additional bond directly between the protective layer and the core layer after the layers have been laminated together, wherein said intermediate layer has printing on a surface of said intermediate layer next to said protective layer and said at least one additional bond is comprised of material from said protective layer.

5. A method according to claim 4 , wherein the additional bond is made by welding by pressing and welding together facing portions of the protective layer and of the core layer.

6. A method according to claim 5 , wherein the welding parameters are selected in such a manner as to cause the intermediate layer to soften in such a manner that the portions for welding together can be brought into contact with each other through the intermediate layer.

7. A method according to claim 5 , wherein welding is performed in such a manner as to leave plastic deformation in the surface of an outside face of at least one of the protective layer and the core layer.

8. A multilayer card according to claim 1 , wherein the reinforced bonding zone includes a plastic deformation on a surface of the card.

9. A multilayer card according to claim 1 , wherein the reinforced bonding zone is a portion of the protective layer heat sealed to a corresponding portion of the core layer.

10. A method according to claim 4 wherein the at least one additional bond is formed by heat sealing using a hot punch.

11. A method according to claim 4 , wherein the core layer and the protective layer are pressed together and welded.