Coextrusion of periodically modulated structures
A method for manufacturing a foil having a variable strip geometry, which makes it possible to supply a foil that bears a complex security feature. Varying of the geometry is effected by means of a movement of a position-variable distributor rail of the extruder.
1. A method for manufacturing a foil having a variable strip geometry for employment in a data carrier, having:
extrusion of at least one first surface and at least one second surface, in such a manner that the surfaces form the foil in a sequence that alternates orthogonally to an extrusion direction, wherein a varying is effected of at least one of the surfaces with respect to its geometry;
wherein the varying of the geometry's effected by means of a movement of a position-variable distributor rail of an extruder;
wherein the variable strip geometry comprises an individually adjustable pattern defined as adapting individual strips of the at least one first surface and the at least one second surface with respect to width and in extension along a length of the individual strips;
wherein the position-variable distributor rail comprises a first position, the first position defining a first height of the position-variable distributor rail in the extrusion direction, and second position, the second position defining a second height of the position-variable distributor rail in the extrusion direction, wherein the first height varies from the second height.
2. The method according to claim 1 , wherein the varying of the geometry is effected in the extrusion direction and/or orthogonally to the extrusion direction.
3. The method according to claim 1 , wherein the at least one first surface and the at least one second surface differ with respect to their width.
4. The method according to claim 1 , wherein several first surfaces and several second surfaces are provided, wherein the first surfaces are of equal width and the second surfaces are of equal width.
5. The method according to claim 1 , wherein at least one of the surfaces is formed from different materials.
6. The method according to claim 1 , wherein at least one of the surfaces is composed of several partial surfaces.
7. The method according to claim 1 , wherein at least one of the surfaces is formed in a meandering manner, strip-shaped manner and/or with varying width.
8. The method according to claim 1 , wherein at least one of the surfaces is arranged diagonally within a foil surface.
9. The method according to claim 1 , wherein color pixels are arranged on the foil by means of a matrix block having punctiform and/or elliptical passages.