Lamination Cylinder

Abstract

A lamination cylinder includes a surface structure, on which a plurality of craters is defined having a different geometry and a random distribution. Some of the craters are partially superimposed with respect to each other.

The invention claimed is: 
     
         1 . A lamination cylinder comprising:
 a surface structure on which a plurality of craters is defined, said craters having different geometries and being distributed along a helical path,   wherein some of said plurality of craters are partially superimposed with respect to each other,   wherein some of said plurality of craters are at least partially surrounded by a ridge,   wherein said plurality of craters comprises circular craters and oval craters,   wherein said plurality of craters is obtained with a pulsed laser beam in constant power mode and by varying a duration of the pulsed laser beam within random time intervals, such to obtain said craters with different and random dimensions in terms of crater diameter, crater length along said helical path, crater depth, height of crater ridge, and distance between neighboring craters, and   wherein use of the laser causes an increased hardness of a surface of the lamination cylinder, thereby causing the lamination cylinder to tolerate longer lamination processes without loss of quality of a laminated product.   
     
     
         2 . The lamination cylinder according to  claim 1 , wherein said plurality of craters are rounded. 
     
     
         3 . The lamination cylinder according to  claim 1 , wherein said circular craters are partially superimposed over said oval craters. 
     
     
         4 . The lamination cylinder according to  claim 1 , wherein said oval craters are partially superimposed over each other. 
     
     
         5 . The lamination cylinder according to  claim 1 , wherein said circular craters are partially superimposed over said oval craters, and said oval craters are partially superimposed over each other, and wherein said circular craters and said oval craters are in turn partially superimposed in order to define a predetermined roughness. 
     
     
         6 . The lamination cylinder according to  claim 1 , further comprising smooth areas between at least some of said craters. 
     
     
         7 . The lamination cylinder according to  claim 1 , wherein said craters are distributed along a plurality of helical paths. 
     
     
         8 . The lamination cylinder according to  claim 7 , wherein said plurality of helical paths have varying distances therebetween. 
     
     
         9 . A method of etching a lamination cylinder comprising:
 providing the lamination cylinder; and   defining a plurality of craters on the lamination cylinder, the plurality of craters having different geometries and being distributed along one or more helical paths partially superimposed with respect to each other, some of the plurality of craters being at least partially surrounded by a ridge,   wherein the step of defining the plurality of craters comprises:   rotating the lamination cylinder around a longitudinal axis; and   etching the lamination cylinder with a laser beam along the one or more helical paths,   wherein the laser beam is pulsed in constant power mode at varying intervals of time and for varying durations within random time intervals, such to obtain said craters with different and random dimensions in terms of crater diameter, crater length along said one or more helical paths, crater depth, height of crater ridge, and distance between neighboring craters, thereby causing some of plurality of the craters to be partially superimposed with respect to each other, and   wherein use of the laser beam causes an increased hardness of a surface of the lamination cylinder, thereby causing the lamination cylinder to tolerate longer lamination processes without loss of quality of a laminated product.   
     
     
         10 . The method according to  claim 8 , wherein the laser beam is pulsed to cause some of the plurality of craters to have a circular perimeter and some of the plurality of craters to have an elongated perimeter. 
     
     
         11 . The method according to  claim 9 , wherein there is a single helical path. 
     
     
         12 . The method according to  claim 9 , wherein there is a plurality of helical paths. 
     
     
         13 . A method of etching a lamination cylinder comprising:
 providing the lamination cylinder; and   defining a plurality of craters on the lamination cylinder, the plurality of craters having different geometries being partially superimposed with respect to each other along a helical path, some of said plurality of craters being at least partially surrounded by a ridge,   wherein the step of defining the plurality of craters comprises:   rotating the lamination cylinder around a longitudinal axis; and   etching the lamination cylinder with a laser beam along one or more helical patterns,   wherein the laser beam is pulsed at varying intervals of time in constant power mode and for varying durations within random time intervals, thereby causing the craters to achieve random dimensions in terms of crater diameter, crater length along said one or more helical patterns, crater depth, height of crater ridge, and distance between neighboring craters and further causing some of the plurality of craters to be partially superimposed with respect to each other, and   wherein emission power of the laser beam is modulated according to a constant signal, to which a random signal is added, thus allowing dimensions and depths of the craters to be varied.