METHOD AND DEVICE FOR PRODUCING A STRUCTURED SURFACE ON A STEEL EMBOSSING ROLLER

摘要

The method for structuring the surface of a steel embossing roller by means of short pulse laser, where the structuring is a macrostructuring with dimensions of over 20 mum and depths up to 150 mum and more, distinguishes itself by the following parameter combination: a) in single pulse operation a fluence in the range of 0.5 J/cm2 to 3.5 J/cm2 and in burst operation a mean burst fluence of 0.5 J/cm2 to 70 J/cm2 per pulse, b) wavelength of 532 nm to 1064 nm, c) repetition rate of 1 kHz to 10 MHz, d) pulse to pulse spacing on the workpiece of 10 % to 50 % of the beam diameter for the femtosecond laser and of 10 - 25 % and 40 - 50 % of the beam width for the picosecond laser, e) laser pulse position near the workpiece surface, and f) deflection velocities of up to 100 m/s and more. *** Such a method allow manufacturing a complete embossing roller with teeth and gaps for producing logos, the teeth having variable heights, shapes, and spacings, for embossing e.g. innerliners for cigarette packaging.