Modeling of the Laser Engraving at Plasma Sprayed AI2O3, TiO2 and AI2TiO5 Coatings for Anilox Rolls

Paper presents a study of modeling and numerical simulation of laser engraving process. The 1-D simulation concerned CO2 c.w. pulsed laser engraving of plasma sprayed alumina, titania and aluminum titanate coatings. These coatings will possibly replace the Cr2O3 ones used currently in manufacturing of anilox rolls. The model was refined in comparison to the previous one (1) by taking into account the speed of the roll at the engraving. The actual thermophysical coefficients of plasma sprayed alumina, titania and aluminum titanate were input to the computations. The model enabled calculation of the engraving's depth in function of the principal laser treatment parameters viz. pulse length and laser power density. Finally, the overflow effect at the laser treatment of new ceramics was discussed and compared to that occurring at Cr2O3 engraving.

Modeling of the Laser Engraving at Plasma Sprayed Cr2O3 Coatings on Anilox Rolls

This paper presents a preliminary study of mathematical modeling and numerical simulation of laser engraving process. The 1-D simulation concerned CO2 c. w. pulsed laser engraving of plasma sprayed Cr2O3 coatings as used in the manufacture of anilox rolls. The thickness of the evaporated material was calculated as a function of laser processing parameters viz. pulse length and power density. The actual thermophysical coefficients of plasma sprayed chromia were used if available and the results of calculated thickness of evaporated layer are compared with the experimentally determined depth of engraved cells to estimate unknown coefficients of liquid chromia. Finally, the experimental effect of overflow was related to the calculated thickness of liquid layer. The experimental procedure of minimization of this effect is proposed.