INVESTIGATION OF THE LASER ENGRAVING OF AISI 304 STAINLESS STEEL USING A RESPONSE-SURFACE METHODOLOGY

In this paper we present the laser-beam engraving of a cold-rolled AISI 304 stainless-steel plate used for intaglio printing (e.g., banknotes and passports). This intaglio printing process allows the ink from a desired engraved pattern (e.g., microletters and images) to be transferred to a sheet of paper. The intensity of the colour and the ability to prevent the forgery of raised characters that appear on the paper correspond to the channel geometries formed by the laser-beam engraving. In order to obtain the appropriate channel geometry, and to avoid time-consuming, trial-and-error experiments, the engraving parameters must be optimized. For this purpose the Design of Experiments method and the orthogonal array L-27 (3(4)) were selected. A statistical analysis ANOVA at the 95 % confidence level was performed using the statistical software. It was found that the scan speed is the most significant factor affecting the groove geometry.