Diode Laser Cure of Thermosetting Powders for Writing on Painted and Unpainted Metallic Surfaces

This paper describes an innovative system to make writings or patterns on painted or unpainted metallic surfaces by diode laser cure of thermosetting powders. The process is very interesting to personalize objects such as automotive components and others. An electrostatic deposition of commercial thermosetting powder is performed on metallic surfaces, the laser beam passes on the deposited powder following a fixed path and cures it. A process map was found in terms of laser power and scan speed. The laser power is in the range 55–70 W for a scan speed of 1 or 2 mm/s in the case of metallic surfaces, while the power is in the range 35–50 W for the same scan speeds in the case of painted surfaces. Visual inspection and scratch tests were performed in order to evaluate the aspect and the adhesion to the substrate. Very good results were found demonstrating that the diode laser is a useful tool to make writing.