Local heat tempering with laser radiation for brilliant colors on glass surfaces

Nowadays, architects are designing buildings with colored glass panes over a range of sizes and shapes for indoor and outdoor glass components. For the production of these surface colored glass panes, only companies with large furnaces for the tempering of the colors can be commissioned. Therefore, the present research work is developing an industrial process for the local tempering of the color using laser radiation. For the investigations, the color is applied with a layer thickness of about 25 μm and then burned on the glass with CO2 laser radiation. The laser beam is guided and formed via a scanner. Process-specific parameters such as laser power and speed are varied in order to influence the energy per unit. When the value of the energy per unit is too high, glass damage can be observed. With the reduction of energy per unit, a color change and a tempering of the color are possible. For the evaluation of the quality, the results were examined microscopically. Then a specific set of parameters for the tempering of blue color with laser radiation was identified. Changes of color could be achieved with CO2 lasers. The results show that the laser tempered color is comparable with the color tempered in the furnace. In conclusion, with this process, the tempering process in a furnace could be substituted by a laser, and consequently small companies could be able to produce colored pictures on glass surfaces.