Optimization of laser drilling of slate tiles

Slate is a natural rock with good mechanical properties and nice aesthetic appearance. Its utilization in residential constructions confers an elegant rustic external appearance, while keeping an excellent impermeability and robustness. Therefore, this rock is widely used in building construction, decoration, fireplaces and even handcrafted objects, particularly in regions owning natural slate quarries.The modern building construction is nowadays asking for improved manufacturing processes for its roofing materials since market requirements are continuously increasing. However, there is currently a lack of a reliable drilling process for slate. Making drills on a slate tile is still a difficult task because of its high hardness and its particular structure with parallel layers. A significant number of slate tiles are broken due to mechanical stress caused by traditional drilling tools. In this sense, lasers have already been demonstrated as a reliable tool for generate holes on a wide variety of materials and, particularly, in some stones. Due to its high precision, energy density, and its availability to be automated a great number of small holes can be produce in a short period of time.In this work, an experimental analysis on the CO2 laser drilling process of slate tiles is presented. We have used a systematic approach to determine the most adequate processing conditions to produce submillimeter holes in 5 mm thick slate tiles with good quality as well as in a minimum processing time.Slate is a natural rock with good mechanical properties and nice aesthetic appearance. Its utilization in residential constructions confers an elegant rustic external appearance, while keeping an excellent impermeability and robustness. Therefore, this rock is widely used in building construction, decoration, fireplaces and even handcrafted objects, particularly in regions owning natural slate quarries.The modern building construction is nowadays asking for improved manufacturing processes for its roofing materials since market requirements are continuously increasing. However, there is currently a lack of a reliable drilling process for slate. Making drills on a slate tile is still a difficult task because of its high hardness and its particular structure with parallel layers. A significant number of slate tiles are broken due to mechanical stress caused by traditional drilling tools. In this sense, lasers have already been demonstrated as a reliable tool for generate holes on a wide variety of materials...