THE DRILLING OF SLATE TILES BY A ND-YAG LASER

We have undertaken a series of experiments to investigate the feasibil ity of using a Nd:YAG laser to drill slate tiles. Slate is used primar ily as a roof building material after it is split into thin flat layer s. The traditional fixation system of slate tiles in Europe consists o f clamping the slate pieces by means of metallic clamps and overlappin g the different tiles in order to form an impervious roof. An alternat ive to this clamping technique, is the use of nails to fix the slate t iles to a wooden frame. This method improves the fixation of the slate tiles and reduces the costs related to roof repair by extending the p eriod between maintenance. However, the use of nails requires the prod uction of holes in the slate pieces, which is currently achieved by a mechanical route that results in large holes and an extended manufactu ring time. The aim of this work is to explore the capabilities of a pu lsed Nd:YAG laser to drill tiny holes in slate tiles in order to produ ce a better quality drilled slate tile in a reduced time. Shallow hole s were produced in slate samples using a 1 kW Nd:YAG pulsed laser focu sed onto the slate surface by an 80 mm fused silica lens. The results obtained in this study shows the enormous potential of Nd:YAG lasers i n the production of slate tiles.