Rough surface finishing of stone-faced sandwich panels using high pressure waterjet

The natural stone veneer used to clad sandwich panels needs to be less than 1 cm thick to ensure a lightweight structure. However, diminishing the thickness reduces slab strength, which is important when the stone is to be rough finished. Thus, traditional techniques such as bush-hammering and flaming are unfeasible for these veneers. The main aim of this study was to investigate the possibility of using high pressure waterjet technology for stone veneer finishing. First, the characteristics of the stone were determined (origin, petrography chemistry, strength). Suitable combinations of waterjet operating parameters (pressure, traverse speed, distance between successive passes) were then tested to determine optimal results in terms of both performance and aesthetics. The investigation demonstrated the success of this technique for processing large slabs (100 cm × 200 cm), with thickness of just 3 mm, thus also overcoming the problems involved in maneuvering heavy slabs with thickness of more than 2 cm. Surface roughness analysis of the treated stone showed it to compare favorably with competing technologies, with the advantage that waterjet maintains the natural color of the rock. Finally, some economic considerations are discussed.