Product Code: PIC06_1004

Laser Cutting and Joining of Wooden Materials: How Both Processes are Determined by the Heat Affected Zone
Authors:
Stephan Barcikowski, Laser Zentrum Hannover E.V.; Hannover Germany
Presented at PICALO 2006

Wood and wood-derived materials are the most important materials with a world production of roughly 109 tons per year. However, because of the continuous development of the thermal and mechanical properties of wood materials towards high-tech applications, increasingly precise manufacturing processes have become attractive. In this contribution, the potential of laser cutting as well as laser welding of wooden materials is examined by quality-relevant material and process parameters as well as the determination of related manufacturing costs. The heat-affected zones (HAZ) at laser-cut and laser-joint wooden surfaces is characterised measuring the temperature profile of the process within the cut kerf of particleboard and plywood. The HAZ of the CO2 laser cut and Nd:YAG laser joint pine surface is characterized using IR imaging and UV microspectrophotometry. The thermally induced changes in wood composition are analysed for lignins and carbohydrates. The chemical and structural modifications seem to be most intense at the laser treated surface and decrease to levelling off at 35-40 μm distance from the surface. Based on these findings, a recommendation for process and material parameters is given for laser cutting and laser joining. Finally, the results are compared to conventional wood cutting and wood joining techniques.