Morphology, mechanism and kerf variation during CO2 laser cutting pine wood

Abstract

As laser cutting is a complicated process, characterizing the kerf surface morphology is essential to gain deep insight into the mechanism of laser cutting wood, and exploring an appropriate combination of processing parameters is also of great necessity to realize higher efficiency and greater yield. In this work, the cutting of pine wood ( Picea jezoen, s—sCalx. ) with a CO 2 laser was studied. The morphology and processing-induced defects for the kerf surface were characterized to investigate the mechanism for the laser cutting of wood. Analysis of variance and the significant contribution of each parameter were adopted to explore the effects of processing parameters on kerf depth and width. The results show that processing-induced defects such as goosebump-like morphology, striations, charring and debris can be observed on the kerf surface. The cutting-off mechanism is the result of the combined action of the laser beam and gas jet. The typical kerf is V-shaped. However, the variation in structure and density between earlywood and latewood will result in an irregular shape. A better cutting effect for a higher efficiency can be achieved by cutting wood with a lower moisture content at a lower speed in parallel to the fiber direction, and a greater yield can be achieved by cutting wood with a higher moisture content at a higher speed in parallel to the fiber direction. This work provides deep insight into the mechanism for laser cutting wood and reveals that CO 2 lasers show great potential to cut wood.