American Journal of Applied Sciences 5 (8): 990-996, 2008 ISSN 1546-9239 © 2008 Science Publications Corresponding Author: Nukman Yusoff, Department of Engineering Design and Manufacture, Faculty of Engineering, Universiti Malaya, 50603 Kualalumpur, Malaysia 990 Selected Malaysian Wood CO 2 -Laser Cutting Parameters And Cut Quality Nukman Yusoff, Saiful Rizal Ismail, Azuddin Mamat and Aznijar Ahmad-Yazid Department of Engineering Design and Manufacture, Faculty of Engineering, Universiti Malaya, 50603 Kualalumpur, Malaysia Abstract: Laser has been used to cut most non-metallic materials very efficiently and successfully because these materials are highly absorptive by the CO 2 laser wavelength of 10.6m. Laser cutting process has been found to be reliable in loads of applications, with several advantages over other mechanical means in producing successful cut of even thermally sensitive materials such as wood. Various works which have been conducted to resolve the interaction between laser and wood but an ultimate guideline to produce the best cutting results are still undecided. This latest experiment was performed on Malaysian light hardwood namely, Nyatoh (Palaquium spp.), Kembang Semangkok (Scaphium spp.), Meranti (Shorea spp.) and normal Plywood using low power carbon dioxide laser machine with 500 Watt maximum output. The low power laser machine (Zech Laser model ZL 1010), equipped with a slow flow CO 2 laser producing maximum output power of 500 watt on beam mode of TEM01 is employed. The processing variables taken into investigation were laser power, nozzle- standoff distance (SOD) or focal point position, nozzle size, assist gas pressure, types of assist gas, cutting speed and delay time. The wood properties observed were thickness, density and moisture content of the wood. The analyses considered were of the geometric and dimensional accuracy (straight sideline length, diameter of circle, kerf width, and percent over cut), material removal rate, and severity of burns of the matters upon machining with compressed air or any assist gases. The relationship between processing parameters and types of wood with different properties were outlined in terms of optimum cutting conditions, the minimum burnt-effect achievable and the best cut quality obtained with minimal surface deterioration and acceptable in accuracy. From this present study a guideline for cutting a wide range of Malaysian wood has been outlined. Key words: Materials processing, laser cutting, wood machining parameters INTRODUCTION Laser machining of wood has not been widely accepted by wood industry, although several successful CO 2 laser cutting applications have been reported by Mukherjee et al. [1] . An example of CO 2 laser cutting of wood is highlighted by Lum et.al. [2] in their experiment in determining the process parameter settings for the cutting of medium density fibreboard (MDF). Lum et.al. indicated that laser cutting is a type of thermo chemical decomposition (TCD) mechanism. The energy from the laser beam acts to break chemical bonds and thus disrupt the integrity of the material. Khan et al [3] have highlighted the importance of parameters like laser power, cutting speed and shield gas to determine the cut quality for both hard and soft timber materials. Both Mukherjee et al. [1] and Khan et al [3] have also commented on how nozzle design and variation in shield gas velocity could improve the cutting performance of CO 2 lasers on timber-based materials. However, one of the important factors is laser cutting speed because higher cutting speed can achieve lower production as a result of lower cycle time. Shield gas pressure are depended upon the nozzle size and in case of supply gas in cylinder, the amount of gas remaining inside the cylinder can also affects the gas pressure. Barnekov et al. [4,5] have twice highlighted on the location of the laser focal point with respect to the workpiece also affecting cutting efficiency. The authors have found that the severance energy which is laser power divide by material thickness for the material is about 1 J mm 2 . The interaction of the laser beam with wood is mainly determined by the type of laser being used. The CO 2 laser beam is absorbed almost completely by wood, as proven by Grad and Mozina [6] . This is the