木质材料激光表面处理研究进展

激光以其能量密度高、运行轨迹自如、方向性好等优点,被广泛用于木质材料切削加工以及表面处理等领域。其中,木质材料激光表面处理,即利用激光热/光电子效应促进材料发生物理、化学变化,以实现改性的目的。笔者对木质材料激光表面处理原理、激光类型与用途以及激光表面处理技术特点与应用领域等内容的研究现状进行了综述与分析。现有研究表明:材料对于不同波长激光的吸收系数差异明显,基于此特性可实现木质材料表层激光选择性消融,以满足不同应用场合的加工需求;其次,激光功率、激光扫描路径密度以及进给速度等激光工艺参数,决定了表面处理过程中能量密度及分布,进而影响木质材料表面改性强度与深度,通过对激光参数的优化可实现木质材料表面部分性能(如表面颜色、润湿性、功能性结构等)的精准改性。最后,还探讨了木质材料激光表面处理领域研究现状与趋势,阐明了研究的科学意义和未来研究方向,以期为创新木质材料表面处理技术、实现其提质增效提供理论指导,也为拓宽激光技术在木质材料加工领域的应用范围提供思路。

Research progress on laser surface treatment of wood materials

Due to the defects of unstable shape,mildew,discoloration,etc.,the wood materials as natural fiber materials normally need to be modified by chemical or physical treatments.Thermal treatment is a kind of frequently used method,which could improve the properties of wood materials.Conventional thermal treatment process generally requires the equipment to have good pressure resistance,suitable sealing and other well-behaved performance.The manufacturing process and performance of the equipment are put forward very high requirements,inevitably brings the problems of high equipment investment,small volume,low efficiency,and high energy consumption.Aiming at solving these problems,the optimization and innovation of wood thermal treatment technology have been investigated by many researchers.The research and exploration of new wood thermal treatment modification mechanism will become the key fundamental problem to be solved urgently in the field of wood thermal treatment.The better choice to improve the efficiency and economic benefits of wood thermal treatment is to create a novel processing.Laser has the advantages of high energy density,easy running track and good direction,etc.It has been widely used for cutting and surface treatment of wood materials.Among them,the laser surface treatment technology for wood materials is based on the laser thermal effect,force effect and light effect to promote the physical and chemical changes of wood components,aiming at achieving the selective modification of wood materials.This study summarized and analyzed the research status of laser surface treatment principle,laser types and applications,and characteristics and application of laser surface treatment technology for wood materials.The results of the present research showed that different materials have different absorption coefficients of laser with different wave lengths.In view of this,the laser can be used for selective laser ablation of the wood materials’ surface layer,satisfying different applications.The laser power,scanning path density,feed speed and focus length determined the energy density on wood materials surface during the laser treatment,which affected the strength and depth of the modification.The correlation of surface performance(such as color,wettability,functional structure,etc.) and laser parameters could be modeled,and the precise modification could be achieved by optimizing laser modification parameters.The research trend and deficiency of the laser surface treatment of wood materials were discussed,and the scientific significance of the research and the future research direction were also discussed,which can provide theoretical guidance for the innovation of wood material surface treatment technology,and broaden the range of application of laser technology in wood processing.