棕刚玉磨料砂带磨削木材的磨损机制及其寿命

Wear mechanism and life of brown corundum abrasive belt in wood sanding process

分析砂带磨削过程中的砂带磨损机理及其对材料去除率、表面粗糙度的影响,旨在进一步完善木材切削理论,推动新型砂带研发制造。以红松为试验材料,结合试件材料去除率、磨削过程中砂带的砂带表面算术平均高度Sa、磨粒峰度Sku以及表面形貌的变化,以试件表面算术平均高度Sa以及试件界面的展开面积比Sdr为考察指标,探究砂带的磨损机制及砂带磨损对红松表面粗糙度的影响,综合评判砂带寿命。同等工艺参数下,横纹磨削时材料去除率整体大于顺纹,其对砂带的磨损消耗整体小于顺纹。横纹磨削过程中,磨粒前期发生较多破碎与脱落,中期以磨粒不断更新自锐保持砂带的有效切削,后期磨粒脱落、磨损的占比大于破碎,最终砂带寿命趋于极限。顺纹磨削时,磨粒在前期破碎和磨钝占比更大,在磨削中期磨粒顶端逐渐磨钝,沿前期磨痕推除材料实现有效切削,在后期的磨粒除脱落外,再次发生破碎勾起木纤维,最终失效。砂带寿命在材料去除率达到5%左右时已达到使用极限,在实际木材磨削加工生产中判定砂带寿命时需综合考察砂带的材料去除率及试件的表面质量。

Belt sanding is an important technology in the wood processing industry.The purpose of this study was to further improve the theory of wood sanding and promote the development and manufacture of new sand belts by analyzing the wear mechanism of sand belts in the sanding process and its influence on the removal rate and surface roughness of wood materials.In this study,using Pinus koraiensis wood as experiment materials,the material removal rate of workpiece was analyzed.The arithmetic average height Sa of the abrasive belt surface,sanding grain of kurtosis Skuand the change of surface morphology of the abrasive belt surface were discussed.And the arithmetic average height Sa of the surface of the workpiece and the expanded area ratio Sdr of the workpiece interface were also used as the inspection indicators.The abrasive belt wear mechanism and the effect of abrasive belt wear on the surface roughness of Pinus koraiensis were explored,and comprehensively evaluated the abrasive belt life.With the same technological parameters,the removal rate of the transverse sanding was higher than that of the longitudinal sanding,and the wear consumption of belt was lower than that of the longitudinal sanding.In the process of the transverse sanding,more abrasive grains were broken and fell off in the initial stage.In the mid-stage,abrasive grains were constantly updated and self-sharpened to maintain the effective sanding of the belt.In the last phase,the proportion of abrasive grains fell off and the wear was greater than that of crushing,and the service life of the belt finally reached its limit.In the process of the longitudinal sanding,the proportion of sanding grains being broken and dulled was larger in the initial stage,and the top of grains was gradually dulled in the mid-stage.In the last phase,in addition to falling off,the grains were broken again and picked up the wood fiber,and finally the belt failed.The service life of the belt had reached the limit when the material removal rate reached about 5%.In determining the service life of the belt in the actual wood sanding process,the material removal rate of the belt and the surface quality of the test piece must be comprehensively examined.