高级检索
    张健, 罗斌, 刘红光, 李黎. 中密度纤维板和红松磨削过程材料去除机理的研究[J]. 北京林业大学学报, 2018, 40(11): 123-130. DOI: 10.13332/j.1000-1522.20180265
    引用本文: 张健, 罗斌, 刘红光, 李黎. 中密度纤维板和红松磨削过程材料去除机理的研究[J]. 北京林业大学学报, 2018, 40(11): 123-130. DOI: 10.13332/j.1000-1522.20180265
    Zhang Jian, Luo Bin, Liu Hongguang, Li Li. Material removal mechanism during MDF and Korean pine sanding processes[J]. Journal of Beijing Forestry University, 2018, 40(11): 123-130. DOI: 10.13332/j.1000-1522.20180265
    Citation: Zhang Jian, Luo Bin, Liu Hongguang, Li Li. Material removal mechanism during MDF and Korean pine sanding processes[J]. Journal of Beijing Forestry University, 2018, 40(11): 123-130. DOI: 10.13332/j.1000-1522.20180265

    中密度纤维板和红松磨削过程材料去除机理的研究

    Material removal mechanism during MDF and Korean pine sanding processes

    • 摘要:
      目的磨削作为一项木质材料精加工技术,研究木质材料磨削过程中的材料去除行为对提高磨削效率和加工表面质量具有重要意义。
      方法本研究设计了木质材料单磨粒磨削实验平台,采用横向划擦法,利用扫描电镜和3D轮廓仪考察了单磨粒在中密度纤维板(MDF)和红松(Pinus koraiensis)表面形成的划擦痕迹形貌,并测定了相关特征参数,分析了最大磨削深度、沟壑面积对隆起比的影响,并根据磨粒与试件接触过程中磨削力、综合摩擦系数的变化情况,研究磨粒引起的材料变形。定义λ为划擦方向与木材纹理方向之间的夹角。
      结果与金属磨削过程不同,中密度纤维板和红松划擦时形成的隆起区域很小。红松横纹划擦时(λ = 90°),被磨粒切刃横向割断的木材在试件表面形成断茬,局部接触区域发生压溃式切削。红松顺纹划擦时(λ = 0°),隆起比集中在0~0.05,而中密度纤维板的隆起比呈现高度离散。在对红松进行横纹划擦时,法向磨削力Fn和切向磨削力Ft均呈剧烈振荡,而在中密度纤维板和红松顺纹划擦过程中,FnFt都近似符合正态分布,并且随着磨粒切入试件深度的不断增加,FnFt均随之增大,最大值出现在最大切入深度处附近。就中密度纤维板而言,Fn大于Ft,而红松顺纹划擦时Ft略大于Fn。无论是中密度纤维板还是红松顺纹划擦时,磨粒切入试件形成沟壑后半段的综合摩擦系数略大于初期。
      结论红松磨削过程中,其内部的孔隙(如轴向管胞、解剖学上的植物内部腔洞等)分布和木材纹理方向对材料的变形流动、加工表面质量有着重要影响。中密度纤维板较红松而言,在磨削痕迹两侧产生较多的塑性隆起,隆起比随磨削深度、沟壑面积变化呈现高度离散。在磨粒切入试件过程中,磨粒所受的综合摩擦力是逐渐增大的。

       

      Abstract:
      ObjectiveAs for wood materials, sanding technology is an important fine machining method. Investigating material removal behavior in wood material sanding process is of great significance for improving sanding efficiency and surface quality.
      MethodIn this research, a single grit grinding platform was designed, and a traverse scratching method was used. The scratched surface morphology of medium density fiberboard (MDF) and Korean pine (Pinus koraiensis) was scanned and measured by SEM and 3D profiler to analyze the effects of maximum cutting depth and groove area on pile up ratio. Moreover, the variation of grinding forces and overall friction coefficient was analyzed to study material deformation. λ was defined as the angle between scratching direction and wood grain direction.
      ResultIn comparison with metal grinding, the pile up area was much smaller when scratching MDF and Korean pine. When λ = 90°, the wood substance was cut bilaterally by cutting edges and some deformed material remained on Korean pine workpiece surface like stubble, and some interaction area was crushed by grit. The pile up ratio of Korean pine (λ = 0°) was concentrated at 0 to 0.05 while that of MDF was highly scattered. Both the normal force Fn and the tangential force Ft oscillated highly during scratching Korean pine (λ = 90°). While in the process of scratching MDF and Korean pine (λ = 0°), both Fn and Ft demonstrated nearly a Gaussian normal shape. With the increasing penetration of grit into workpiece, both Fn and Ft increased, and the maximum force value occurred at about the maximum cutting depth. For MDF, Fn was larger than Ft, while for Korean pine, Ft was a little larger than Fn. During the process of scratching MDF and Korean pine (λ = 0°), the overall friction coefficient was slightly higher when grit reached the deepest point and started to exit workpiece.
      ConclusionDuring the grinding process of Korean pine, the inside pores (like axial tracheid and anatomic cavities) and wood grain direction exert great influence on material deformation and flow and surface quality. Compared with Korean pine, more plastic pile up occurres on bilateral sides of scratched groove when scratching MDF. And the variation of cutting depth and groove area on pile up ratio is highly scattered. As the grit penetrates into workpiece, the overall friction increases.

       

    /

    返回文章
    返回