FFT頻譜分析應用於砂光面粗糙度評估之研究

木材鉋削加工面所留下之刀痕及各種切削缺點，須藉砂光作業來消除，作為木製品塗接前之準備，然木材為一生物性材料，因纖維走向及年輪之存在，使木材具有高度異向性。木材砂光面之性狀至為複雜，係由砂粒特性與木材組織構造所形成。用以表示表面粗糙程度之剖面曲線，可視為由不同波長與振幅影成的複雜波形。本研究利用FFT頻譜分析儀就剖面波形進行解析，探討加工面性狀之評估方法，試材選用橡膠木及橡木，以#80，#120，#150，#180，#240號砂帶進行帶式砂光機之砂磨試驗。試驗結果如下：1.鉋削面刀痕可以著色方式加以顯現，使肉眼更易辨認。2.鉋削加工面上之刀痕，若使用較#180為粗之砂紙，可經一次砂磨而加以去除。3.刀痕可利用FFT頻譜分析儀作定性，定量分析。4.利用FFT頻譜與頻度分析，可評估砂光面之粗糙情況，對於富異向性之木材，可發揮特殊之功能。5.除Ra與Rtm外，中量在砂光面粗糙度之評價上甚有價值。

關鍵字

頻譜分析；粗糙度；刀痕；中量；頻度； 1/3八度音程分析

並列摘要

The machining defects including knife marks should be removed by sanding process which is prerequisite for good finishing quality. Wood is a natural material and due to the presence of fiber orientation and annual rings, actually it is an anisotropic material. The profile Curve of wood surface roughness can be considered as a complicated wave which is produced from the combination of different wave length and amplitude. In this study FFT spectrum analyzer was applied to analyze the profile curve of wood surface roughness and accordingly evaluate the surface properties. Oak and rubber wood were examined in this study. The wood surface was belt-sanded with #80, #120, #150, #180 and #240 grit sand papers. The experimental results of this study are summarized as follows: 1. The knife marks can be evidenced by staining and thereby become easily recognized to the naked eye. 2. The knife marks produced from machining process can be removed by sanding once with #180 grit sand paper. 3. The knife marks on wood surfaces can be analyzed qualitatively and quantatively by using FFT spectrum analyzer. 4. The FFT spectrum and probability density analysis has been proved to be a potential technique to evaluate the roughness of wood surface after sanding by different grit sand papers. 5. Besides Ra and Rtm, median is a valuable parameter for the evaluation of sanding surface roughness.

並列關鍵字

Spectrum analysis ； roughness ； knife marks ； median ； probability ； 1/3 octave analysis

國際替代計量

FFT頻譜分析應用於砂光面粗糙度評估之研究

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