音響喇叭箱用粒片板之研製（一）膠合劑與粒片板比重對振動特性之影響

Manufacturing of Particleboards for Acoustic Cabinets (Ⅰ) Effects of Adhesives and Board Density on Vibrational Properties of the Particleboard

黃彥三(Yan-San Huang) ； 黃國雄(Gwo-Shyong Hwang) ； 張上鎮(Shang-Tzen Chang) ； 吳政道(Jeng-Dow Wu)

《林業試驗所研究報告季刊》 4卷2期 (1989/06) Pp. 83-95

https://doi.org/10.7075/BTFRI.198906.0083

摘要

木研究計畫旨在探討高衰減作用粒片板之製造，謀求改善國產粒片板之振動特性，作為喇叭箱之材料，藉以提高喇叭箱之附加價值與市場競爭力。因而採用具有塑性性質之EVA 膠合劑製造粒片板，並測其振動特性，同時其強度性質與厚度膨脹率亦予以測試。
試驗之結果歸結如下：
1．粒片板之強度性質隨EVA膠合劑混合比之增加而降低，厚度膨脹率則隨之而增加。
2．在不同膠合劑之種類與混合比下，強度性質隨比重之增加而增加，然厚度膨脹率受比重增加之影響不明顯。
3．對數衰減率及損失彈性便數隨EVA膠合劑混合比之增加而顯著增加。
4．對數衰減率不受比重增加之影響，而損失彈性係數隨比重增加而有明顯增加之趨勢。
5．粒片板之音速隨EVA膠合劑混合比之增加而降低。
6．音速隨比重之增加而有略增之趨勢。

關鍵字

粒片板 ； 自由振動 ； 對數衰減率 ； 損失彈性係數 ； 動彈性係數 ； 音速

並列摘要

Particleboard is often used to make speaker carbinets. Performance of the speaker cabinets can be enhanced by modifying the physical properties of the particleboard used. Value of the particleboard in turn depends on its acoustic performance. The objective of this research is to study the vibrational properties, especially, the effects of adhesives and particleboard density on the acoustic characteristics of the board. Elastic vinylacetate copolymers were used as adhesive modifiers in making the particleboards. Vibrational experiments were conducted to measure the damping properties of the particleboards, such as elastic moduli, loss moduli and logarithmic decrements. Other physical and mechanical properties of the particleboards were also measured.
The experimental results are summarized as follows:
1.　Increase the ratio of ethylene vinylacetate (EVA) component in the adhesive formulation results in decreased mechanical strength of the particleboards, whereas thickness swelling of the particleboards is increased.
2. Mechanical strength of the particleboards increases with board density. The effect of board density on thickness swelling, however, is negligible.
3. Logarithmic decrements and loss moduli of the particleboards increase significantly with increasing ratio of EVA in the adhesive.
4. There is no apparent relationship between logarithmic decrements and the particleboard density, but loss moduli of the particleboards decrease significantly with increasing board density.
5. Sound speed transmitted by the particleboards decreases with in creasing ratio of EVA in the adhesive, and tends to increase slightly with increasing board density.

並列關鍵字

particleboard ； damping property ； free vibration ； logarithmic decrement ； loss modulus ； dynamic modulus ； souhd speed