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題 名 | 應用化學處理改善絃樂器用木材之音響性質=Improvement of the Acoustic Properties of Wood for Stringed Instruments with Chemical Treatment |
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作 者 | 卓志隆; | 書刊名 | 林產工業 |
卷 期 | 22:4 民92.12 |
頁 次 | 頁265-273 |
分類號 | 474.18 |
關鍵詞 | 絃樂器; 三聚甲醛; 低分子量酚甲醛樹脂; 比動彈性係數; 內部摩擦; Stringed instrument; Trioxane; Low molecular weight phenolic resin; Specific dynamic young's modulus; Internal friction; |
語 文 | 中文(Chinese) |
中文摘要 | 長久以來木材即是重要的樂器用材,雲杉屬木材是作為絃樂器主要的面板用材,背板則主要使用槭木屬木材。由於森林保育及歐洲地區雲杉受酸雨影響,導致優良樂器用材供應短缺,因此如何提昇低品質用材的音響性質,實屬當務之急。同時因台灣地區相對溼度高,會對樂器品質造成很大的負面影響,同時樂器尺寸的變化也較大。故本研究採用三聚甲醛及低分子量酚甲醛樹脂處理西的加雲杉及槭木,探討木材經此化學處理後尺寸安定及音響性質的改善效果。結果顯示兩種藥劑對木材縱向及徑向音響性質及尺寸安定性都有明顯的提昇,但對徑向的音響性質改善效果較顯著。三聚甲醛以濃度4.0 x 10^(-3) mol/dm^3二氧化硫作為觸媒時,改善效果以溫度100°C處理者最佳,此時縱向、徑向的比動彈性係數分別增加2%及13%,內部摩擦減低24%及25%,抗膨潤效能約65%。低分子量酚甲醛樹脂處理的最佳條件為濃度10%,乾燥硬化溫度80°C,乾燥時間72小時,在此條件下對西的加雲杉木材音響性質的改善效果會顯著優於三聚甲醛處理者,但尺寸安定化則較差,此條件下的徑向比動彈性係數增加42%,內部摩擦減低52%。另外就藥劑處理方法的難易程度及成本因素等加以考量,低分子量酚甲醛樹脂是較適當的改善絃樂器用木材音響性質的藥劑。 |
英文摘要 | Wood has been used as the material for the manufacturing of musical instruments since ancient times. Typically, wood of the Picea and Acer genus are primarily used for the top plate and back plate of violin family instruments respectively. Improvement of acoustic properties of low quality wood for stringed instrument is very important. This would solve a problem originating in the short supply of high quality wood for musical instruments caused by forest conservation and the reduction in supply of European spruce due to acid rain. In the meantime, tonal quality and dimension of stringed instruments will greatly change and getting worse as exposed to high relative humidity in Taiwan. This study investigates improvement of the acoustic properties and stability of sitka spruce and maple for stringed instruments by two chemical treatments (formalization with trioxane and low molecular weight phenolic resin). The experimental results indicated that both chemical treatments increased the specific dynamic Young's modulus and greatly decreased internal friction without greatly increasing specific gravity. The degree of improvement of acoustic properties was better for radial direction specimens than for longitudinal direction. The optimum conditions treated with trioxane for the dimensional stabilization and improvement of acoustic properties were found to be 100 °C in the presence of sulfur dioxide as a catalyst. The results of flexural vibration tests showed that specific dynamic Young's modulus increased 2% and 13% in the longitudinal and radial directions respectively, and the internal friction decreased 24% and 25% in these directions respectively under above-mentioned. The antiswelling efficiency and the moisture excluding efficiency increased about 60% and 50% respectively. The optimum weight percent concentration, temperature and drying duration of low molecular weight phenolic resin for improvement of acoustic properties and dimensional stability were 10%、80°C and 72 hours respectively. Under this kind of treatment, the degree of improvement of acoustic properties of sitka spruce was better than that treated with trioxane. But the dimensional stabilization effect was inferior than those with trioxane treated specimens. The results under this situation showed that dynamic Young's modulus increased 5% and 42% in the longitudinal and radial directions respectively, and increased 5% and 51% for maple in these directions. The internal friction of sikta spruce decreased 35% and 52% in the longitudinal and radial directions respectively, while decreased 29% and 32% for maple in these directions. Because the low molecular weight phenolic resin was easier to deal with than trioxane and the cost of trioxane chemical is more expensive than phenolic resin. The more appropri ate chemical for the improvement of acoustic properties of wood for stringed instruments is low molecular weight phenolic resin. |
本系統中英文摘要資訊取自各篇刊載內容。