Mania Przemysław, Gąsiorek Mateusz
Department of Wood Science and Thermal Technics, Faculty of Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 38/42, 60-627 Poznań, Poland.
Materials (Basel). 2020 Apr 22;13(8):1962. doi: 10.3390/ma13081962.
Wedge-shaped boards of spruce wood ( Karst.) are used to make violin fronts, also known as soundboards. Oil-heat treatment (OHT) can influence the acoustic properties of resonant wood, such as spruce. In this study, the effect of OHT on spruce wood was evaluated, using palm oil as a heating medium, at four different temperatures: 140, 160, 180 and 200 °C. Physical, mechanical and acoustic properties of spruce wood were evaluated before and after OHT and included the following: density, modulus of elasticity in the static bending test, and wood sound velocity. The acoustic parameters after OHT improved; however, the samples bent after modification had a higher modulus of elasticity, with a simultaneous deterioration of the acoustic parameters. The dynamic modulus of elasticity increased by 11%, and the musical constant by 5%. The static modulus increased by more than 3.5%, but the acoustic parameters calculated on the basis of these results indicated a deterioration of the acoustic properties of completely oven-dried wood. The increase in moisture content to air-dried condition contributed to a slight increase in the mean musical constant at the highest modification temperature.
云杉木（喀斯特）制成的楔形木板用于制作小提琴的正面，也称为音板。油热处理（OHT）会影响共振木材（如云杉）的声学特性。在本研究中，以棕榈油作为加热介质，在140、160、180和200°C这四个不同温度下评估了油热处理对云杉木的影响。在油热处理前后评估了云杉木的物理、机械和声学特性，包括以下方面：密度、静态弯曲试验中的弹性模量以及木材声速。油热处理后的声学参数有所改善；然而，改性后弯曲的样品具有更高的弹性模量，同时声学参数有所恶化。动态弹性模量增加了11%，音乐常数增加了5%。静态模量增加超过3.5%，但基于这些结果计算出的声学参数表明完全烘干木材的声学性能有所恶化。在最高改性温度下，将水分含量增加到风干状态有助于平均音乐常数略有增加。
