DOI QR코드

DOI QR Code

Effect of Heat Treatment on the Gas Permeability, Sound Absorption Coefficient, and Sound Transmission Loss of Paulownia tomentosa Wood

참오동나무의 열처리가 기체투과성, 흡음율과 음향투과손실에 미치는 영향

  • KANG, Chun-Won ;
  • JANG, Eun-Suk ;
  • JANG, Sang-Sik ;
  • Cho, Jae-Ik ;
  • KIM, Nam-Hun
  • Received : 2019.05.30
  • Accepted : 2019.08.23
  • Published : 2019.09.25

Abstract

In this study, the gas permeability, sound absorption coefficient, and sound transmission loss of the Paulownia tomentosa wood were estimated using capillary flow porometry, transfer function method, and transfer matrix method, respectively. The longitudinal specific permeability constant of the Paulownia tomentosa wood with a thickness of 20 mm was 0.254 for the control sample and 0.279, 0.314, and 0.452 after being subjected to heat treatments at $100^{\circ}C$, $160^{\circ}C$, and $200^{\circ}C$, respectively. The gas permeability was observed to be slightly increased by the heat treatment. The mean sound absorption coefficients of 20-mm thick Paulownia tomentosa log cross-section for the control sample and after being subjected to heat treatments at $100^{\circ}C$, $160^{\circ}C$, and $200^{\circ}C$ were 0.101, 0.109, 0.096 and 0.106, respectively. Further, the noise reduction coefficients of 20-mm thick Paulownia tomentosa log cross-section of the control sample and after being subjected to heat treatment at temperatures of $100^{\circ}C$, $160^{\circ}C$, and $200^{\circ}C$ were 0.060, 0.067, 0.062 and 0.071, respectively. The mean of sound transmission loss of the 20-mm thick Paulownia tomentosa log cross-section was approximately 36.93 dB. Furthermore, the gas permeability and sound absorption coefficient of the heat-treated Paulownia tomentosa discs slightly increased depending on the heat treatment temperature; however, the rate of increase was insignificant.

Keywords

Paulownia tomentosa wood;sound absorption coefficient;sound transmission loss;transfer function method;transfer matrix method

References

  1. ASTM E2611 - 09 Standard test method for measurement of normal incidence sound transmission of acoustical materials based on the transfer matrix method.
  2. ISO 10534-2, Acoustics-Determination of sound absorption coefficient and impedance in impedance tubes-Part 2: Transfer function method .
  3. Jang, E.-S., Kang, C.-W., Kang, H.-Y., Jang, S.-S. 2018. Sound absorption property of traditional Korean natural wallpaper (Hanji). Journal of the Korean Wood Science and Technology 46(6): 703-712.
  4. Kang, C.-W., Jang, E.-S., Jang, S.-S., Kang, H.-Y. 2018a. Comparison of transfer function method and reverberation room method in measuring the sound absorption coefficient of rice straw particle mat. Journal of the Korean Wood Science and Technology 46(4): 362-367.
  5. Kang, C.-W., Jang, E.-S., Jang, S.-S., Kang, H.-Y. 2018b. Measurement of sound transmission loss in a sound barrier filled with the rice-straw particles by the transfer function and laboratory measurement methods. Journal of the Korean Wood Science and Technology 46(4): 338-345.
  6. Kang, C.-W., Li, C., Jang, E.-S., Jang, S.-S., Kang, H.-Y. 2018c. Changes in sound absorption capability and air permeability of Malas (homalium foetidum) specimens after high temperature heat treatment. Journal of the Korean Wood Science and Technology 46(2): 149-154.
  7. Kang, C.-W., Lee, Y.-H., Kang, H.-Y., Kang, W., Xu, H.-R., Chung, W.-Y. 2011. Radial variation of sound absorption capability in the cross sectional surface of yellow poplar wood. Journal of the Korean Wood Science and Technology 39(4): 326-332. https://doi.org/10.5658/WOOD.2011.39.4.326
  8. Kang, C.-W., Oh, S.-W., Lee, T.-B., Kang, W., Matsumura, J. 2012. Sound absorption capability and mechanical properties of a composite rice hull and sawdust board. Journal of Wood Science 8: 273-278.
  9. Kang, H.-Y., Lu J. 2005. Comparison of longitudinal liquid permeability of Pinus Koraiensis sapwood treated by steaming and various drying methods. Journal of the Korean Wood Science and Technology 33(6): 17-24.
  10. Kim, D.-R., Kim, T.-M., Kim, J.-T., Park, G.-H., Ryu, L.-O. 2015. A study on sensitivity of transmission loss using scaled reverberation chamber. Transactions of the Korean Society of Noise and Vibration Engineering 4: 937-943.
  11. Kook, J.-H., Jung, C.-W., Yun, J.-H., Kim, J.-S. 2007. Experimental study on wall sound transmission loss at construction equipment machinery room. Proceedings of the Korean Society of Noise and Vibration Engineering 2007.3: 695-699.
  12. Lee, J.-H., Kim, B.-S., Kim, K.-J. 2011. Study of sound transmission characteristics of using a scale reverberation chamber and vibro acoustic FEM. Proceedings of the Korean Society of Noise and Vibration Engineering 10: 92-95.
  13. Kang, C.-W., Kim, G.-C., Park, H.-J., Lee, N.-H., Kang, W., Matsumura, J. 2010. Changes in permeability and sound absorption capability of yellow poplar wood by steam explosion treatment. Journal of the Faculty of Agriculture Kyushu University 55(2): 327-332.

Acknowledgement

Supported by : National Research Foundation of Korea (NRF)