The effect of preheating in nitrogen medium on acoustic properties of walnut and white mulberry | ||
| تحقیقات علوم چوب و کاغذ ایران | ||
| Article 4, Volume 34, Issue 3 - Serial Number 69, November 2019, Pages 349-360 PDF (975.26 K) | ||
| Document Type: Research Paper | ||
| DOI: 10.22092/ijwpr.2019.126610.1548 | ||
| Authors | ||
| Hadi Dashti1; Kambiz Pourtahmasi2; asghar tarmian* 3 | ||
| 1PhD. Student, Department of Wood and Paper Science & Technology, Faculty of Natural Resources, University of Tehran | ||
| 2Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran | ||
| 3Associate Proffesor | ||
| Abstract | ||
| In this research, the effect of preheating in nitrogen medium on acoustic properties of walnut and white mulberry’s boards was studied. Sapwood boards of 300×20×20 mm with the green moisture content were prepared. Heat treatments were applied at 140 and 160 oC under pressure of 2 pascal for 30 and 60 minutes. Following the heat treatment, the samples were dried in a convectional laboratory kiln of 8% at 50 oC, relative humidity of 50%, and air velocity of 1 m/s to the average final moisture content of 8%. Using the free vibration method on free- free bar, the dynamic modulus of elasticity and damping factor were evaluated. Results revealed that the heat-treatment at 140 oC for 30 minutes did not have a significant effect on vibration properties of the wood samples. On the other hand, the heat-treatment at 160 oC caused a significant increase in dynamic modulus of elasticity and also a reduction in the damping factor of walnut and white mulberry samples. The FTIR spectroscopy and X-ray studies showed that the degradation of cell-wall polymers and increase in the crystallinity of the walnut wood specimens occurred due to heat treatment at 160 0C. | ||
| Keywords | ||
| walnut; white mulberry; Damping factor; Modulus of Elasticity; Heat-treatment in nitrogen medium | ||
| References | ||
|
Bodig, J. and Jayne, B.A., 1982. Mechanics of Wood and Wood Composites. 712 Pp. -Boonstra, M. J.; Tjeerdsma, B. F. 2006. Chemical analysis of heat treated softwoods. Holz als Rohund Werkstoff 64(3): 204-211. -Esteves, B., Videira, R. and Pereira, J., 2010. Chemistry and ecotoxicity of heat-treated pine wood extractions, Wood Science & technology 45(4): 661-676. -Haines, D.W., 2000. The essential mechanical properties of wood prepared for musical instruments, CAS Journal. 4(2): 20–32. -Harris, Ciryl M., 1998. Shock and vibration handbook (6th Edition). McGraw-Hill, New York. 1168 pp. -ISO3129. 2012. Wood-sampling methods and general requirements for physical and mechanical testing of small clear wood specimens. International standard. Wood, sawlogs and sawn timber. -Kubojima, Y., 1998. Vibrational properties of Sitka spruce heat-treated in nitrogen gas. Journal of Wood Science. https://doi.org/10.1007/BF00521878 -Kranitz, K., Sonderegger, W., Bues, C. and Niemz, P., 2016. Effects of aging on wood: a literature review. Wood Science Technolgy. 50(1): 7-22. -Ma, L.N., 2005. On relationship between structure and acoustic properties of wood, Master's Thesis. Anhui Agricultural university, Hefei, China. -Matsunaga, M., 1999. Vibrational property changes of spruce wood by impregnation with water-soluble extractives of pernambuco (Guilandina echinata Spreng.), Journal of wood science vol, 45, pp. 470-474. -Militz, H., 2002. Thermal treament of wood. European processes and their backround. International Research Group on Wood Preservation. -Niemz P, Hofmann T. and Re´tfalvi, T., 2010. Investigation of chemical changes in the structure of thermally modified wood. MADERAS: Ciencia y Tecnologıa 12(2):69–78. -Noguchi, T., Obataya, E. and Ando, K., 2012. Effects of aging on the vibrational properties of wood. Journal of Cultural Heritage 13S: S21–S25. -Ngulia Irani, G., Petrissans, M. and Gerardin, P., 2007. Chemical reactivity of heat treated wood. Wood science Technology .41(2): 157-168D. -Roohnia, M., Doosthosseini, K., Khademieslam, H., Gril, J. and Bremaud, I., 2007. Study on variations of specific modulus of elasticity and shear moduli in arizona cypress wood. Using vibration method. Iranian Journal of Natural Resources. 59(4):921-933. -Roohnia, M., Tajdini, A. and Manouchehri, N., 2011. Assessing wood in sounding boards considering the ratio of acoustical anisotropy. NDT and E International., 44(1): 13-20. -Roohnia, M., Kohantorabi, M. and Tajvidi, A., 2015. Maple wood extraction for a better acoustical performance, Eur.J. wood production. 73(1), 139-142. -Sandberg, D., Haller, P. and Navi, P., 2013. Thermo-hydro and thermo-hydro-mechanical wood processing: an opportunity for future environmentally friendly wood products. Wood Mat Sci Eng 8:64–88 -Sha, T.O., 2015. On influences of high-temperature/ ultrasonic pretreatment on the vibration properties of metasequoia glyptostroboides, Master's Thesis, Beijing Forestry University, Beijing, China. -Se Golpayegani, A., Pourtahmasi, K., zare, S., Bremaud, I., Gril, J., Thévenon, M.F. and Masson, E., 2013. Basic acoustic properties and effect of traditional treatments.Morus alba for Tar instrument. Journal of Art Research. No 4: 71-76 -Tarmian, A. and Mastouri, A., 2019. Changes in moisture exclusion efficiency and crystallinity of thermally modified wood with aging. 12(1): 92-97. IForest. https://doi.org/10.3832/ifor2723-011 -Tjeerdsma, BF., Boonstra, M., Pizzi, A., Tekely, P. and Militz, H., 1998. Characterisation of thermally modified wood: molecular reasons for wood performance improvement. Holz Roh Werkst 56:149–153. -Wu, Y., Sha, T., Zhao, Z., He, Z. and Yi, S., 2016. Influence of different pretreatments on the acoustic properties of dawn redwood (Metasequoia glyptostroboides Hu et Cheng). BioResources.11 (1): 2734-2743. -Windeisen, E., Strobel, C. and Wegener, G., 2007. Chemical changes during the production of thermotreated beech wood. Wood Science and Technology 41(6): 523-536 -Yildiz, S., Gezer, ED. and Yildiz, UC., 2006. Mechanical and chemical behavior of spruce wood modified by heat. Build Environ 41:1762–1766. -Zaman, A., Alén, R. and Kotalinen, R., 2000. Thermal behavior of Scots pine (Pinus silvestris) and silver birch (Betula pubescens) at 200-230 oC. Wood and Fiber Science, 32(2): 138-143 -Zauer, M., Kowaleswki, A., Sproßmann, R., Stonjek, H. and Wagenführ, A., 2016. Thermal modification of European beech at relatively mild temperatures for the use in electric bass guitars. Eur J Wood Prod 74:43–48. -Zhu, L., Liu, Y. and Liu, ZH., 2016. Effect of high-temperature heat treatment on the acoustic-vibration performance of picea jezoensis. Bioresources 11(2): 4921-4934.
| ||
|
Statistics Article View: 746 PDF Download: 560 |
||
Journal management system. designed by sinaweb