DOI QR코드

DOI QR Code

Dimensional Responses of Wood Under Cyclical Changing Temperature at Constant Relative Humidity

  • Yang, Tiantian (College of Materials Science and Technology, Beijing Forestry University) ;
  • Ma, Erni (College of Materials Science and Technology, Beijing Forestry University) ;
  • Shi, Yi (College of Materials Science and Technology, Beijing Forestry University)
  • Received : 2015.03.23
  • Accepted : 2015.06.22
  • Published : 2015.09.25

Abstract

To investigate dimensional responses of wood under dynamic temperature condition, poplar (populous euramericana Cv.) specimens, 20 mm in radial (R) and tangential (T) directions with two thicknesses of 4 and 10 mm along the grain, were exposed to cyclic temperature changes in square wave between $25^{\circ}C$ and $40^{\circ}C$ at 60% relative humidity (RH) for three different cycling periods of 6 h, 12 h and 24 h. R and T dimensional changes measured during the cycling gave the following results: 1) Transverse dimensional changes of the specimens were generally square but at an opposite phase and lagged behind the imposed temperature changes. The phase lag was inversely correlated with cycling period, but positively related to specimen thickness, while the response amplitude was directly proportional to cycling period, but in a negative correlation with specimen thickness. 2) The specimens showed swelling hysteresis behavior. The heat shrinkage coefficient (HSC) became greater as cycling period increased or specimen thickness decreased. 3) Dimensional changes of the specimens produced deformation accumulation during repeated adsorption and desorption. The deformation accumulating ratio decreased with an increase in cycling period and specimen thickness. 4) Wood suffered 1.5 times as many dimensional changes per unit temperature variation as per unit humidity variation, and this deformation behaved even more seriously under static condition.

Keywords

References

  1. Cao, J.Z., Zhao, G.J., Lu, Z.Y. 1997. Thermodynamic Characteristics of Water Absorption of Heat-treated Wood. Journal of Beijing Forestry University 19(4): 26-33.
  2. Chang, Y., Han, Y., Eom, C., Park, J., Park, M., Choi, I., Yeo, H. 2012. Analysis of factors affecting the hygroscopic performance of thermally treated Pinus koraiensis wood. Journal of the Korean Wood Science and Technology 40(1): 10-18. https://doi.org/10.5658/WOOD.2012.40.1.10
  3. Chomcharn, A., Skaar, C. 1983. Moisture and transverse dimensional changes during air drying of small green hardwood wafers. Wood Science Technology 17(3): 227-240. https://doi.org/10.1007/BF00372321
  4. Engelund, E.T., Thygesen, L.G., Svensson, S., Hill, C. A. S. 2013. A critical discussion of the physics of wood-water interactions. Wood Science Technology 47: 141-161. https://doi.org/10.1007/s00226-012-0514-7
  5. Espenas, L.D. 1971. Shrinkage of Douglas fir, western hemlock, and red alder as affected by drying conditions. Forest Products Journal 21(6): 44-46.
  6. Gao, R.T., Xu, Q.G., Su, W. 1995. Study on mechanism of wood thermal expansion. Journal of Northeast Forestry University 23(2): 55-61.
  7. Gong, R. M., Shen, J., He, L. Z., Liu, Y. L., Xu, L. Y. 2001. The effect of temperature on moisture movement and microstructure of larch wood in man-made forest. Journal of Northeast Forestry University 29(5): 31-33.
  8. Koji, M., Yasuhiro, W., Takato, N. 2013. Effect of Thermal Treatment on Fracture Properties and Adsorption Properties of Spruce Wood. Materials 6: 4186-4197. https://doi.org/10.3390/ma6094186
  9. Kollmann, F.F.P. 1959. Uber die Sorption von Holz und ihre exakte Bestimmung. Holz Roh- Werkst 17: 165-171. https://doi.org/10.1007/BF02608808
  10. Liu, Y.X., Zhao, G.J. 2004. Wood resources in Materials Science. Beijing, China.
  11. Macromolecule Academy. 1958. Physical properties of macromolecule. Tokyo, Japan.
  12. Ma, E.N., Nakao, T., Zhao, G.J., Ohata, H., Kawamura, S. 2010. Dynamic sorption and hygroexpansion of wood subjected to cyclic relative humidity changes. Wood Fiber Science 42(2): 229-236.
  13. Ma, E.N., Zhao, G.J. 2012. Special topics on wood physics. Beijing, China.
  14. Mcmillen, J.M. 1955. Drying stresses in red oak: effect of temperature. Forest Products Journal 5(4): 230-241.
  15. Murata, K., Watanabe, Y., Nakano, T. 2013. Effect of thermal treatment of veneer on formaldehyde emission of poplar plywood. Materials 6: 410-420. https://doi.org/10.3390/ma6020410
  16. Park, Y., Chang, Y., Yang, S., Yeo, H., Lee, M., Eom, C., Kwon, O. 2015. Wood shrinkage measurement of using a flatbed scanner. Journal of the Korean Wood Science and Technology 43(1): 43-51. https://doi.org/10.5658/WOOD.2015.43.1.43
  17. Park, Y., Han, Y., Park, J., Chang, Y., Yang, S., Chung, H., Kim, K., Yeo, H. 2015. Evaluation of physico-mechanical properties and durability of Larix kaempferi wood heat-treated by hot air. Journal of the Korean Wood Science and Technology 43(3): 334-343. https://doi.org/10.5658/WOOD.2015.43.3.334
  18. Rasmussen, E.F. 1961. Dry kiln operators handbook. Washington, DC, U.S.
  19. Oh, S.W., Park, H.J. 2015. Vacuum pressure treatment of water-soluble melamine resin impregnation for improvement of dimensional stability on softwoods. Journal of the Korean Wood Science and Technology 43(3): 327-333. https://doi.org/10.5658/WOOD.2015.43.3.327
  20. Stamm, A.J., Loughborough, W.K. 1935. Thermodynamics of the swelling of wood. Journal of Physical Chemistry 39: 121-132.
  21. Stevens, W.C. 1963. The transverse shrinkage of wood. Forest Products Journal 13(9): 386-389.
  22. Yang, T.T., Ma, E.N. 2015. Dynamic sorption and hygroexpansion of wood subjected to cyclic relative humidity changes II Effect of temperature. Bioresources 10(1): 1675-1685.
  23. Sonderegger, W., Niemz, P. 2006. Untersuchungen zur Quellung und Warrmedehnung von Faser-, Span- und Sperrholzplatten. Holz als Roh- und Werkstoff 64: 11-20. https://doi.org/10.1007/s00107-005-0043-2
  24. Unsal, O., Candan, Z., Buyuksari, U., Korkut, S., Chang, Y., Yeo, H. 2011. Effect of thermal compression treatment on the surface hardness, vertical density profile and thickness swelling of Eucalyptus wood boards by hot-pressing. Journal of the Korean Wood Science and Technology 39(2): 148-155. https://doi.org/10.5658/WOOD.2011.39.2.148
  25. Wang, J.Y., Zhao, G.J. 1999. Mechanism of formation, recovery and permanent fixation of wood set. Journal of Beijing Forestry University 21(3): 71-77.
  26. Weichert, L. 1963. Investigations on sorption and swelling of spruce, beech and compressed beech wood at temperatures between $20^{\circ}C$ and $100^{\circ}C$. Holz Roh Werkst 21(8): 290-300. https://doi.org/10.1007/BF02610962
  27. Xu, Y.M. 2006. Science of Wood. Beijing, China.
  28. Yang, T.T., Ma, E.N. 2013. Dynamic sorption and hygroexpansion of wood by humidity cyclically changing effect. Journal of Functional Materials 23(44): 3055-3059.
  29. Zhang, W.B., Morihiko, T., Takashi, T., Koh, Y. 2006. Effect of Delignifying Treatments on Mechano-sorptive Creep of Wood I. Journal of Wood science 52: 19-28.

Cited by

  1. Comparison of dynamic sorption and hygroexpansion of wood by different cyclic hygrothermal changing effects II vol.41, pp.4, 2018, https://doi.org/10.1177/1744259117708353