Needle fir wood modified by surface densification and thermal post-treatment: hygroscopicity and swelling behavior
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Needle fir (Abies nephrolepis) wood was surface densified at two compression ratios (16.1 and 21.7 %), two hot-pressing temperatures (160 and 180 °C) for a pressure holding duration of 10 min. Subsequently, it was thermally treated at two temperatures (180 and 200 °C) for 1 h. The equilibrium moisture content responses and radial swelling strain ratios were calculated for thirteen types of adsorption specimens under adsorption and water soaking, respectively. Compared with untreated (control) specimens and densified but non-thermally treated ones, the hygroscopicity of thermally post-treated specimens was significantly decreased. Both hot-pressing temperature and compression ratio showed insignificant influence on the hygroscopicity of all treated specimens. Under the current test conditions, with the increase of thermal post-treatment temperature and the decrease of compression ratio among the thermally post-treated specimens, the radial swelling deformation was significantly decreased. The impact of increasing hot-pressing temperature on the radial swelling was insignificant according to the statistical analysis.
KeywordsCompression Ratio Densified Wood Dimensional Stability Equilibrium Moisture Content Surface Densification
This research was financially supported by the Fundamental Research Funds for the Central Universities of China (Northeast Forestry University, No. DL13CB17).
- Cai JB, Ding T, Yang L, Yang X (2012) Effect of heat treatment and densification on dimension stability of Poplar wood (in Chinese). China Wood Ind 26(5):41–44Google Scholar
- Tu DY, Wang MJ, Gu LB et al (2010) Effect of super high temperature heat treatment on Fraxinus mandshurica board’s dimension stability (in Chinese). J Nanjing Forest Univ (Natural Science Edition) 34(3):113–116Google Scholar
- Zhan JF, Gu JY, Cai YC (2009) Dynamic visco-elastic characteristics of larch timber during conventional drying process (in Chinese). J Beijing Forest Univ 31(1):129–134Google Scholar
- Zhan JF, Cao J, Gu JY et al (2015) Surface-densification and high-temperature hydrothermal post treatment of the Abies nephrolepis lumber (in Chinese). J Nanjing Forest Univ (Natural Science Edition) 39(3):119–124Google Scholar