Dynamic moisture sorption and hygroexpansion of Populus euramericana Cv. under two cyclic hygrothermal conditions

作者：Yang, Tiantian; Ma, Erni^*; Zhang, Jianhui

来源：Holzforschung, 2016, 70(12): 1191-1199.

DOI：10.1515/hf-2016-0015

• hygroexpansion
• moisture sorption
• sinusoidal RH changes
• sinusoidal temperature changes
• wood

Poplar (Populus euramericana Cv.) specimens, 20 mm in radial (r) and tangential (t) directions with thicknesses of 4 mm and 10 mm along the longitudinal direction, were subjected to cyclic environmental conditions, in the course of which the relative humidity (RH) changed sinusoidally between 75% and 45% at 20 degrees C (condition A), or the temperature (T) was changed sinusoidally within 5-35 degrees C at 60% RH (condition B). Moisture content (MC), as well as the t-and r-dimensional changes were measured as a response to the dynamic environmental conditions. The measured data also changed sinusoidally but they lagged behind the triggering original RH or T data. This effect was much higher under condition A than under condition B. The observed equivalent RH and T changes at different Delta MCs or Delta ts served for comparison of the responses to RH and T, and the former were less pronounced than the latter. MC and t-dimensional changes per unit change of RH were greater than those per unit change of T but still lower than static values. In summary, the effects of dynamic RH change are larger than those of T, especially concerning MC responses compared to dimensional changes.

• 出版日期2016-12
• 单位北京林业大学