Modification of water vapor diffusion in poplar wood (Populus nigra L.) by steaming at high temperatures


Abstract: In this investigation, the effect of steaming on the water vapor diffusion coefficient of poplar wood (Populus nigra L.) was studied. Boards with dimensions of 50 × 50 × 150 (W × H × L) mm3 and average moisture content of 12% were steamed at temperatures of 120, 140, 160, and 180 ^°C for 1, 2, and 3 h. The diffusion coefficients were then measured based on Fick's law of diffusion in steady-state conditions using the cup method. Results showed that the steaming of poplar wood at all mentioned temperatures can decrease the water vapor diffusion coefficient. However, no further improving effect was caused by increasing the steam temperature or duration. Some significant wood anatomical and chemical changes like cell wall collapse and holocellulose hydrolysis give some explanations for the improving effect of steaming on the diffusion coefficient. Overall, steaming at temperature of 120 ^°C for 1 h as the best treatment is recommended to modify the water vapor diffusion coefficient.

Keywords: Poplar wood, steaming, water vapor diffusion

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