Effects of Heat-Treatment in Hot Water and Steam Mediums on Gas Permeability of Beech Wood
H Reza Taghiyari, A Talaei, A Karimi
Heat-treatment, as a major method of wood modification, improving dimensional stability, and natural durability, has been studied greatly from different aspects. The effect of heat-treatment on gas permeability, as an important physical property of wood, in two different mediums of hot water and steam, as well as in two buffers of 7 and 8, is the main topic of the present study. Hydrothermal treatment made gas permeability decrease to its lowest value among the other treatments (91.6% decrease comparing control treatment). Hydrothermal treatment in buffer 8 made the lowest impact on gas permeability (12.3% decrease). Decrease in gas permeability value was due to settlement of extractives on vessel perforation plates. Gas permeability showed a high significant correlation (0.88) with the amount of swelling in radial direction; it may therefore be concluded that gas permeability may be considered a suitable criterion for predicting the amount of swelling.
Keywords: gas permeability, heat treatment, hydrothermal, hygrothermal, wood modification