Comparative Study of Heat Treated Beech Wood in Hot Water and Steam Mediums

Heat treatment of wood is an effective method to improve the dimensional stability and durability against biodegradation. Heat treatments of beech wood in 2 different mediums (hot water and steam) at 180ºC were compared by physical، mechanical and anatomical properties. Mass loss in hydrothermally treated wood was higher than hygrothermally treated specimens. Mechanical properties (MOR and MOE) were decreased in both mediums، but strength loss was higher for hygrothermal treated samples. Anatomical changes were investigated by means of a light microscopic analysis. Beech was sensitive to collapse of the vessels in both mediums. In treated beech، radial cracks were observed near the rays both in hydro and hygrothermal treatments. Depletion of extractives on the cell walls and deformation of libriform fibers near the vessels were also observed.