コロナ放電処理効果におよぼす木材含水率の影響

Contact angle, volume of oontacted liquid and infrared spectrum of corona treated Apitong(Dipterocarpus grandiflorus BLANCO) oontaining 2.5 percent of alcohol-benzene extractives were measured to investigate the effect of moisture content on corona treatment efficiency. The degree of tretment used was 0.533kWmin/m^2 only.
The cosine contact angle on treated wood surface with water increased with an increase in the moisture content(MC) at discharging, and it reached a maximum. On that occasion, MC of wood at corona discharge was 12%. Same tendency was obtained with glycerin, phenol resorcinol formaldehyde resin(PRF) and urea formaldehyde resin(UF).
The volume of contacted liquids decreased with an increase in the time after the contact. Thus, the tendency of penetration was as same as that of the cosine contact angle.
The relationship between the infrared absorbance ratio(A_<1730>/A_<1500>) and MC was as same as that obtained by the cosine oontact angle. Therefor wettability of wood increased with surface oxidation by corona discharge treatment.
The dry strength glued with PRF increased with an increase in MC, but wet strength glued with PRF and dry and wet strength glued with UF were not affected with MC at discharging.