Effect of Treatments of Microwave Radiation and Steaming on Color of Larch Wood
Larch wood (larix) contains plenty of resin and a combined treatment with microwave irradiation and subsequently steaming is a strategy to remove the resins in the larch wood. In this study, the effects of microwave power (5.54, 12.92, and 24 kW) and steaming period (2, 4, 6, 8, 12, and 16 h) on surface color were investigated. After air-drying, L*（Lightness）, Ag*(Hue Angle), and ΔE*( color difference) values of control increased, however, redness（a*）, yellowness（b*） and Chroma（C*）values decreased. The color parameters of larch wood after microwave treatment and air-drying exhibited a same trend as the control, but the values were slightly larger than the absolute value of control. Simultaneous, L* and ΔE* values also increased but b* and C* values decreased. Most a* values decreased, Ag* values decreased or unchanged. Treatment with microwave-steaming followed with air-drying caused an increase in L* and ΔE*; however, b* and C* values decreased. Steaming for 8h and 12h at 12.92kW resulted in increased a* values but the other parameters decreased. For steaming The Ag* values did not exhibit any trend due to steaming.
T. Jiang et al., "Effect of Treatments of Microwave Radiation and Steaming on Color of Larch Wood", Advanced Materials Research, Vol. 304, pp. 124-130, 2011