The Effect of Steaming Beech, Birch and Maple Woods on Qualitative Indicators of the Surface

This work presents the effect of steaming beech, birch and maple woods on the resulting quality of the milled wood surface. The steaming process of the studied woods results in a targeted change in the color of the wood, which changes from the original light white-gray color to fine reddish-brown to dark brown color shades that are more or less saturated depending on the temperature of the saturated water steam. The color changes achieved during the modification process were identified using coordinates in the CIE L*a*b* color space. The achieved color changes were described through the total color difference of ΔE* and defined through classification grades using a color scale. The technological process of wood steaming with saturated water steam for the purpose of a targeted change in the color of the wood and experimental measurements of the roughness of the milled wood surface proved that the wood steaming process has a positive effect on the roughness of the wood surface of the investigated trees, depending on the steaming temperature. The reduction of roughness in the process of the modification of beech wood compared with native wood was at the temperature of the saturated water steam as follows: tI = 105 ± 2.5 °C by Ra = 12.3%, at tII = 125 ± 2.5 °C by Ra = 15.4%, at tIII = 135 ± 2.5 °C by Ra = 16.9%. By modifying birch wood at tIII = 135 ± 2.5 °C, the roughness decreased by Ra = 13.4%; the surface roughness decreased by Ra = 15.8% compared with native wood by modifying maple wood. The roughness of the milled surface of modified wood in individual treatment modes decreased compared with native wood, which means that the milled surface of modified wood is of a better quality, which is positive for its practical use.