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

Abstract

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.

11th Hardwood Conference Proceedings

“…It was similarly found in the b * -L * or a * -L * space (Figures 1c, and 1d). The results were similar to that achieved by Dudiak et al (2024). Analysis of variance and Duncan's test at the 0.05 significance level specified which colour coordinates of heat-treated woods were similar to tropical woods (Table 3).…”

“…At the end of treatment, samples were cooled down in desiccators in dry environment. The other samples were hydrothermally treated with saturated water steam temperature 135 ± 2.5 °C for six hours as was described in Dudiak et al (2024). Selected tropical woodsipé (Handroanthus serratifolius), iroko (Milicia excelsa), maçaranduba (Manilkara bidentata), makoré (Tieghemella heckelii), sapelli (Entandrophragma cylindricum) and wengé (Millettia laurentii) in a form of naturally dried and conditioned boards in temperature 22 ± 2.5 °C and relative humidity 65% in climatic camber.…”

The Effect of the Beech Wood Steaming Condensate on Curing Behaviour of Urea-formaldehyde Adhesive

“…This physico-chemical process characterized by elevated temperatures, a steam atmosphere, high wood moisture content, and the presence of microorganisms, initiates the chemical reactions in wood: degradation processes of primary wood components, cellulose, hemicellulose, and lignin followed by the extraction of water-soluble substances into the wastewater solution (Dzurenda et al 2022). While steaming is usually employed to equalize (or change) the colour of wood, it also offers bene ts such as growth stress reduction (Gril et al 2017), reduced initial moisture content and moisture content gradient (Fu et al 2019), improved drying characteristics (Milić et al 2015), increased dimensional stability (Fruhwald 2006) and reduced surface roughness (Dudiak et al 2024). For beech timber -one of the most important hardwood species in Europe -steaming is pivotal in enhancing the aesthetic appeal and market value of wood products.…”