THE EFFECT OF SUNLIGHT ON THE COLOR CHANGE OF STEAMED BIRCH WOOD
Keywords:
birch wood, saturated water steam, natural aging, wood color, steamingAbstract
The differences in color changes of native and steamed birch wood saturated with water steam at a temperature of t = 135 °C for a period of τ = 7.5 hours caused by the long-term exposure of sunlight to the surface of the wood in interiors for 48 months are presented in the paper. The deep brown-red color of the steamed birch wood lightened and acquired a brown shade due to the UV components of sunlight during the 48-month exposure. The degree of lightening of the color of steamed birch wood in the color space CIE L*a*b* is quantified by an increase in the values of the lightness coordinate from L0* = 59.8 to L48* = 66.5 and the yellow color chromatic coordinate from b0* = 19.2 to b48* = 24.0. On the contrary, the light white-brown color of the native birch wood darkened due to the effect of the UV components of sunlight and acquired a brown-pink color with a yellow tint. The degree of darkening and browning is quantified by a decrease in the values on the lightness coordinate from L0* = 81.1 to L48* = 68.2 and an increase in the values on the chromatic coordinates: red color a0* = 7.2 to a48* = 13.1 and yellow color from b0* = 20.0 to b48* = 25.9. The comparison of the color changes of native and steamed birch wood through the total color difference ∆E* under the influence of daily sunlight shows that the surface of steamed wood shows 45.8% smaller changes than native wood. The lower value of the total color difference of steamed wood points to the fact that steaming wood with saturated water steam has a positive effect on color stability and partial resistance to the initiation of photolytic reactions caused by UV + VIS wavelengths of sunlight.
References
Baar, J., Gryc, V., 2011. The analysis of tropical wood discoloration caused by simulated sunlight. Europen Journal of wood and Wood Products 70(1-3), 263-269.
Babiak, M., Kubovský, I., Mamoňová, M., 2004. Color space of selected local woods. Interaction of wood with various forms of energy. Technical University in Zvolen. 113-117.
Denes, L., Lang, E.M., 2013. Photodegradation of heat-treated hardwood veneers. Journal of Photochemistry and Photobiology B: Biology 118: 9-15.
Dudiak, M., 2022. The effect of sunlight on the change in color of native and steamed maple wood with saturated water steam. Acta facultatis xylologiae Zvolen, 64 (1): 59 – 68.
Dudiak, M., Dzurenda, L., Kučerová, V., 2022. Effect of Sunlight on The Change in Color of Unsteamed and Steamed Beech Wood with Water Steam. Polymers 14. 1697.
Dzurenda, L., 2018. Colour modification of Robinia pseudoacacia L. during the processes of heat treatment with saturated water steam. Acta facultatis xylologiae Zvolen, 60 (1):61 – 70.
Dzurenda, L., 2021. Mode for hot air drying of alder blanks that retain the color acquired during the steaming process. Annals of Warsaw University of Life Sciences. Forestry and Wood Technology 114, 86-92.
Dzurenda, L., Dudiak, M., Výbohová E., 2022: Influence of UV Radiation on the Color Change of the Surface of Steamed Maple Wood with Saturated Water Steam. Polymers 14 (1): 217.
Gandelová, L., Horáček., P., Šlezingerová, J., 2009. The science of wood. Mendel University of Agriculture and Forestry in Brno. 176 p.
Geffertová, J., Geffert, A., Vybohová, E., 2018. The effect of UV irradiation on the colour change of the spruce wood. Acta Facultatis Xylologiae Zvolen 60(1), 41-50.
Hon D.S.N., 2001. Weathering and photochemistry in wood. Hon D.S.N., Shiraishi, N. Wood and cellulosic chemistry. 2nd edition. New York: Marcel Dekker, 513-546.
Hrvoľ, J., Tomlain, J., 1997. Radiation in the atmosphere. 1ed. Bratislava, Comenius University in Bratislava. 136 p.
Chang, T. C., Chang H. T., Chang S. T., 2010. Influences of extractives on the photodegradation of wood. Polymer Degradation and Stability, 95: 516-521.
Kúdela, J., Kubovský, I., 2016. Accelerated-ageing-induced photo-degradation of beech wood surface treated with selected coating materials. Acta Facultatis Xylologiae Zvolen 58(2). 27-36.
Liu, R., Zhu, H., Li, K., Yang, Z., 2019. Comparison on the Aging of Woods Exposed to Natural Sunlight and Artificial Xenon Light. Polymers, 11, 709.
Meints, T., Teischinger, A., Stingl, R., Hansmann, C., 2017. Wood colour of central European wood species: CIELAB characterisation and colour intensification, Eur. J. Wood Prod. 75: 499-509.
Makovíny, I., 2010. Useful properties and use of different types of wood. Technical University in Zvolen, 2010, 104 p.
Persze, L., Tolvaj, L., 2012. Photodegradation of wood at elevated temperature: Colour change. Journal of Photochemistry and Photobiology B: Biology 108, 44-47.
Reinprecht, L. 2008., Wood protection. Technical University in Zvolen, 450 p.
Tolvaj, L., Nemeth, R., Varga, D., Molnar, S., 2009. Colour homogenisation of beech wood by steam treatment. In: Drewno. No. 52 vol. 181. s. 5 – 17.
Varga, D., Tolvaj, L., Molnar, Z., Pasztory, Z., 2020. Leaching efect of water on photodegraded hardwood species monitored by IR spectroscopy. Wood Science and Technology 54, 1407–1421.
