Establishing regularities in the propagation of phase transformation front during timber thermal modification

Authors

DOI:

https://doi.org/10.15587/1729-4061.2021.225310

Keywords:

thermally modified timber, modification efficiency, moisture absorption, diffusion, timber moisture resistance

Abstract

The creation of environmentally friendly protective materials for building structures made of wood could make it possible to influence the processes of stability and the physical-chemical properties at the thermal modification of hornbeam wood over a certain time. That necessitates studying the conditions for investigating phase transformations when the timber is exposed to high temperature, as well as establishing the mechanism of hornbeam wood thermal modification. Given this, a mathematical model of the phase transformation process during the transfer of heat flux to a sample was built. Based on the derived dependences, it was established that when hornbeam wood is exposed to temperature treatment, it undergoes endothermic phase transformations characterized by the heat absorption and change in the color of hornbeam wood. In particular, at a temperature of 200 °C, the temperature in the wood decreases by 5 % due to the chemical changes in the structure of cell wall components (lignin, cellulose, and hemicellulose). It was found that the process of thermal modification is accompanied by the decomposition of hemicellulose and the amorphous part of cellulose, a decrease in moisture absorption, as well as a decrease in the volume of substances that are a medium for the development of fungi. In addition, lignin and the resulting pseudo lignin undergo a process of polymerization and redistribution throughout the cell volume. At the same time, they give the cell walls higher density, hardness, increase hydrophobicity (water repellency), thereby reducing the ability to absorb moisture and swell. It was established that the most effective parameter of phase transformations is the temperature and aging duration. The results of moisture absorption have been given; it has been found that over 6 hours of modified timber exposure, its moisture absorption decreases by more than 10 times, which allows its application at facilities with high humidity

Author Biographies

Yuriy Tsapko, National University of Life and Environmental Sciences of Ukraine; Kyiv National University of Construction and Architecture

Doctor of Technical Sciences

V. D. Glukhovsky Scientific Research Institute for Binders and Materials

Oleksandra Horbachova , National University of Life and Environmental Sciences of Ukraine

PhD

Department of Technology and Design of Wood Products

Аleksii Tsapko , Ukrainian State Research Institute "Resurs"

Senior Research Fellow

Department of Research on Quality and Storage Conditions of Petroleum Products and an Industrial Group of Goods

Serhii Mazurchuk , National University of Life and Environmental Sciences of Ukraine

PhD

Department of Technology and Design of Wood Products

Denys Zavialov , National University of Life and Environmental Sciences of Ukraine

Assistant

Department of Technology and Design of Wood Products

Nataliia Buiskykh , National University of Life and Environmental Sciences of Ukraine

PhD

Department of Technology and Design of Wood Products

References

  1. Tsapko, Y., Tsapko, А., Bondarenko, O. (2019). Effect of a flame­retardant coating on the burning parameters of wood samples. Eastern-European Journal of Enterprise Technologies, 2 (10 (98)), 49–54. doi: http://doi.org/10.15587/1729-4061.2019.163591
  2. Tsapko, Y., Lomaha, V., Bondarenko, O. P., Sukhanevych, M. (2020). Research of Mechanism of Fire Protection with Wood Lacquer. Materials Science Forum, 1006, 32–40. doi: http://doi.org/10.4028/www.scientific.net/msf.1006.32
  3. Tsapko, Y., Lomaha, V., Tsapko, А., Mazurchuk, S., Horbachova, O., Zavialov, D. (2020). Determination of regularities of heat resistance under flame action on wood wall with fire-retardant varnish. Eastern-European Journal of Enterprise Technologies, 4 (10 (106)), 55–60. doi: http://doi.org/10.15587/1729-4061.2020.210009
  4. Esteves, B. M., Pereira, H. M. (2008). Wood modification by heat treatment: A review. BioResources, 4 (1), 370–404. doi: http://doi.org/10.15376/biores.4.1.370-404
  5. Humar, M., Lesar, B., Kržišnik, D. (2020). Moisture Performance of Façade Elements Made of Thermally Modified Norway Spruce Wood. Forests, 11 (3), 348. doi: http://doi.org/10.3390/f11030348
  6. Humar, M., Repič, R., Kržišnik, D., Lesar, B., Cerc Korošec, R., Brischke, C. et. al. (2020). Quality Control of Thermally Modified Timber Using Dynamic Vapor Sorption (DVS) Analysis. Forests, 11 (6), 666. doi: http://doi.org/10.3390/f11060666
  7. Sandberg, D., Kutnar, A., Mantanis, G. (2017). Wood modification technologies – a review. iForest – Biogeosciences and Forestry, 10 (6), 895–908. doi: http://doi.org/10.3832/ifor2380-010
  8. Aytin, A., Korkut, S. (2015). Effect of thermal treatment on the swelling and surface roughness of common alder and wych elm wood. Journal of Forestry Research, 27 (1), 225–229. doi: http://doi.org/10.1007/s11676-015-0136-7
  9. Pelosi, C., Agresti, G., Lanteri, L., Picchio, R., Gennari, E., Lo Monaco, A. (2020). Artificial Weathering Effect on Surface of Heat-Treated Wood of Ayous (Triplochiton scleroxylon K. Shum). The 1st International Electronic Conference on Forests (IECF). Available at: https://www.researchgate.net/publication/345761222_Artificial_Weathering_Effect_on_Surface_of_Heat-Treated_Wood_of_Ayous_Triplochiton_scleroxylon_K_Shum
  10. Ugovšek, A., Šubic, B., Rep, G., Humar, M., Lesar, B., Thaler, N., Brischke, C. et. al. (2016). Performance of Windows and façade elements made of thermally modified Norway spruce (Picea abies). in different climatic conditions. Proceedings of the WCTE 2016-World Conference on Timber Engineering, Vienna, 9.
  11. Ugovšek, A., Šubic, B., Starman, J., Rep, G., Humar, M., Lesar, B. et. al. (2018). Short-term performance of wooden windows and facade elements made of thermally modified and non-modified Norway spruce in different natural environments. Wood Material Science & Engineering, 14 (1), 42–47. doi: http://doi.org/10.1080/17480272.2018.1494627
  12. Bonifazi, G., Serranti, S., Capobianco, G., Agresti, G., Calienno, L., Picchio, R. et. al. (2016). Hyperspectral imaging as a technique for investigating the effect of consolidating materials on wood. Journal of Electronic Imaging, 26 (1), 011003. doi: http://doi.org/10.1117/1.jei.26.1.011003
  13. Jones, D., Sandberg, D., Goli, G., Todaro, L. (2019). Wood Modification in Europe: a state-of-the-art about processes, products and applications. Firenze University Press, 123. doi: http://doi.org/10.36253/978-88-6453-970-6
  14. Janna, W. S. (2010). Engineering Heat Transfer. Boca Raton: CRC Press, 692.
  15. Potter, M. C. (2018). Engineering analysis. New York: Springer, 444.
  16. Temme, N. M. (1996). Special Functions: An Introduction to the Classical Functions of Mathematical Physics. Mathematics & Statistics. Applied Mathematics, 392. doi: http://doi.org/10.1002/9781118032572

Downloads

Published

2021-02-23

How to Cite

Tsapko, Y., Horbachova , O., Tsapko А., Mazurchuk , S., Zavialov , D. ., & Buiskykh , N. (2021). Establishing regularities in the propagation of phase transformation front during timber thermal modification . Eastern-European Journal of Enterprise Technologies, 1(10 (109), 30–36. https://doi.org/10.15587/1729-4061.2021.225310