Evaluation of dimensional stability, surface roughness, colour, flexural properties and decay resistance of thermally modified Acacia auriculiformis


  • S.R. Shukla


Density, heat treatment, MOR, MOE, plantation species, shrinkage


This paper presents the effect of thermal modification of 14-15 year-old plantation grown Acacia auriculiformis wood in the 150-240ºC temperature range under vacuum condition. Important techno-mechanical parameters of thermally modified wood such as density, dimensional stability, colour, surface roughness, decay resistance against brown and white rot fungi and flexural properties were evaluated and compared with control. Depending on severity of heat treatment, colour of modified sapwood was turned from light to dark brownish. Moreover, the change in colour was found to be uniform throughout the thickness of wood blocks. Amount of shrinkage of Acacia auriculiformis wood was observed to be decreased with increasing treatment temperatures. Maximum dimensional stability of wood thermally modified at 240ºC was in the range of 60-65%. The surface roughness parameters (Ra and Rz) were reduced significantly after the treatment. The flexural strength (modulus of rupture-MOR) was observed to be reduced with increasing treatment temperatures. However, flexural stiffness (modulus of elasticity-MOE) was not found to be affected significantly up to 210ºC temperature. The lower amount of weight loss of thermally modified wood compared to untreated control showed improved decay resistance against white and brown rot fungi. With desirable improvements in various esthetic and technologically important quality parameters such as enhanced dimensional stability, biological durability against fungi and certain other properties, thermally modified wood from short-rotation Acacia auriculiformis may be considered as viable alternative to scarcely available timber resource for different value-added applications.


Download data is not yet available.


Anon. 1986. IS:1708. Indian standard for ‘Methods of testing small clear specimens’. Bureau of Indian Standards, New Delhi

Anon. 2008. IS:4873. Indian standards for 'Methods of laboratory testing of wood preservatives against fungi and borers (powder post beetles). Part 1:
Determination of threshold values of wood preservatives against fungi. Bureau of Indian Standards, New Delhi

Anon. 2012. Mitutoyo surface roughness tester-Mitutoyo Surftest SJ-401. Mitutoyo Corporation, 20-1, Sakado 1-chome, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan

Ashaduzzaman, M.; Das, A.K.; Kayes I.; Shams, M.I. 2011. Natural decay resistance of Acacia auriculiformis Cunn. ex. Benth and Dalbergia sissoo Roxb. Bangladesh Journal of Science and Industrial Research 46(2): 225-230.

Bakar, B.F.A.; Hiziroglu, S.; Tahir, P Md. 2013. Properties of some thermally modified wood species. Materials and Design 43 348-355.

Chu, T.V. 2013. Improvement of dimensional stability of Acacia mangium wood by heat treatment: a case study of Vietnam. Journal of Forest Science 29(2):109-115.

Emmler, R.; Scheiding, W. 2007. Darker shades of wood: Thermally modified timber (TMT) as a new material for parquet floorings. European Coatings Journal, April Issue: 106-111.

Esteves, B.M.; Pereira, H.M. 2009. Wood modification by heat treatment: a review BioResources 4(1): 370-404.

Gerardin, P. 2016. New alternatives for wood preservation based on thermal and chemical modification of wood-a review. Annals of Forest Science 73:559–570.

Gunduz, G.; Korkut, S.; Korkut, D.S. 2008. The effects of heat treatment on physical and technological properties and surface roughness of Camiyanı Black Pine (Pinus nigra Arn. subsp. pallasiana var. pallasiana) wood. Biores Technol 99:2275–2280.

Hill, C.A.S. 2006. Wood modification- chemical, thermal and other processes. John Wiley & Sons, Chichester. pp 239.

Hofmann, T.; Retfalvi, T.; Albert, L.; Niemz, P. 2008. Investigation of the chemical changes in the structure of wood thermally modified within a nitrogen atmosphere autoclave. Wood Research 53 (3):1-14.

Kamdem, D.P.; Pizzi, A.; Jermanaud, A. 2002. Durability of heat-treated wood. Holz Roh Werkstoff 60 (1):1-6.

Kamdem, D.P.; Pizzi, A.; Triboulot, M.C. 2000. Heat-treated timber: potentially toxic byproducts presence and extent of wood cell wall degradation. Holz Roh- Werkstoff 58(4):253-257.

Kim, G.H.; Yun, K.E.; Kim, J.J.1998. Effect of heat treatment on the decay resistance and the bending properties of radiata pine sapwood. Mater Organismen 32(2):101-108.

Kubojima, Y.; Okano, T.; Ohta, M. 2000. Bending strength and toughness of heat-treated wood. Journal Wood Science 46(1):8-15.

Metsa-Kortelainen, S.; Antikainen, T.; Viitaniemi, P. 2006. The water absorption of sapwood and heartwood of Scots pine and Norway spruce heat-treated at 170ºC, 190ºC, 210ºC and 230ºC. Holz Roh- Werkstoff 64:192-197.

Metsa-Kortelainen, S.; Viitanen, H. 2010. Effect of fungal exposure on the strength of thermally modified Norway spruce and Scots pine. Wood Mat Science and Engineering:13-23.

Nakano, T.; Miyazaki, J. 2003. Surface fractal dimensionality and hygroscopicity for heated wood. Holzforschung 57: 289-294.

Niemz, P.; Bekhta, P. 2003. Effect of high temperature on the changes in color, dimensional stability and mechanical properties of spruce wood. Holzforschung 57(5): 539-546 .

Niemz, P.; Hofmann, T.; Retfalvi, T. 2010. Investigation of chemical changes in the structure of thermally modified wood. Maderas-Ciencia Y Tecnologia 12(2):69-78.

Obataya, E.; Tanaka, F.; Norimoto, M.; Tomita, B. 2000. Hygroscopicity of heat-treated wood I: Effects of after-treatments on the hygroscopicity of heat-treated wood. Mokuzai Gakkaishi 46(2):77-87.

Obataya, E.; Tomita, B. 2002. Hygroscopicity of heat-treated wood. II Reversible and irreversible reductions in the hygroscopicity of wood due to heating. Mokuzai Gakkaishi 48(4):288-295.

Pfriem, A.; Wagenfuhr, A. 2007. Influence of thermally modification of spruce to unsteady-state sorption processes and wood moisture-dependent elasticity. In: Proc 3rd European Conference on Wood Modification, 15th-16th Oct, Cardiff, UK pp367-373.

Rep, G.; Pohleven, F. 2001. Wood modification–a promising method for wood preservation. Drvna Industrija 52 (2): 71-76.

Repellin, V.; Guyonnet, R. 2005. Evaluation of heat-treated wood swelling by differential scanning calorimetry in relation to chemical composition. Holzforschung 59:28–34.

Shukla, S.R.; Rao, R.V.; Sharma, S.K.; Kumar, P.; Sudheendra, R.; Shashikala, S. 2007. Physical and mechanical properties of plantation grown Acacia auriculiformis of different ages. Australian Journal of Forestry 70 (2):86-92.

Shukla, S.R.; Sharma, S.K. 2014. Effect of high temperature processing under different environments on physical and surface properties of Rubberwood (Hevea brasiliensis). Journal of Indian Academy of Wood Science 11(2): 182-189.

Shukla, S.R.; Sharma, S.K. 2018. Effect of high temperature treatment of Hevea brasiliensis on density, strength properties and resistance to fungal decay. Journal of Indian Academy of Wood Science 15(1): 87-95.

Sundararaj, R.; Shanbhag, R.R.; Nagaveni, H.C.; Vijayalakshmi, G. 2015. Natural durability of timbers under Indian environmental conditions- An overview. International Biodeterioration & Biodegradation 103:196-214.

Tjeerdsma, B.F.; Militz, H. 2005. Chemical changes in hydrothermal treated wood: FTIR analysis of combined hydrothermal and dry heat-treated wood. European Journal of Wood and Wood Products 63(2):102-111.

Wahab, R.; Khalid, I.; Tabet, T.A.; Mohamed, A.; Sulaiman, O.; Salim, R.Md.; Ayob, F.W. 2012. Effectiveness of hot oil treatment on cultivated 15 year-old Acacia hybrid against Coriolus versicolors, Gloeophyllum trabeum and Pycnoporus sanguineus. Sains Malaysiana 41(2):163-169.

Wikberg, H.; Liisa, M.S. 2004. Characterisation of thermally modified hard- and softwoods by 13C CPMAS NMR. Carbohydrate. Polymers 58: 461-466.

Windeisen, E.; Bächle, H.; Zimmer, B.; Wegener, G. 2009. Relations between chemical changes and mechanical properties of thermally treated wood. Holzforschung 63(6): 773-778.

Windeisen, E.; Strobel, C.; Wegener, G. 2007. Chemical changes during the production of thermo-treated beech wood. Wood Science and Technology 41(6):523-536.

Windeisen, E.; Wegener, G. 2008. Behaviour of lignin during thermal treatments of wood. Industrial Crops and Products 27(2):157-162.




How to Cite

Shukla, S. (2019). Evaluation of dimensional stability, surface roughness, colour, flexural properties and decay resistance of thermally modified Acacia auriculiformis. Maderas-Cienc Tecnol, 21(4), 433–446. Retrieved from https://revistas.ubiobio.cl/index.php/MCT/article/view/3639