COLOUR CHARACTERISTICS OF PINE WOOD AFFECTED BY THERMAL COMPRESSING

Atik, Celil; Candan, Zeki; Unsal, Oner

doi:10.5902/198050989291

ABSTRACT

The goal of this study was to determine the effects of thermal modification and hot-pressing on the colour characteristics of pine wood as bio-resource. The experimental wood boards with dimensions of 250 mm in width by 500 mm in length by 18 mm in thickness were thermally compressed at a temperature of 120 ºC or 150 ºC, press pressure of 5 or 7 MPa for 60 min in a hot press. Results obtained in this study showed that the colour characteristics of the pine wood boards were affected by press pressure and temperature. The resin leakages significantly increased the chromacity (a* - 25.99 and b* - 43.18) of the treated wood samples. Thermally compressing caused browning of wood colour, which rate increases with pressure at high temperature conditions.

Keywords:
heat treatment; thermal compressing; pine wood; wood colour

RESUMO

O objetivo deste estudo foi determinar os efeitos das modificações térmicas e prensagem a quente sobre as características de cor de madeira de pinus como bio-recursos. As tábuas de madeira com dimensões de 250 mm de largura por 500 mm de comprimento por 18 mm de espessura foram comprimidas termicamente a uma temperatura de 120 ºC ou 150 ºC, a pressão de 5 ou 7 MPa durante 60 min em uma prensa quente. Os resultados obtidos neste estudo mostraram que as características de cor das amostras de madeira de pinus foram afetadas pela pressão e temperatura da prensa. A exsudação da resina aumentou significativamente as coordenadas cromáticas (a * - b * e 25,99 - 43,18) das amostras de madeira tratada. Compressão térmica causa escurecimento na cor da madeira, o que aumenta em condições de pressão e alta temperatura.

Palavras-chave:
tratamento térmico; compressão térmica; madeira de pinus; cor da madeira

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

REFERENCES

ATIK, C. Effect of sample position on colour values of wood under diffuse illumination. Rev. of the Faculty of Forestry, Istanbul, v. 56, n. 1, p. 73-79. 2006.
AYADI, N. et al. Colour stability of heat-treated wood during artificial weathering. Holz als Rohund Werkst, v. 61, p. 221-226. 2003.
AYDIN, I.; COLAKOGLU, G. Effects of surface inactivation, high temperature drying and preservative treatment on surface roughness and colour of alder and beech wood. Appl. Surf. Sci., v. 252, p. 430-440. 2005.
BEKHTA, P.; NIEMZ, P. Effect of high temperature on the change in colour, dimensional stability and mechanical properties of spruce wood. Holzforsch, v. 57, p. 539-546. 2003.
BLOMBERG, J. et al. Effects of semi-isostatic densification of wood on the variation in strength properties with density. Wood Sci. Tech., v. 39, p. 339-350. 2005.
BOURGOIS, P.J. et al. The colour measurement: a fast method to study and to optimize the chemical transformations undergone in the thermically treated wood. Holzforsch , v. 45, p. 377-382. 1991.
ESTEVES, B. et al. Heat-induced colour changes of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) wood. Wood Sci. Tech., v. 42, p. 369-384. 2008.
KUBOJIMA, Y. et al. Effect of shear deflection on bending properties of compressed wood. Wood Fiber Sci., v. 36, p. 210-215. 2003.
MONNONEN, K. et al. CIEL*a*b* Measurements to Determine the Role of Felling Season, Log Storage and Kiln Drying on Colouration of Silver Birch Wood. Scandinavian. J. For. Res., v. 17, p. 179-191. 2002.
NAVI, P.; GIRARDET, F. Effects of thermo-hydro-mechanical treatment on the structure and properties of wood. Holzforsch , v. 54, p. 287-293. 2003.
NORIMOTO, M. Heat treatment and steam treatment of wood. Wood Ind., v. 49, n. 12, p. 588-592. 1994.
NORIMOTO, M. Large compressive deformation in wood. Mokuzai Gakkaishi, v. 39, n. 8, p. 867-874. 1993.
PHUONG, L. X. et al. Effects of heat treatment on brittleness of Styrax tonkinensis wood. J. Wood Sci., v. 53, p. 81-186. 2007.
SEBORG, R. M. et al. Heat-stabilized compressed wood (Staypak). Mech. Eng., v. 67, p. 25-31. 1945.
STAMM, A. J.; HARIS, E. E. Chemical Processing of Wood., New York: Chemical Publishing Co. Inc., 1953. 165p.
STAMM, A.J. Wood and Cellulose Science. New York: Ronald Press, 1964. 549p.
SUNDQVIST, B. et al. Determination of formic-acid and acetic acid concentrations formed during hydrothermal treatment of birch wood and its relation to colour, strength and hardness. Wood Sci. Tech ., v. 40, p. 549-561. 2006.
TABARSA, T.; CHUI, Y. H. Effects of hot-pressing on properties of white spruce. For. Prod. J., v. 47, n. 5, p. 71-76. 1997.
TABRSA, T. The effects of transverse compression and press temperature on wood response during hot-pressing. 1995. 110p. Thesis (Master of Science in Forest Engineering) - The University of New Brunswick, Canada, 1995.
TARKOW, H.; SEBORG, R. M. Surface densification of wood. For. Prod. J.. v. 18, n. 9, p. 104-107. 1968.
UNSAL, O. et al. Decay and termite resistance, water absorption and swelling of thermally compressed wood panels. Int. Biodeterior. Biodegrad., v. 63, n. 5, p. 54-52. 2009.
UNSAL, O. et al. The effects of heat treatment on some properties and colour in eucalyptus (Eucalyptus Camaldulensis Dehn.) wood. Maderas Ciencia y Tecnologia, v. 52, n. 2, p. 145-152. 2003.
UNSAL, O.; CANDAN, Z. Effects of press pressure and temperature on the moisture content, vertical density profile and janka hardness of pine wood panels. In: INTERNATIONAL IUFRO DIVISION, 10., 2007, Maine. Proceedings ... Orono: Wood Drying Conference, 2007.
UNSAL, O.; CANDAN, Z. Moisture content, vertical density profile and janka hardness of thermally compressed pine wood panels as a function of press pressure and temperature. Drying Tech., v. 26, n. 9, p. 1165-69. 2008.
WANG, J. M. et al. Effect of oxidation on heat fixation of compressed wood of China fir. For. Stud. in China, v. 2, n. 1, p.73-79. 2000.
WANG, J.; COOPER, P. A. Effect of grain orientation and surface wetting on vertical density profiles of thermally compressed fir and spruce. Holz als Roh-und Werkst., v. 63, p. 397-402. 2005b.
WANG, J.; COOPER, P. A. Vertical density profiles in thermally compressed balsam fir wood. For. Prod. J ., v. 55, n. 5, p. 65-68. 2005a.
WELZBACHER, C.R. et al. Thermo-mechanical densification combined with thermal modification of Norway Spruce (Picea abies Karst) in industrial scale-dimensional stability and durability aspects. Holz als Rohund Werkst., v. 66, p. 39-49. 2008.
YOSHIHARA, H.; TSUNEMATSU, S. Bending and shear properties of compressed Sitka spruce. Wood Sci. Tech ., n. 41, p.117-131. 2007.

Publication Dates

Publication in this collection
Apr-Jun 2013

This is an open-access article distributed under the terms of the Creative Commons Attribution License

[1] ATIK, C. Effect of sample position on colour values of wood under diffuse illumination. Rev. of the Faculty of Forestry, Istanbul, v. 56, n. 1, p. 73-79. 2006.

[2] AYADI, N. et al. Colour stability of heat-treated wood during artificial weathering. Holz als Rohund Werkst, v. 61, p. 221-226. 2003.

[3] AYDIN, I.; COLAKOGLU, G. Effects of surface inactivation, high temperature drying and preservative treatment on surface roughness and colour of alder and beech wood. Appl. Surf. Sci., v. 252, p. 430-440. 2005.

[4] BEKHTA, P.; NIEMZ, P. Effect of high temperature on the change in colour, dimensional stability and mechanical properties of spruce wood. Holzforsch, v. 57, p. 539-546. 2003.

[5] BLOMBERG, J. et al. Effects of semi-isostatic densification of wood on the variation in strength properties with density. Wood Sci. Tech., v. 39, p. 339-350. 2005.

[6] BOURGOIS, P.J. et al. The colour measurement: a fast method to study and to optimize the chemical transformations undergone in the thermically treated wood. Holzforsch , v. 45, p. 377-382. 1991.

[7] ESTEVES, B. et al. Heat-induced colour changes of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) wood. Wood Sci. Tech., v. 42, p. 369-384. 2008.

[8] KUBOJIMA, Y. et al. Effect of shear deflection on bending properties of compressed wood. Wood Fiber Sci., v. 36, p. 210-215. 2003.

[9] MONNONEN, K. et al. CIEL*a*b* Measurements to Determine the Role of Felling Season, Log Storage and Kiln Drying on Colouration of Silver Birch Wood. Scandinavian. J. For. Res., v. 17, p. 179-191. 2002.

[10] NAVI, P.; GIRARDET, F. Effects of thermo-hydro-mechanical treatment on the structure and properties of wood. Holzforsch , v. 54, p. 287-293. 2003.

[11] NORIMOTO, M. Heat treatment and steam treatment of wood. Wood Ind., v. 49, n. 12, p. 588-592. 1994.

[12] NORIMOTO, M. Large compressive deformation in wood. Mokuzai Gakkaishi, v. 39, n. 8, p. 867-874. 1993.

[13] PHUONG, L. X. et al. Effects of heat treatment on brittleness of Styrax tonkinensis wood. J. Wood Sci., v. 53, p. 81-186. 2007.

[14] SEBORG, R. M. et al. Heat-stabilized compressed wood (Staypak). Mech. Eng., v. 67, p. 25-31. 1945.

[15] STAMM, A. J.; HARIS, E. E. Chemical Processing of Wood., New York: Chemical Publishing Co. Inc., 1953. 165p.

[16] STAMM, A.J. Wood and Cellulose Science. New York: Ronald Press, 1964. 549p.

[17] SUNDQVIST, B. et al. Determination of formic-acid and acetic acid concentrations formed during hydrothermal treatment of birch wood and its relation to colour, strength and hardness. Wood Sci. Tech ., v. 40, p. 549-561. 2006.

[18] TABARSA, T.; CHUI, Y. H. Effects of hot-pressing on properties of white spruce. For. Prod. J., v. 47, n. 5, p. 71-76. 1997.

[19] TABRSA, T. The effects of transverse compression and press temperature on wood response during hot-pressing. 1995. 110p. Thesis (Master of Science in Forest Engineering) - The University of New Brunswick, Canada, 1995.

[20] TARKOW, H.; SEBORG, R. M. Surface densification of wood. For. Prod. J.. v. 18, n. 9, p. 104-107. 1968.

[21] UNSAL, O. et al. Decay and termite resistance, water absorption and swelling of thermally compressed wood panels. Int. Biodeterior. Biodegrad., v. 63, n. 5, p. 54-52. 2009.

[22] UNSAL, O. et al. The effects of heat treatment on some properties and colour in eucalyptus (Eucalyptus Camaldulensis Dehn.) wood. Maderas Ciencia y Tecnologia, v. 52, n. 2, p. 145-152. 2003.

[23] UNSAL, O.; CANDAN, Z. Effects of press pressure and temperature on the moisture content, vertical density profile and janka hardness of pine wood panels. In: INTERNATIONAL IUFRO DIVISION, 10., 2007, Maine. Proceedings ... Orono: Wood Drying Conference, 2007.

[24] UNSAL, O.; CANDAN, Z. Moisture content, vertical density profile and janka hardness of thermally compressed pine wood panels as a function of press pressure and temperature. Drying Tech., v. 26, n. 9, p. 1165-69. 2008.

[25] WANG, J. M. et al. Effect of oxidation on heat fixation of compressed wood of China fir. For. Stud. in China, v. 2, n. 1, p.73-79. 2000.

[26] WANG, J.; COOPER, P. A. Effect of grain orientation and surface wetting on vertical density profiles of thermally compressed fir and spruce. Holz als Roh-und Werkst., v. 63, p. 397-402. 2005b.

[27] WANG, J.; COOPER, P. A. Vertical density profiles in thermally compressed balsam fir wood. For. Prod. J ., v. 55, n. 5, p. 65-68. 2005a.

[28] WELZBACHER, C.R. et al. Thermo-mechanical densification combined with thermal modification of Norway Spruce (Picea abies Karst) in industrial scale-dimensional stability and durability aspects. Holz als Rohund Werkst., v. 66, p. 39-49. 2008.

[29] YOSHIHARA, H.; TSUNEMATSU, S. Bending and shear properties of compressed Sitka spruce. Wood Sci. Tech ., n. 41, p.117-131. 2007.

Brasil