RESPONSE OF COLOUR AND HYGROSCOPIC PROPERTIES OF SCOTS PINE WOOD TO ΤHERMAL ΜODIFICATION

Year 2012, Volume: 14 Issue: 22, 96 - 103, 01.06.2012

Vasiliki Kamperıdou İoannis Barboutıs Vasileios Vasıleıou

Abstract

The effect of heat treatment on wood surface colour and hygroscopic properties of pine wood were
investigated in this study. Boards of Scots pine wood (Pinus sylvestris L.) were subjected to thermal
treatment at 200 °C, for 4, 6 and 8 hours. The change of equilibrium moisture content and density
values of the specimens, due to the thermal treatment were recorded, in order to facilitate the
understanding of the treated material behavior. The colour parameters L*, a* and b*, used to depict
the total colour change (ΔΕ) of wood surface, were proved to change proportionally to the treatment
intensity. Moreover, the swelling in tangential and radial direction and the absorption of the specimens
as well, appeared to be enhanced in great extent by the thermal treatment process. Mean value of
Swelling percentage in tangential direction decreased 10.26%, 17.22% and 19.60% for specimens
treated for 4, 6 and 8 hours, respectively, referring to the final measurement after 72 hours of
immersion. In radial direction, mean value of Swelling percentage decreased 19.56%, 32.75% and
34.65% for treated for 4, 6 and 8 hours specimens, respectively, after 72 hours immersion, which
attests the swelling decrease and the improvement of the hygroscopic behavior of Scots pine wood.

Keywords

Thermal treatment

RESPONSE OF COLOUR AND HYGROSCOPIC PROPERTIES OF SCOTS PINE WOOD TO THERMAL MODIFICATION

Abstract

The effect of heat treatment on wood surface colour and hygroscopic properties of pine wood were
investigated in this study. Boards of Scots pine wood (Pinus sylvestris L.) were subjected to thermal
treatment at 200 °C, for 4, 6 and 8 hours. The change of equilibrium moisture content and density
values of the specimens, due to the thermal treatment were recorded, in order to facilitate the
understanding of the treated material behavior. The colour parameters L*, a* and b*, used to depict
the total colour change (ΔΕ) of wood surface, were proved to change proportionally to the treatment
intensity. Moreover, the swelling in tangential and radial direction and the absorption of the specimens
as well, appeared to be enhanced in great extent by the thermal treatment process. Mean value of
Swelling percentage in tangential direction decreased 10.26%, 17.22% and 19.60% for specimens
treated for 4, 6 and 8 hours, respectively, referring to the final measurement after 72 hours of
immersion. In radial direction, mean value of Swelling percentage decreased 19.56%, 32.75% and
34.65% for treated for 4, 6 and 8 hours specimens, respectively, after 72 hours immersion, which
attests the swelling decrease and the improvement of the hygroscopic behavior of Scots pine wood.

Keywords

Colour, Hygroscopic properties, Modification, Scots pine, Thermal treatment

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