Thermal modification of eucalyptus grandis wood: Variation of colorimetric parameters

Abstract

The color modifications in Eucalyptus grandis thermally modified wood were investigated. One hundred eighty specimens (10 x 10 x 200 mm) were prepared and thermally modified in an electric kiln for 4 and 8 h at 180-240°C. The color parameters (L*, a*, b*, C*, h* and ?E) were determined by the CIE-L*a*b* method on radial and tangential sections of untreated and treated wood. The results indicated the darkening of specimens in the radial and tangential sections. Both sections showed variation of L* between 73 and 30, a* between 9 and 5 and b* between 20 and 8. The thermally modified wood at 180 and 200°C showed similar patterns, equally at 220 and 240°C. The time of exposure indicated significance just in treatment at 200°C.