Effect of thermal rectification on colors of Eucalyptus Saligna and Pinus caribaea Woods
Author
Sodero Martins Pincelli,Ana Lúcia Piedade
de Moura,Luiz Fernando
Brito,José Otávio
Abstract
Eucalyptus saligna and Pinus caribaea var. hondurensis woods underwent a variety of thermal rectification treatments (from 120ºC to 180ºC) to evaluate the effect of heating on their colorimetric properties. The following color parameters were measured: lightness (L), a* coordinate (green-red coordinate), b* coordinate (blue-yellow coordinate), saturation (C), and tonality angle (H). This study demonstrates that thermal rectification can be regarded as a tool for adding value to wood through color modification by heating. Results also suggest that thermal rectification might be a tool for homogenizing wood tonality and reddish color between species. Both tested species have shown very distinct colorimetric behaviors as a function of thermal treatments. The conifer was more resistant to thermal darkening than the hardwood while exposed to temperatures below 160ºC. The green-red coordinate (a*) and the tonality angle (H) tended to be homogenized for both species, as they decreased in eucalyptus, and increased in pinus, as a function of heating. The effect of wood heating on the blue-yellow coordinate (b*), saturation (C), and tonality angle (H) was likely to be opposite between both tested species.