The colour difference of transparent surface finish on hydrothermally treated beech wood in the interior

The colour difference of transparent surface finish on hydrothermally treated beech wood in the interior. The paper deals with the influence of ageing of transparent surface finish in the dark and in the light in interior conditions. The colour difference of the tested samples with surface finishes (∆E*ab) was measured after the ageing of native wood and hydrothermally modified wood in the dark and in the light. In the experiment,European beech wood was hydrothermally treated at a temperature of 135 C under saturated water vapour for 6 hours. Three different types of surface finishes (acrylic-polyurethane, polyacrylic and aldehyde resin, alkyd resin) were applied on the wood surfaces. The colour parameters of the surfaces in the system CIE L*a*b*, chroma ΔC*,and hue angle Δh were measured immediately after surface finishing and after the ageing in the dark and in the light. The samples were placed behind windows glass in the interior for 60 days. The results of the colour difference ∆E*ab showed that the colour of wood and the colour of the surface finishes was changed after ageing in the dark as well as in the light. The colour difference ∆E*ab was bigger in the light than in the dark. The colour difference was bigger on native wood than on hydrothermally modified wood.