Effect of heat treatment (ThermoWood) on some surface properties of parquet beech (Fagus orientalis Lipsky.) with different layers of UV system applied

Abstract

Heat treatment is known to improve the stability and durability of various woods. However, in the process some surface properties are changed. This paper reports the changes in surface properties such as color, glossiness, pendulum hardness, and surface adhesion on coated heat-treated and untreated beech wood. The wood was coated with an epoxy acrylic resin sealer followed by a polyacrylic-based resin varnish that is normally applied on parquet with single and double layers according to the manufacturer's recommendations. The results showed that in relation to color parameters, the lightness decreased while a* increased in response to heat treatment. This was followed by a decrease in the redness (a*) and a decrease in yellow (b*) with the intensity of the treatment. There was an initial increase in the glossiness but it decreased later on with the severity of the treatment. The hardness and adhesion also decreased with the severity of the treatment for beech coated with single and double layers. The wood surface properties depended on the treating time and the temperature of the treatment.