Effect of hemp oil impregnation and thermal modification on European beech wood properties

Thermal modification of wood is an environment-friendly method, which, among others, enhances wood water related properties, whereas the use of hot oil as a heating medium generally leads to better performance. In this study, European beech wood was hemp oil-impregnated, thermally modified at 200 °C and both ways of treatment were combined. Analysis of the treated wood included the determination of the change in important wood characteristics—colour, hygroscopicity, dimensional stability, bending properties, and decay resistance against white rot. The results indicate that heat treatment combined with oil has influenced the properties of beech wood more than heat treatment itself. In certain cases, the high effectiveness is only relative with regard to mass increase caused by high oil retention.