Modification of the surface of thermally modified wood with ozone when creating glued structures

Abstract

The greatest interest of researchers is focused on the processes of heat treatment of wood, taking place in an airless environment at temperatures of 180-250 °C, since heat treatment of wood allows increasing its moisture resistance, reduce hygroscopicity, and increase resistance to decay. However, a decrease in the hygroscopicity of wood adversely affects the process of obtaining glued materials due to a decrease in the wettability of thermowood surface and, as a consequence, a decrease in adhesion characteristics. This work is devoted to the study of the effect of ozone on the surface of thermally modified wood to increase the adhesive properties during gluing. It has been determined that the ozonation contributes to an increase in the wettability of the surface layer of thermal wood by more than 15% due to the reactivity of ozone to oxidize and degrade ligno-containing products of wood. It was revealed that the modification of wood, including preliminary volumetric heat treatment followed by surface treatment with ozone, causes an increase in the strength of the glue line when operated in high humidity conditions. In connection with the results obtained, an improved technology for the production of glued load-bearing structures for wooden housing construction is proposed.