Застосування термомодифікованого шпону для захисту дерев’яних виробів від зволоження

The analysis of the process of thermal modification of wood was carried out and it was found that the treatment causes chemical changes in the structures of wood components (lignin, cellulose and hemicellulose). It has been proven that the thermal modification process causes the decomposition of hemicelluloses and the amorphous part of cellulose, reduces water absorption, and reduces the amount of substances that are a breeding ground for fungi, which leads to increased durability. In addition, lignin and the resulting pseudolignin undergo polymerization and redistribution throughout the cell volume, giving the cell walls greater density, hardness, and increased hydrophobicity (water repellency), thereby reducing their ability to absorb moisture and swell. It was determined that the oak veneer samples gained the most moisture from the environment in the first two days. The weight of unmodified veneer increased by 0.06 g, and similar results were shown by veneer modified at lower temperatures. The thermally modified veneer at 250 °C for 20, 30 minutes and at 280 °C gained 2 times less weight in the first two days - 0.03 g. Over the next 11 days, the control samples gained another 0.09 g, slightly less for samples modified at 160 °C, and modified at 220 °C and above ‒ no more than 0.03 g. Experimentally, it was found that compared to unmodified veneer, which gained 22.41 % moisture in two weeks, veneer modified at 250 and 280 °C gained 2.5 times less moisture – an average of 8.6 %. It was found that as the modification temperature increases to 280 °C, water absorption decreases more than twice. The results of the research will also allow us to target further tasks to create new methods of thermal modification of wood and its operating conditions at various facilities. The results of the research will also allow us to target further tasks to create new methods of thermal modification of wood and its operating conditions at various facilities.