Investigation of the Effects of Heat Treatment Applied to Beech Plywood

The aim of this study is to determine the effects of heat treatment on some physical and mechanical properties of beech plywood boards. The 3-layered beech plywood boards with a thickness of 3.9 mm were subjected to heat treatment for 1, 2 and 3 hours at temperatures of 160, 180 and 200 °C. These beech plywood boards were tested for physical properties such as density, water absorption and thickness swelling, mechanical property tests such as modulus of rupture (MOR) and Brinell hardness, and mass loss rates according to the relevant standards. The results obtained show that the hydrophobicity of beech plywood boards is improved but the strength and weight loss are adversely affected, depending on the temperature and duration of heat treatment. It has been found that beech plywood boards heat-treated at 200 °C for 3 hours can be used in very humid environments for average mechanical stresses of wood parts with a reduced thickness swell of 4 % and a reduced water absorption rate of more than 12 %.