The Influence of Heating on Wood Hygroscopicity and Dimensional Stability

Abstract

The influence of thermotreatment on moisture exchange between wood and natural environment with variable air parameters as well as on dimensional stability of wood was studied. Experiments were carried out with pine wood samples in heated premises and outside. Prior to study the samples were heated at 60, 80, 100 and 120 °C temperature at the heating duration of 24, 48, 72 and 96 hours. It was found that moisture content of wood and its fluctuation as well as dimensional stability after thermotreatment completely depend on the heating temperature and duration. The higher the temperature and the longer the heating duration, the less hygroscopicity of wood is found, while the dimensional stability becomes higher. The effect of thermotreatment is especially observed on exploitable wood moisture content and its variations in premises. Actual moisture content in premises decreases even on 40 % as compared to the moisture content of untreated samples, while outside it decreases by 20 %. The change of moisture content in premises decreases almost twice, while outside on 1.7 times.