Effect of heat treatment on the dimensional stability of ash (Fraxinus angustifolia Vahl.) wood

Abstract

In this study, the effect of heat treatment on dimensional stability of ash (Fraxinus angustifolia Vahl.) wood, which naturally grows in Turkey, was investigated. Ash wood samples were subjected to the heat treatment process at different temperatures (120°C, 160°C, 190°C, and 210°C) and for different time periods (3, 6 and 9 h) in water vapor atmosphere. Water absorption, water repellent effectiveness, anti-swell effectiveness (ASE, TS 4084) and Attenuated Total Reflection - Fouirer Transform Infrared Spektrofotometre (ATR-FTIR) were performed on the test samples. Generally, although water absorption decreased with an increase in treatment temperature and time period, the mean of water repellent effectiveness and ASE increased. It was determined that decreases in the absorbance value of the peak belong to the -OH stretching vibration depended on heat treatment temperature increases. In particular, ASE increased to >40% with a rapid increase after 3 hours application of heat treatment at 190°C. The highest dimensional stability (58.4%) of ash wood was detected in the highest heat treatment temperature and time period (210°C and 9 h, respectively). Therefore, it was shown that the value and product quality of solid products produced from ash wood with heat treatment can be improved without the use of toxic chemicals.