Evaluation of heating temperature and time on bending properties of Taurus cedar wood

Abstract

Heat treatment is one of the environmentally friendly and cost-effective modification methods applied for improvements of wood properties. However, influences of exposure duration and temperature should be known to provide balanced improvements for properties. In this study, effect of temperature (80, 120, 150, 180, and 210°C) and exposure duration (2, 5, and 8 h) on the longitudinal ultrasonic wave velocity, density, dynamic Modulus of Elasticity-MOE (Edyn), MOE in bending, and Modulus of Rupture (MOR) properties of Taurus cedar (Cedrus libani) was figured out. Edyn was predicted using ultrasonic wave velocity of 2.25 MHz longitudinal ultrasonic wave propagated through the longitudinal axis. The three-point bending test was performed to determine static mechanical properties. According to results, the highest adverse effects of extended duration and temperature were observed for MOR and followed by Edyn, and MOE in bending. Up to 150°C and 8 h treatment levels, some remarkable increases (15.3%) were observed particularly for MOE in bending. Coefficients of determinations were calculated as 0.83, 0.38, and 0.37 for Edyn vs MOE in bending, Edyn vs MOR, and MOE in bending vs MOR, respectively.

Keywords

• cedar
• ultrasound
• modulus of elasticity
• modulus of rupture
• sedir
• ultrases
• elastikiyet modülü
• eğilme direnci