EFFECT OF MICROWAVE RADIATION AND PRE-STEAMING TREATMENTS ON THE CONVENTIONAL DRYING CHARACTERISTICS OF FIR WOOD (ABIES ALBA L.)
hadi dashti, asghar termian, mehdi Faezipour, mehdi Shahverdi
In this research, the effect of microwave radiation and steaming pretreatments on drying rate and residual stresses of fir wood (Abies alba L.) was investigated. Wood samples with green dimensions of 340 × 100 × 50 mm and initial moisture content of about 50% were exposed to either steam or microwave radiation treatment before being conventionally dried. The pre-steaming was performed at temperatures of 120, 140, and 160°C for 1 hour, and the microwave treatment was applied with 2.45GHz frequency for 7 and 10 minutes at three different conditions. Results revealed that the pre-steaming at 140 and 160°C and the microwave radiation for 10 minutes imposed greater effect on the drying rate. The residual drying stresses were reduced due to the microwave radiation; in contrast, they were increased as a result of steaming at 140 and 160°C.
Drying rate; Residual stress; Steaming; Microwave; Fir wood