Densification of Paullownia wood by using of hot-press

Abstract

For this study 10 logs of Paullowina.furtunie from Shastkalateh forest of Gorgan in Iran were selected randomly. After that, 45 clear flat swan specimens prepared and dried to 5% moisture. Density of each log and thickness of specimens were measured. Three levels of compression percent (16%, 33% and 50%) and temperature (130°C, 145°C and 160°C) were the variables. The physical properties of specimens such as spring back, compression set and thickness swelling were calculated. Also, MOE, MOR and impact resistance of specimens were evaluated. In order to have accurate examination, microscopic images were taken. Results show that, with increasing in compression percent, the amounts of spring back and thickness swelling enhance. Densification with 16% compression, yields deformation in elastic region while 33% and 50% compression, causes more compression set. The more compression percent, the more mechanical strengths and the highest strength attained in 50% compression. The effect of temperature was insignificant mostly. Finally, the proper treatment for Paullownia densification, was 130°C and 50% compression. Microscopic images asserted the above results and illustrated that, the enhancing of densification above 50% compression is possible.

Keywords

• Densification
• Paullownia
• Thermal treatment
• Mechanical strength
• Spring back
• Compression set