Evaluation of mechanical properties of laminated strand lumber and oriented strand lumber made from Poplar wood (Populus deltoides) and Paulownia (Paulownia fortunei) with urea formaldehyde adhesive containing nanoclay

Abstract

In this study, the mechanical properties of laminated strand lumber and oriented strand lumber were investigated. Two species of fast growing; Poplar (Populus deltoides) and Paulownia (Paulownia fortunei) were used. Urea formaldehyde resin was used to manufacture these products and this resin was reinforced with four levels of nanoclay (0, 2·5, 5 and 7·5%) based on dry weight of resin. Press temperature, press time and press pressure were 120°C, 5 min and 11 kg cm−2 respectively. Statistical analysis showed that the effects of species and nanoclay on the panel properties were statistically significant at 95% confidence interval. Modulus of rupture, modulus of elasticity, internal bond, shear strength and screw holding strength were analysed in boards. It was found that if nanoclay content was increased to 5 or 7·5%, all properties were significantly improved, when Populus deltoides was compared to Paulownia fortunei, the poplar panel had excellent performance.