Developing and Evaluating Composites Based on Plantation Eucalyptus Rotary cut Veneer and High density Polyethylene Film as Novel Building Materials
To achieve value added utilizations of plantation timbers, eucalyptus veneer/high density polyethylene film composites were prepared, with process factors (PF) (hot pressing temperature, HT; hot pressing duration, HD; hot pressing pressure, HP; HDPE film content, HC) and composite properties (CP) (water resistant bonding strength, BS; modulus of rupture, MOR; modulus of elasticity, MOE) investigated. According to thermal analyses, 140 to 180 degC was appropriate for HT. Based on statistical analyses, HD was easier to affect CP, while MOE was easier to be affected by PF. Quantitative relationships between PF and CP were determined by the neural network (ANN) modeling. In ANN simulation surveys, CP displayed Gaussian distributions (R2 0.9) when PF changed in current ranges, with positive correlations between BS and MOR (R2 0.5) Combining ANN and the genetic algorithm, optimal processes (HT, 160 degC; HD, 50 s/mm; HP, 1.3 MPa; HC, 6 layers) were found, and optimal results (BS, 1.30 MPa; MOR, 86.94 MPa; MOE, 8.33 GPa) were comparable to various reported poplar plywoods. Microscopic images demonstrated that composite interfaces were formed by the mechanical interlocking. The optimal BS attained Chinese standards for water resistant plywoods, so proposed composites can serve as water resistant and formaldehyde free building materials for furniture and interior design.