Process Optimization for Multi-Veneer Hot-Press Drying

The 1 to 20 veneers of Eucalyptus saligna were dried using a hot press with a pressure of 0.1–0.4 MPa and a temperature of 120–160°C.The energy consumption and properties of the veneers were examined. Although the contact angle (CA) was increased, the value of modulus of elasticity (MOE) was increased and energy consumption (Q) was reduced as the pressure increased. Three regression equations (pressure, temperature, veneer numbers as functions of Q, CA, MOE) were developed and a nonlinear programming model was derived with operation research theory to obtain the minimum Q or most desirable properties process under some production constraints. In cases where minimum Q is desired, the maximum CA of 180° and MOE of 18 GPa are required. The optimal solution was the minimum Q of 176.48 KJ, which can be obtained with a pressure of 0.4 MPa, temperature of 160°C, and veneer number of 5, which makes CA and MOE for the hot-press-dried veneer equal to 133.30° and 4.53 GPa, respectively.