Heat-Conduction Problems in Presses Used for Gluing of Wood

Abstract

The application of heat-flow equations to the heat-flow problems in wood-gluing presses is considered. By means of a transmission-line analogy, the solution of heat-flow problems with internally generated heat is greatly simplified. The general equation is set up and applied specifically to the problem of radio-frequency heating of wood, while the wood is contained between two cool plates. Comparison of this type of heating with the usual hot-plate-press method reveals important advantages for the radio-frequency method. The formulas developed have been illustrated by means of curves based upon the constants of wood. However, the general equations apply as well to the heating of any other insulating material, where the heating by radio frequency is done by essentially a dielectric-loss phenomena.