Temperature Distribution in White-Oak Laminated Timbers Heated in a High-Frequency Electric Field

High-frequency dielectric heating has been applied to the process of laminating commercial white-oak ship timbers. Specimens 6 × 6 × 24 in., composed of eight laminations ¾ × 6 × 24 in., were heated both with and without glue to study the temperatures obtaining in the glue-line areas. The uniformity of temperatures depends upon the density, moisture content, and arrangement of the laminations, direction of the electric field, and thermal insulation of the heated material. The effect of these variables is greater when the electric field and glue lines are parallel than when they are mutually perpendicular. Thermocouples were used for rapid temperature measurement. A method of heating the sides of timbers effectively was developed.