Rational production of veneer by IR-heating of green wood during peeling: Modeling experiments

Abstract

Heating green wood logs by infrared (IR) radiation during peeling for veneer production has been numerically simulated, focusing on the heating kinetics of a green wood cylinder rotating with a decreasing radius. The results confi rm those of previous experiments, that this kind of heating is a promising alternative to soaking wood prior to peeling. The model integrates the green wood parameters such as moisture content, density, distribution and ratios of earlywood and latewood, on the one hand, and the peeling conditions of veneer thickness and peeling speed, on the other. The following heat transfer processes were considered: conduction within the bolt, external heating by the IR source, and convection between the bolt surface and the external environment. The outputs were the temperatures of the bolt surface and of layers several millimeters deep. For maximal heat penetration, the bolt should turn in front of the IR source before cutting starts and the IR source should be positioned at the greatest angular distance ahead of the knife. Several heating scenarios could be simulated by the model, thus it is a useful decision-making tool for the design of an in-line IR heating system installed on the peeling lathe.