Feasibility of wood peeling assisted by infrared heating

"Peeling" is the process of converting a log into a continuous thin (from 0.6 to more than 3 mm) ribbon of green wood termed "veneer" whose production plays an important role in the manufacture of light-weight packaging, plywood and Laminated Veneer Lumber (LVL) which are amongst the most widely used wood products. Prior to peeling, the round green-wood of most species needs to be heated to temperatures ranging from 30 to 90 degrees Celcius in order to soften the wood and ease cutting. Forming part of a broader program to develop a system that could be embedded on a peeling lathe, the foal of this PhD thesis was to investigate the technological feasibility of using infrared (IR) to heat green logs and so circumvent many of the economic and environmental disadvantages arising from soaking. The main output of this study was to demonstrate that the penetration depth of IR into green woods is limited to several tens of micrometers and that heat transfers into green wood up to the cutting plane (locating several millimeters underneath the surface) is by conduction, which is slow due to the insulating properties of wood. Heating green wood with IR radiation is therefore unsuitable for the high peeling rates currently in use in the industry.