- Willey, Ronnie M.
The Graduate School, University of Maine
In this research, the thermal conductivity of oriented strand board (OSB), composed of aspen flakes and phenol formaldehyde resin, was measured in directions normal, parallel, and perpendicular to surface flake orientation. Samples were prepared from three, four foot by eight foot sheets, and randomly divided into groups for steady state and transient thermal conductivity measurements. Both stay state and transient values of thermal conductivity were calculated parallel to the surface. Only steady state calculations of thermal conductivity were done through the thickness of the boards. Measurements were done at two moister content conditions.
Overall, thermal conductivity ranged from 0.088 W/mC to .594 W/mC. The highest values were found in the transverse direction of the boards. Upon analysis, porosity variations were found to have a greater effect on thermal conductivity in the radial directions. For the through the thickness calculations, moisture content was found to have a greater effect than density variations. Core samples, prepared by removing the denser surface layers, were also tested under the same conditions to determine if the surface layers affected thermal conductivity. It was determined that no significant effect was present due to surface layers.
The information on directional differences in thermal conductivity will help in modeling the heat transfer in the pressing process of OSB and will help in optimizing the pressing processes in the future.