Surface quality of thermally compressed Douglas fir veneer

The objective of this study is to evaluate surface quality of compressed Douglas fir (Pseudotsuga menziesii) veneer sheets in the form of its roughness. Veneer samples were compressed using pressure levels of 1.0 N/mm2, 2.0 N/mm2, and 2.5 N/mm2 at two temperatures of 180 °C and 210 °C for 3 min. A fine stylus profilometer was used to evaluate surface roughness of the veneer samples. Three roughness parameters, namely average roughness (Ra), mean peak-to-valley height (Rz), and maximum roughness (Rmax) values were determined. The results obtained in this study showed that the surface roughness parameters of the thermally compressed veneers decreased with increasing press temperature and pressure level. It appears that initial data found in this work would provide some benefit to more efficient use of adhesive to manufacture plywood and laminated veneer lumber (LVL) panels with enhanced properties.