Influence of steaming on surface roughness of beech and sapele flooring material

The objective of this work is to evaluate effect of steaming on the surface roughness of beech (Fagus orientalis) and Sapele (Entandrophragma cylindricum) lumber. Surface characteristics of sawn and steamed of both species were determined employing a stylus type profilometer. Average roughness (Ra), mean peak-to-valley height (Rz), core roughness depth (Rk), reduced peak height (Rpk), and reduced valley depth (Rvk) roughness parameters were used to determine surface characteristics of the samples. Based on the results of statistical analyses measurements taken from the surface in both tangential and radial directions of two species did not result in significant difference at a 95% confidence level. However surface characteristics of beech and sapele samples after they were steamed at a temperature of 108 °C for 10 min showed statistically different from each other. It appears that steaming increased roughness of both species in tangential and radial directions. Based on the findings in this study, sapele specimen resulted in higher roughness values than those of beech at initial and final conditions. This study suggests that stylus method can be successfully used to evaluate and distinguish variations on the surface of wood due to steaming process as function of grain orientation. Data generated in this experimental study can be used as a quality control tool for further processes such as finishing or gluing of wood from two species.