The effect of tension wood on roughness of poplar wood and its modification by steaming

In this research, the effect of tension wood on the roughness of poplar wood in tangential and radial sections was investigated. Steaming at120 ̊C for 30 and 60 min was aslo applied to reduce the roughness. The potential use of roughness measurement technique for macroscopically detection of tension wood was one of the main objectives of this research. Before roughness measurement and for accurate sampling, the detection of tension wood was carried out using Herzberg reagent and microscopic studies. The roughness of samples was measured by stylus profilometer at 12 % moisture content and the surface quality was also studied by stereo-microscope. Results showed that there is no significant difference in the radial and tangential roughness between tension and normal wood. No difference was also observed between the roughness of tangential and radial sections of both types of woods. In contrast, stereo-microscopic studies clearly showed the higher roughness of tension wood. Steaming for 30 min increased the roughness but the treatment for 60 min had a decreasing effect on the roughness of both types of woods. Overall, it can be concluded that the roughness measurement technique cannot be used as a suitable method to nondestructively detect the poplar tension wood.