DEPENDENCE OF ROUGHNESS CHANGE AND CRACK FORMATION ON PARAMETERS OF WOOD SURFACE EMBOSSING

摘要

This paper deals with roughness change and crack formation after surface embossing of aspen wood. Embossing was carried out with three various shapes of embossing wedges (convex, concave and with 45 angle). The embossing was realized with two temperatures, 20 and 160 degrees C. The surface roughness before and after embossing was evaluated on the basis of the arithmetical mean deviation of the roughness profile, R-a. Surface quality measurements were carried out in perpendicular (transversal) and parallel (longitudinal) direction in relation to wood fibers. Embossment area quality was evaluated by the mean of portion of cracks in embossment. This evaluation was based on digital image of embossed area and subsequently calculation of portion of cracks area in relation to total evaluated area. Elevated temperature has a positive effect on the quality of the surface, because of roughness decrease. However, the increase in temperature causes a growth in the proportion of cracks on the embossed surface.