Influences of back microbevel on orthogonal wood cutting

In the wood peeling process and more generally in the orthogonal cutting of green woods, we often use tools having a small bevel angle, usually 20°. This sharpness makes the edge very sensitive to wood defects and brings about difficulties to maintain its integrity. We propose to study the influence of a microbevel on the clearance face of a knife in the peeling of British Columbia pine specifically on the wear of edge and on the cutting forces. On the standard knives for peeling with a bevel angle (β 1 ) of 20° (see figure 1), we add microbevels with angle (β 2 ) varying from 22° to 35°. We study the influence of the microbevel length (L) (0 to 0.4 mm) and the microbevel angles on the cutting forces (Xc and Yc). To understand the influence of the microbevel on the tool wear rate, we measure the geometry of the edge at 0, 0.5, 1, 2 and 3 km of peeling. At the same time, we also take samples of the veneer produced at the beginning, the middle and the end of a log-peeling test to estimate the effect of the microbevel on the veneer quality. In addition, a simulation by finite elements on the contact between the tool and wood during the cutting provides information on the distribution of the stresses at the tool tip and in the wood in the cutting zone.