Analysis of Cutting Forces at Transverse Sawing of Wood with SK and HSS Saw Blades

This research deals with the processing of wood using a circular saw, which is associated with several risks and factors that affect the wood splitting process. One of them is the wear of the teeth of the saw blade and the change in the size of the cutting forces. The aim of this study is to compare real measured values and theoretical values when processing Norway Spruce wood, using two types of saw blades SK and HSS with a diameter of 600 mm and the number of teeth 54 and 56. Experimental measurements were carried out on a special test device with the possibility of moving the tested wood into the cutting devices and a simple saw blade replacement system. The results of the contributions show significant differences, based on defined factors, which are supported by FEM analysis of cutting forces in the process of cutting wood - when changing the design of the saw blade. The results of the experiment show that the cutting conditions (cutting speed, feed speed) do not have a significant effect on the size of the cutting forces. The theoretical and real stress values for HSS discs ranged from 14 to 22 MPa. Significantly larger differences were recorded for discs with SK, where the real values of the maximum stresses were around 14 MPa and the theoretical ones around 25 MPa. When cutting spruce with a disc with SK slices, the maximum values of the the-oretical cutting forces were in the range of 76 to 94 N and the maximum values of the measured cutting forces were in the range of 40 to 44 N.