EFFECT OF THE SAW BLADE CONSTRUCTION ON THE SURFACE QUALITY WHEN TRANSVERSE SAWING SPRUCE LUMBER ON CROSSCUT MITER SAW

The article deals with problematic of spruce wood cross-cutting. It focuses on the impact of the saw blades teeth number and use of chip limiting device saw blade on the surface quality during cross-cutting. Article is based on an experiment in which was used four saw blades with SK plates with uniform diameter (D = 250 mm) and uniform angular geometry (alpha = 15 degrees, beta = 60 degrees, gamma = 15 degrees). Three saw blades were characterized by different numbers of teeth (z = 24, 40 a 60) and one saw blade was chip limiting device saw blade. For the experiment were used tangentially sawn spruce samples with absolute humidity w(a) = 12 +/- 1%, and 50 mm of thickness. Cutting the spruce test samples was conducted to crosscut miter saw BOSCH GCM 10 S PROFESIONAL with the movement of the saw blade on a circular arc at a constant cutting speed (v(c) = 62 m.s(-1)) and at a sliding force (F-p = 15 N). The experiment showed that the surface quality - the arithmetic mean deviation of the roughness profile depending on the used saw blade varies from 4 to 18 mu m. The experiment demonstrated that the increase in the number of teeth of the saw blade increases the surface quality and that the use of chip limiting device greatly improves the quality of the surface.