Abstract

The article deals with the effect of thermal modification on the quality of the created surface during milling on CNC milling cutters. The quality of the created surface is evaluated based on surface roughness, specifically its roughness parameter Ra. The observed surface is created by a shank cutter with a diameter of 20 mm and three cutting edges in a spiral at a standard speed of 18,000. min-1. The article compares thermally modified pine wood and beech wood of at temperatures of 160, 180, 200 and 220°C with a reference sample of kiln dried wood of the given wood species. The article also monitors the variability of the quality of the created surface due to the change in the feed speed of 2, 4 and 6 m·min-1 and the thickness of removal of 1, 3 and 5 mm within the given degree of thermal modification. The article points to the fact that the average value of the arithmetic mean height (Ra) is below 10 μm for both types of wood, regardless of the degree of thermal modification. This meets the general requirements for the surface quality of furniture blanks. The mutual comparison of wood species showed that beech wood forms an average of 1.5 μm higher quality surface than wood pine. Thermal modification within both studied wood species improves the quality indicators of the created surface. In terms of the effect of specific temperatures, the highest quality of the created surface is at 180°C and deteriorates in the range of 180, 200, 160, 220°C. From the point of view of the influence of the investigated technological factors, no statistically significant influence of either the feed speed or the thickness of removed layer was demonstrated.

Authors (3)