Cutting Power during Milling of Thermally Modified Pine Wood

The paper presents experimental testing results of cutting power of thermally modified wood of Scots pine (Pinus sylvestris L.) during lengthwise milling. The process of heat treatment was performed in the atmosphere of superheated steam, at temperatures of 130, 160, 190 and 220 degrees C, maintaining an identical heating time of 4 h for all modification variants. Cutting power was determined during milling of the radial surface of modified and non-modified samples. It was calculated as the difference of power used by a milling machine during wood machining and at idling. Based on the results of measurements, it was found that, in the case of modified wood, cutting power decreases with an increase in modification temperature (the dependence being linear) and increases with an increase in the working engagement. At temperatures exceeding 160 degrees C, the power required for milling of modified wood is lower than cutting power for non-modified wood. The experiment indicated a significant reduction of cutting power with an increase in wood modification temperature. It was also found that an increase in the working engagement results in an increase of cutting power both in thermally modified and non-modified wood.