Optical measurements of sawdust dimensions

This article deals with optical measuring of sawdust dimensions by IP camera. Optical methods of sawdust dimensions measurement are relatively extended and offer more information about measurement sample than other methods. By descripted method it is possible to specify dimensions, perimeter, area of each particle, as well as eccentricity, centroid position, segmentation of edges and other. Using IP cameras to obtain the image with samples it is possible to measure sawdust, e. g. at the manufacturing, and to evaluate the results at another location (laboratory). This eliminates need to carry a measuring system to measuring location. Compared to other methods (e. g. sieve method), descripted method is repeatable because the samples are not mechanical damaged and crumbed by jolting through the sieves.

Cutting power during lengthwise milling of thermally modified oak wood

The paper presents experimental results of cutting power of thermally modified and non-modified hardwood of Summer oak (Quercus robur) during lengthwise milling. The process of heat treatment was performed in the atmosphere of superheated steam, at temperature 210ºC. Cutting power was determined during milling of the radial surface of modified and non-modified samples. It was calculated as the difference of power consumption by a milling machine during wood machining and at idling. Several cutting regimes were tested by combining different values of rotation speed, feed speed, rake angle and constant cutting depth ae = 1 mm. The values of cutting power are approximately the same at the kinematic angle of the tool head γ = 15°, 30°; there are bigger differences for γ = 20°. The decline of cutting power in the thermally modified (210°C) oak wood machining compared to natural oak wood is 21.7% ÷ 22.2% at the cutting speed vc =40 m. s-1.