Effect of thermal modification of oak wood on sawdust granularity.

This paper presents the results of granulometric analyses of sawdust of thermally modifi ed oak wood and unmodifi ed oak wood sawed on narrow-kerf sash gang saw. Sawdust of dry thermally modifi ed oak, produced during the sawing process on the frame sawing machine PRW 15–M with the feed speed of 0.36 and 1.67 m·min-1, consists of chip granularity in the range from 0.0412 mm to 3.6 mm, whereas the unmodifi ed oak wood sawdust consists of chips in the granularity range from 0.0448 mm to 12.1 mm. In both cases polydispersive fi brils with a strong extension in one dimension were observed. It can be concluded that thermally modifi ed oak sawdust is fi ner, with a distinct larger participation of the fraction in the granularity range a = 125–500 μm and a slightly increased share of the fraction in the range a = 32–125 μm.