Utjecaj termičke modifikacije hrastovine na granulometrijski sastav piljevine

Abstract

This paper presents the results of granulometric analyses of sawdust of thermally modified oak wood and unmodified oak wood sawed on narrow-kerf sash gang saw. Sawdust of dry thermally modified 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 unmodified oak wood sawdust consists of chips in the granularity range from 0.0448 mm to 12.1 mm. In both cases polydispersive fibrils with a strong extension in one dimension were observed. It can be concluded that thermally modified oak sawdust is finer, 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.U radu su izneseni rezultati granulometrijske analize piljevine termički modificirane i nemodificirane hrastovine. Uzorci piljevine dobiveni su piljenjem modificiranoga i nemodificiranog drva pilom jarmačom male širine propiljka. Piljevina suhe termički modificirane hrastovine, dobivena u procesu piljenja jarmačom PRW 15–M posmičnom brzinom 0,36 i 1,67 m·min-1 sadržava drvne čestice veličine 0,0412 – 3,6 mm a piljevina nemodificirane hrastovine sadržava čestice veličine 0,0448 – 12,1 mm. Može se zaključiti da se piljevina termički modificiranog drva sastoji od sitnijih čestica, sa znatno većim udjelom frakcije čestica veličine a = 125–500 μm i nešto većim udjelom frakcije čestica veličine a = 32–125 μm