Influencing Factors on Looseness of Chipped Material Generated during Wood Planing

Autor: Matija Jug, Ružica Beljo Lučić, Anka Ozana Čavlović
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Drvna Industrija, Vol 67, Iss 3, Pp 229-239 (2016)
Drvna industrija
Volume 67
Issue 3
ISSN: 1847-1153
0012-6772
Popis: Poznavanje faktora rastresitosti i nasipne gustoće usitnjenog materijala nastaloga u procesu mehaničke obrade drva važno je radi optimalnog izbora sredstava za rukovanje, transportiranje i skladištenje, ali i radi trajnosti i kvalitete usitnjenog drva kao sirovine za izradu drvnih proizvoda od usitnjenog drva. Faktor rastresitosti usitnjenoga drvnog materijala defi niran je kao omjer volumena usitnjenog materijala i cjelovitog drva od kojega je nastao. U radu je analiziran utjecaj posmične brzine, prednjeg kuta rezne oštrice i vrste drva na faktor rastresitosti usitnjene blanjevine. Odabrani su uzorci jelovine, hrastovine, parene bukovine i termički modificirane bukovine (pri temperaturi od 212 °C) dobiveni blanjanjem pri četiri posmične brzine (vp1 = 6; vp2 = 12; vp3 = 18 i vp4 = 24 m/min) i tri prednja kuta oštrice (γ1 = 15°; γ2 = 20° i γ3 = 25°). Povećanje posmične brzine utjecalo je na smanjenje faktora rastresitosti samo za uzorke bukovine i jelovine. Utjecaj prednjeg kuta oštrice pri blanjanju različitih vrsta drva nije jednoznačan. Debljina strugotine nije se pokazala najvažnijim činiteljem koji utječe na faktor rastresitosti nego je to smjer rezanja u odnosu prema smjeru vlakanaca drva te oblik nastale čestice i njezina lomljivost. Najveći faktor rastresitosti dobiven je za blanjevinu jelovine pri najmanjoj posmičnoj brzini (fr = 28,42), a najmanji faktor rastresitosti zamijećen je za blanjevinu termički modificirane bukovine (fr = 2,62). Dobiveni rezultati za faktor rastresitosti blanjevine višestruko su veći od navoda u literaturi.
It is necessary to know the looseness factor and bulk density of chipped wood generated in the mechanical wood processing to make the optimal choice of equipment for handling, transportation and storage, and also to determine the durability and quality of chipped wood as raw material. The looseness factor of chipped wood is defined as the ratio of volume of chipped wood and volume of solid wood. This paper presents the analysis of the effect of feed speed, rake angle and wood species on the looseness factor of chips generated in planing solid wood. Selected samples of chipped pine-wood, oak-wood, steamed and thermally modified beech-wood (at temperature of 212 °C) were generated in planing at four different feed speeds (vp1= 6; vp2=12; vp3=18 i vp4=24 m/min) and three rake angles (γ1 = 15°; γ2 = 20° i γ3 = 25°). The increase of feed speed only affects the reduction of the looseness factor for beech-wood and fir-wood. The impact of the rake angle during planing of researched wood species is not entirely clear. The presumed significant influence of cutting depth on the looseness factor was not established but significant influence was found of the cutting direction relative to the wood grain direction, the particles shape and their ability to fragmentation. The maximum looseness factor was obtained for chipped litewood generated during planing of fir-wood at minimum feed speed (fr=28.42) and the lowest in planing thermally modified beech-wood (fr=2.62). All obtained looseness factors were several times higher than those quoted in the literature.
Databáze: OpenAIRE
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