عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Background and scope
Biometrical, physical and chemical properties of various wood species are important factors for determination, identification and their applications. Persian oak (Quercus brantii Lindl.) from Fagacea family is the most abundant and important tree species in west and southwest provinces of Iran that its biometrical, physical and chemical features is not studied so far. In this study, the mentioned properties of Persian oak from Lordegan township of Charmahal va Bakhtiari province were measured. The properties are included the biometrical (fiber length, fiber diameter, lumen and cell wall thickness), physical (density and volumetric shrinkage and swelling) and chemical properties (cellulose, hemicellulose, lignin and ash content). By measuring and investigating of these characterizes could be obtained valuable information in terms of cell elements and their relationships with natural durability.
Material and Methods
This study was carried out in the forest of Atashgahe village in 55 kilometers from southwest of Lordegan Township. Lordegan Township is one the most important forest stands in Charmahal va Backtiari.
In this study, three normal trees with the diameter about 35cm were chosen to determine the biometrical (fiber length, fiber diameter, lumen and cell wall thickness), physical (density and volumetric shrinkage and swelling) and chemical features (cellulose, hemicelluloses, lignin and ash content). Form each tree; three disks were prepared at breast height of tree and testing samples were prepared along radial direction (pith, middle and bark) and then the mentioned properties were measured. Defiberation was done according to Franklin method. Determination of density was carried out based on ISO-3131standard. Cellulose, lignin and ash content were measured in accordance with TAPPI T-264-om-88 and T-222-6m-88 respectively. The content of ash was evaluated based on ASTM D1107-84.
The results indicated that fiber length, fiber diameter, lumen and cell wall thickness in radial direction were 967.67, 17.14, 3.67 and 6.41 micron, respectively. Results also showed that dry and basic density were 1.01±.10and 0.91 g/cm3, respectively. Volumetric shrinkage and swelling were 10.12 and 11.29 percent, respectively. The chemical results showed that content of cellulose, hemi cellulose, lignin and ash in sap- and heartwood were 37, 25, 1,19, 3,13, 41, 23, 2,6, 3,56 %, respectively.
In general, the results of the present study showed that the biometrical and physical properties increased along radial direction from the pith to the bark. On the other hand, Persian oak with fiber length 0.97 mm is considered as moderate fibers. Chemical analysis indicated that cellulose, extractive and ash content in the heartwood were higher than the sapwood. There was no statistical significant different at 5 percent level between the cellulose content values in heartwood and sapwood. According to the measured dry density (1.03 g/cm3), Persian oak is categorized as heavy wood species.