Iranian Journal of Wood and Paper Science Research
Year:2002 | Volume:- | Issue:15|Papers Count:5

Threes, six and 12 years old sample trees of Populos deltoides 77.51 were randomly selected and felled at the safrabasteh research station located in Gilan province. Sample tree transferred to the Alborz research center- Karaj for Laboratory studies; The Laboratory studies included determination of physical, anatomical and chemical composition of revealed that with increasing trees age, fiber length and fiber diameter increased. There was significant differences among three ages studied at I percent probability.

In this research, worked on two juniper trees (Juniperus exelsa L.) in Bakhtiari region as a part of Irano-touranian district. We noted the Sp. Gr. Of wood based on saturated volume 0.52, porosity 64%, volume shrinkage and swelling 10% and 11.3% resp. Anatomical structure and microscopic characteristics had been investigated incidentally. The average length of tracheids 1.3 mm. And the diameter, lumen diameter and thickness of cell wall of tracheids were determined 23.4, 16.3 and 3.5 microns resp. the major pulp indexes are calculated via related formulas.

In this study physical and mechanical properties of Hornbeam (Carpinus betulus L.) grown at three different elevations of Asalem Forests located at the north west of Gilan were investigated following the ASTM Standard. Sample trees were selected from 3 different elevations, at different height of trees, at 4 different geographical directions of the stems and 2 different moisture contents.The results of statistical analysis revealed that properties of Hornbeam wood from this region was influenced by elevations and to the lessees extend to geographical direction of wood specimens and tree height.

In this experiment the optimum condition of particleboard uom Date palm residues and prosopis (Mesquite) produced in southern part of Iran was investigated. Variable factors as type of raw-material (Date palm and prosopis), resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) and total of 18 combinations of variables were investigated.Other factors such as type of resin (UF), hardner content (2 percent) type of hardner (NH4CI)press closing time (4.5 mm/sec.), board density (0.7gr/cm3) press pressure (30 kg/cm2) and press temperature (160 C) were held constant.All boards were tested according to DIN-68763 standard. The factorial experimental design at completely random blocks test was used. The results of this study could be summarized as follows: Increasing the resin content from 9 to 11 percent increased MOR, MOE and ID and decreased thickness swelling after two and 24 hours immersion in water.The highest internal bond (IB) was related to prosopis (Mesquite) boards made at 5 minute, prass time. As far as production of date plam and prosopis (Mesquite) wood is concerned, the results revealed that the polymerization of resin and wood is better at 11 percent resin content and 5 minutes of press time. Date palm residues are important with treatment process according to reference. NO. One. Shape and dimension of chipped and flaked particles of date palm residues are important, because type and characteristics of species are different, in the mean time, as date palm residues has very high bulk density and specific surfaces than prosopis (Mesquite) which it has inverse effect on both physical and mechanical properties, thus it should be considered during the process of particleboards production.