Physics and Mechanical Wood
Mohamad ali Sadatnia; noshin sattari; mehran roohnia; mohsen bahmani
Abstract
The goal of this study was to determine the modulus of elasticity and modulus of rapture of two kinds of date palm (Khasi and Hajmohammadi) using static bending and dynamic (flexural vibration) techniques. To reduce the difference between static and dynamic stiffness values, the static bending modulus ...
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The goal of this study was to determine the modulus of elasticity and modulus of rapture of two kinds of date palm (Khasi and Hajmohammadi) using static bending and dynamic (flexural vibration) techniques. To reduce the difference between static and dynamic stiffness values, the static bending modulus of elasticity was modified by taking into account the value of the shear deflection. In addition to, for better understanding of the mechanical properties of date palm, values were compared with those measured for poplar samples. The results showed that, in Khasi the mean values of the modulus of elasticity obtained by flexural vibration, the static modulus of elasticity, the modified static modulus of elasticity and as well as the modulus of rapture were 47, 67,68 and 38% less than those measured for Hajmohammadi respectively. In comparing with date palm, values measured for poplar samples were more pronounced. The difference between dynamic and static values of modulus recorded for Khasi, Hajmohammadi and poplar samples were 63, 40 and 19% respectively. After modification of the static values, the difference was reduced in to 3% for Khasi, 6% for Hajmohammadi and 7 % for poplar experimental samples. Finally the significant correlation coefficients were found between the static and the dynamic modulus of elasticity for both two kinds of date palm.
Asghar Taremian; Zinab Frozan; Amir Sepehr; Hadi Ghlamian; Reza Oladi
Abstract
In this study, the physical and anatomical properties of old date palm wood (Phoenix dactylifera L.) and its drying behavior was studied. Four old date palm trees grown in Bam city (Kerman provenience) were felled. Then, boards with the dimension of 300 × 50 × 30 mm were cut at DBH of trees ...
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In this study, the physical and anatomical properties of old date palm wood (Phoenix dactylifera L.) and its drying behavior was studied. Four old date palm trees grown in Bam city (Kerman provenience) were felled. Then, boards with the dimension of 300 × 50 × 30 mm were cut at DBH of trees from pith to bark. After measuring the green moisture content and specific gravity, boards were dried in a semi-industrial kiln to reach the final moisture content of 8% using a mild wood drying schedule. Cross-sectional anatomical measurements were performed on the nearest boards to the bark and pith. Results showed that the green moisture content and specific gravity of date palm wood ranged between 150-260% and 0.29–0.39 and the moisture content was increased and the specific gravity was decreased from pith to bark. Anatomical observations and statistical analysis revealed that there was no statistically significant difference between average number of vessel elements and vessel bundles between pith and bark, but the mean vessel area in pith was considerably greater than bark. Results also showed that the drying rate of date palm wood was high reaching to the final moisture content of 8% within 7 days. Drying rate of bark samples was higher than those of the pith and no deformation and surface crack was observed in the dried boards.
Composite wood products
Amir Nourbakhsh; Abolfazl Kargarfard
Abstract
In this study the effect of resin content and press time of particleboard from Date palm residues, Eucalyptus camaldulensis, Tamarix residues and prosopis (Mesquite) producted were investigated in southern of Iran.Variable factors as resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) ...
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In this study the effect of resin content and press time of particleboard from Date palm residues, Eucalyptus camaldulensis, Tamarix residues and prosopis (Mesquite) producted were investigated in southern of Iran.Variable factors as resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) and total of 27 boards were fabricated. Other factors such as type of resin (UF), hardener content (2 percent) type of hardener (NH4Cl) press closing time (4.5 mm/sec.), board density (0.7 gr/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 test was used. The results of this study could be summarized as follows:Increasing the resin content from 9 to 11 percent, MOE and IE and decreased thickness swelling after two and 24 hours immersion in water. The results revealed that the polymerization of resin and wood is better at 11 percentresincontentand6 minutes of press time.
Composite wood products
Amir Nourbakhsh; Abdolrahman Hosseinzadeh; Ahmad Jahan latibari; Fardad Golbabaei; Abolfazl Kargarfard; Hossein Hosseinkhani
Abstract
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 ...
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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.
Composite wood products
Ahmad Jahan latibari; Abdolrahman Hosseinzadeh; Amir Nourbakhsh; Abolfazl Kargarfard; Fardad Golbabaei
Abstract
The influence of production variable such as residues moisture content at time of chipping or flaking, hardner and press time on properties of particleboard from date palm residues is investigated. Each variable was investigated at three different levels and a total of 24 combinations of variables were ...
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The influence of production variable such as residues moisture content at time of chipping or flaking, hardner and press time on properties of particleboard from date palm residues is investigated. Each variable was investigated at three different levels and a total of 24 combinations of variables were studied. The results of this investigation indicate that:
- Residues moisture content at the time of chipping or flaking affects both physical and mechanical properties of boards. MOR and MOE of board made from flakes produced by dry chipping and either wet or dry flaking was higher than others and its dimensional stability was better.
Chipping or flaking moisture did not affect IB significantly.
- Hardner consumption did not significantly influence the properties, but increasing hardner consumption to 3 percent of resin content (solid basis) improved board properties.
- Press time also did not influence board properties and for the production of 15 mm. boards, either 5 or 6 minutes press time can be used.
-For the production of boards to satisfy DIN requirement, following variable combination can be utilized: dry chipping - wet flaking, 3 percent hardner and 6 minutes press time.
