Management and Economics wood
Reza Jazayeri; Reza Hajihassani; Sedighe Nazari
Abstract
The main purpose of this study was to evaluate the effect of hydrothermal treatment with boric acid impregnation on some physical and mechanical characteristics and fire resistance of poplar (Populus nigra) and radiata pine (Pinus radiata) wood. In this study, two times of 60 and 90 minutes with two ...
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The main purpose of this study was to evaluate the effect of hydrothermal treatment with boric acid impregnation on some physical and mechanical characteristics and fire resistance of poplar (Populus nigra) and radiata pine (Pinus radiata) wood. In this study, two times of 60 and 90 minutes with two temperatures of 150○C and 180○C were used for the hydrothermal treatment, and boric acid with concentrations of 1, 3 and 5% dissolved in water used for the impregnation treatment. The measurement of the characteristics, including bending strength, impact resistance, volumetric swilling and fire resistance (weight loss due to fire) were done by ASTM-D143, ASTM-D256, ASTM 4446-2002 and ISO 11925 standards, respectively. About fire resistance, 5% boric acid treatment showed the least weight loss due to burning in the wood of two species. As a result of the hydrothermal treatment alone, the fire resistance was even lower than the control. In this regard, the combination of hydrothermal treatment with boric acid treatment resulted in results close to those of hydrothermal with boric acid treatment. Positive effect of hydrothermal treatment on the improvement of dimensional stability, is considered as one of the results of the present study. The temperature of 180○C with a time of 90 minutes reduced the swelling of poplar and radiata pine by about 36.8 and 42%, respectively. Regarding impact resistance, the effect of hydrothermal treatment on the wood of both species and the effect of boric acid treatment on radiata pine wood were negative. Hydrothermal treatment at a temperature of 180○C and with a time of 90 minutes decreased the impact resistance by 28.2% in the wood of both species, and 5% boric acid treatment caused a 13.3% decrease in this property in radiata pine wood.
Reza Ghaffari Sani; Foroogh Dastoorian; seyed Majid Zabihzadeh; Mohammad Tasooji
Abstract
In recent years, plant oils usage as matrix in natural fiber reinforced polymer composites, has been considered because of increasing environmental concern. In the present research work, acrylated epoxidized soybean oil combined with maleic anhydride and styrene as a matrix and wheat straw flour as filler ...
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In recent years, plant oils usage as matrix in natural fiber reinforced polymer composites, has been considered because of increasing environmental concern. In the present research work, acrylated epoxidized soybean oil combined with maleic anhydride and styrene as a matrix and wheat straw flour as filler was used for making a relatively biodegradable composite. In order to find the optimum synthesis time of resin, during reaction of maleic anhydride with acrylated epoxidized soybean oil, three time level of 60, 90 and 120 min, polymer was prepared and cross link density was determined with “solvent swelling” method. The optimum synthesis time of resin was obtained 90 min. Afterwards, maleated acrylated epoxidised soybean oil was mixed with 25% of styrene and 60 mesh wheat straw flour in three weight ratio of 20, 30 and 40% manually. The combination of resin and wheat straw flour was poured in a steel mold and pressing was applied manually. The die was placed in an oven at temperature of 140oC for one hour. Infrared spectroscopy, Thermogravimetric analysis tensile and impact test was conducted to evaluate and analyze the physical and mechanical properties of the resulted composite. Infrared spectroscopy results showed ether bond formation between hydroxyl groups of wheat straw and carbonyl groups of resin. Water absorption test results showed no statistical difference between water absorption values of three loading of wheat straw till 144 hours of immersion, however at 168 hours of immersion, water absorption values were increased with increase of wheat straw loading. There was no statistical difference between thickness swelling values of composites with different wheat straw loading. With increasing wheat straw loading, tensile strength and modulus was increased significantly. Also the impact strength increased as an increase of wheat straw loading.
Composite wood products
Behzad Ghasemi; Farshid Faraji; Sahab Hedjazi
Abstract
Abstract In this research, the effect of using natural poly lactic acid polymer and the amount of MAPP coupling agent on the physical and mechanical properties of composite manufactured by sunflower stem flour was studied. For this purpose, three levels of PLA polymer including 50, 60 and 70% and tow ...
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Abstract In this research, the effect of using natural poly lactic acid polymer and the amount of MAPP coupling agent on the physical and mechanical properties of composite manufactured by sunflower stem flour was studied. For this purpose, three levels of PLA polymer including 50, 60 and 70% and tow levels of MAPP including 4 and 6 percent based on dry weight of polymer were used as variables. Then, the physical and mechanical properties of the test specimens including dimensional stability, resistance and tensile modulus, resistance and flexural modulus and impact resistance were measured. The results showed that increasing the amount of PLA polymer and reducing the share of sunflower stem flour and increasing MAPP up to 6 percent, increased the flexural, tensile and impact resistances and improved dimensional stability of the composites. But in contrast, the tensile and bending modulus of composites were reduced. However, by reviewing the results, it was found that the physical and mechanical properties of the composites made with this polymer and the particles of sunflower stem flour were competitive with other composites made with other chemical polymers and in some cases it was better than them.
Composite wood products
Hamid Ibaghi esfahani; Mehdi Kalagar; Hossein Sepehridad
Abstract
To study the tensile properties and impact strength in Wood Plastic Composites (WPC) polypropylene as a matrix and teada pine sawdust as reinforcement / filler is used. Ethylene / propylene / Diane / monomer (EPDM) as modified impact resistance with 10, 20 and 30 percent improved impact resistance and ...
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To study the tensile properties and impact strength in Wood Plastic Composites (WPC) polypropylene as a matrix and teada pine sawdust as reinforcement / filler is used. Ethylene / propylene / Diane / monomer (EPDM) as modified impact resistance with 10, 20 and 30 percent improved impact resistance and maleic anhydride grafted polypropylene (MAPP) at a rate of 3 percent as a fasteners to improve response and polymers and fillers were added to the composite. To evaluate the fracture surface of a structure scanning electron microscope (SEM) was used. The apply of 10 % elastomer and 3 % coupling agent cause to improved of tensile properties and the use of higher levels of elastomer (20 and 30 %) has shown a decreasing trend in these properties. The results showed that PP matrix by adding sawdust to a significant reduction in impact strength of composite than pure PP is observed. An EPDM additive used in all contents of composites PP / sawdust has improved impact strength. Simultaneous use of EPDM and MAPP used a positive effect in tensile properties and impact strength. The apply of EPDM (30%) and 3% (MAPP) has demonstrated the highest level of impact strength. SEM images show that the use of EPDM and MAPP composites will improve the connection of interface.
Composite wood products
Hamid Aibaghi esfahani; Mehdi Kalagar; Elham Marzban moridani
Abstract
In this study, mechanical properties of high density polyethylene (as matrix) and olive mill sludge (as filler / reinforcement) composites were investigated. There levels of paper sludge (15, 30, 40 and 50 wt %) were used to produce composites. The effect of maleic anhydride grafted polyethylene (MAPE) ...
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In this study, mechanical properties of high density polyethylene (as matrix) and olive mill sludge (as filler / reinforcement) composites were investigated. There levels of paper sludge (15, 30, 40 and 50 wt %) were used to produce composites. The effect of maleic anhydride grafted polyethylene (MAPE) as coupling agent on the mechanical properties composite was investigated and then, these composites (with coupling agent) were compared with composites without coupling agent. For blending materials from extruder and produce of mechanical standard sample from injection molding were used. Mechanical properties containing tensile properties (modulus of elasticity and tensile strength) and impact strength were studied. The result of obtaining from modulus of elasticity showed that with adding olive mill sludge to the polyethylene cause to signification increasing in modulus of elasticity were compared to pure polyethylene. Tensile strength composite increasing with adding olive mill sludge compared to pure polyethylene but maximum measure of tensile strength related to composites contain 30% olive mill sludge and coupling agent. Also adding 15% olive mill sludge to polyethylene cause to improved impact strength in compared pure polyethylene, but with adding more olive mill sludge (30, 40 and 50%), impact strength in composites were decreased. The used of coupling agent in the total manufactured composite cause to improved in impact strength of composites. The addition of a coupling agent (MAPE) to the composition resulted in an increase in mechanical properties of the composites that indicating enhanced matrix–olive mill sludge interfacial adhesion.
Vahid reza ُSafdari; Nima Eskini; Ajang Tajdini; Vlima Bayramzadeh
Abstract
Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: ...
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Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: inside of soil and exposed one can reveal effects of soil erosion on wood anatomical properties of root. So many roots and barks of trees in inside of soils and exposed have been sampled and many micro-sections prepared by microtome and anatomical properties were investigated. Results showed that wood roots under soil conform of one row of late-wood and by exposing the lumen area of tracheids in early-wood and late-wood were decreased and the cells appear thicker and late-wood portion increased. The axial parenchyma inclusion of dark resins in exposed roots observed frequently. Meanwhile by exposing of roots the thickness of bark decreased and the thickness of phloem and periderm in exposed root is not as wide as normal roots.
Composite wood products
Amir Nourbakhsh; Taghi Tabarsa; Abolfazl Kargarfard; Fardad Golbabaei
Abstract
Laminated veneer lumber (L. V. L) manufactured from Maple and Alder wood is investigated. Three levels of layer thicknesses of 2, 3 and 4mm. were investigated. Bending strength (MOR and MOE), CompressionThe results of this investigation indicated that laminated wood strength of samples produced from ...
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Laminated veneer lumber (L. V. L) manufactured from Maple and Alder wood is investigated. Three levels of layer thicknesses of 2, 3 and 4mm. were investigated. Bending strength (MOR and MOE), CompressionThe results of this investigation indicated that laminated wood strength of samples produced from Alder layers are superior to Maple. Statistical analysis of the results showed that the effect of wood species on strength properties was significantly different at 99% level. Layer thicknesses also showed significant effect on strength increasing layer thicknesses from 2 to 4 mm. caused a reduction on MOE and improved impact properties.The results of this investigation also showed that Alder layers at 4 mm. Is superior to Maple layers in impact properties.
