Physics and Mechanical Wood
mohammad najafianashrafi; ali Heidari; Hamed Jafarzadeh
Abstract
Background and goal: walnut tree (Juglans regia L.) are cultivated in many countries in Asia, Europe and United States. This tree has high resistance with beautiful pattern and are used in furniture industry, building panels, flooring and covering. Iran are ranked third in the world in the production ...
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Background and goal: walnut tree (Juglans regia L.) are cultivated in many countries in Asia, Europe and United States. This tree has high resistance with beautiful pattern and are used in furniture industry, building panels, flooring and covering. Iran are ranked third in the world in the production of walnut fruit after China and US. Thus, with considering high production of this tree in Iran and its diverse application in different industries, a comprehensive studding for physical and mechanical properties of this species in different regions of Iran seems necessary.Materials and methods: Walnut tree (Juglands regia L.) from two different regions, one from northeast (Mashhad) and the other from northwest (Maku) of Iran was selected for this study. Three trees from each region were selected randomly and cut with almost with the same diameter for physical and mechanical experiments. Samples also were cut from 2-4 meter from the ground. ISO 3129 and ASTM (D143-14) were used for doing physical and mechanical experiments respectively and at the humidity of 12%. Statistical analysis of data was performed using Graphpad prism version 8 and t-Test was performed for significant difference of data.Results: The average dry density of both Mashhad and Mako walnut wood was 0.625 and 0.579 g/cm3 respectively. There were a significant difference for both tangential shrinkage with values of 9.77 and 8.78 and volumetric shrinkage with measurement of 16.26 and 15.42 in Mashhad and Mako respectively. However, there was no significant difference for longitudinal and radial shrinkage in both walnut wood of the two regions. Walnut wood cut from Mashhad region showed higher physical and mechanical properties. The results of the mechanical characteristics of walnuts from two regions showed bending strength 100.54 and 87.61N/mm2 and elasticity modulus 10049.59 and 7504.21 N/ mm2 for Mashhad and Mako regions respectively which were significant. Results also showed not significant difference for compression parallel to the grain with values of 37.91 and 33.88N/mm2, for shear parallel to the grain with values of 9.15 and 8.95N/mm2, for Tensile strength parallel to the grain with 127.97 and 125.83 N/mm2, for Screw withdrawal strength in tangential values of 4031.01 and 3685.97N and Screw withdrawal strength in radial values of 4218.63 and 3915.03N and impact strength with the values of 27.81 and 25.24KJ/m2 for Mashhad and Maku regions respectively. Results also showed that the density of walnut wood in the two regions of Iran was similar to the those in Italy and eastern Europe but the mechanical properties of walnut tree such as bending strength and elasticity modules measured from Mashhad region was similar to the wone in turkey.Conclusion: The results showed that the physical and mechanical resistance of walnut wood located in Mashhad is higher than Maku wood, which was attributed to the higher dry density and the difference in weather conditions. Considering the appropriate mechanical resistance of walnut wood from both regions of Iran, this wood can be used in coating and furniture industries, building panels and flooring.
Pulp and paper
Jafar Ebrahimpour Kasmani; Ahmad Samariha; Alireza Khakifirooz
Abstract
This research was conducted with the aim of investigating the effect of two-layer coating of nano-polyurethane and nano-clay on the mechanical and physical properties of packaging cardboard with brown layer. For this purpose, brown layer cardboard with grammage of 127 was prepared and tested. To coat ...
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This research was conducted with the aim of investigating the effect of two-layer coating of nano-polyurethane and nano-clay on the mechanical and physical properties of packaging cardboard with brown layer. For this purpose, brown layer cardboard with grammage of 127 was prepared and tested. To coat the surface of the cardboard, it was first coated with nano-polyurethane and sprayed by a coating nozzle. Then the surface of the brown layer cardboard was covered with nano-clay to improve the performance of the coating material of the first treatment. Nano-clay coating was performed by a laboratory coating machine called barcoter. The coated cardboards were restrained and dried in the room for one day to stabilize the coating material on their surface. Then the samples were placed inside the freezer for 2 and 4 months and their properties were measured. The results showed that coating reduced water absorption. In the coated and frozen samples, an increase in thickness, smoothness of the surface and a decrease in water absorption and resistance properties compared to non-frozen control samples have been observed. Double coated samples showed very few pores. The thickness, smoothness of the surface and resistance to tearing in the machine cross direction of the double coated brown cardboard showed an increase of 13.7%, 75% and 3.8%, respectively, compared to the control sample. water absorption, resistance to bursting, resistance to tearing in the machine direction, resistance to tensile in the machine direction, resistance to tensile in the cross machine direction, resistance to ring crush test in the machine direction and resistance to ring crush test in the cross machine direction of the double-coated brown layer cardboard compared to the control sample, showed 107.20, 1.5, 34.3, 25.4, 24.3, and 4.7 percent decrease respectively.
Physics and Mechanical Wood
Mohammad Najafian ashrafi; Mohammad Ghorbanian Far; Esmail Rastbod; Mohammad Salehi; Mahdi Shamshiri
Abstract
The walnut tree is one of the most important species in Europe, Asia and Iran, which is used in various industries such as furniture, veneer, and construction due to its high resistance and beauty. In this research, walnut trees from two different geographic locations, one from the forests in the north ...
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The walnut tree is one of the most important species in Europe, Asia and Iran, which is used in various industries such as furniture, veneer, and construction due to its high resistance and beauty. In this research, walnut trees from two different geographic locations, one from the forests in the north of Iran (Noor) and the other in the west of Iran (Shahrkord), were selected. We studied physical properties including dry density, basic density, shrinkage, and mechanical properties including bending strength, modulus of elasticity, compression parallel to the grain, shear, tensile parallel and perpendicular to the grain, tangential and radial screw withdrawal strength and toughness. In this research, standards 3129 and ASTM D143-14 were used to perform physical and mechanical tests, respectively. The moisture content of all samples during mechanical tests was 12%. The average dry density of Noor and Shahrekord walnuts was 0.61 and 0.57 (g/cm3) respectively. The results of variance analysis showed that the characteristics and physical resistances of these two species were not significantly different except for dry density, radial, tangential and volumetric shrinkages. However, due to the higher density of Noor species, it showed higher mechanical resistance compared to the Shahrekord species.
Abolfazl Kargarfard; Reza Haji hassani
Abstract
The aim of this investigation was concentrated on the possibilty of untilizing corn cops residues in the production of particleboard. Two press temperatures of 170 and 180 oC, and four ratios of corn cop/poplar wood particles (100/0, 75/25, 50/50 and 25/75) in the corn layer of the boards and 100% poplar ...
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The aim of this investigation was concentrated on the possibilty of untilizing corn cops residues in the production of particleboard. Two press temperatures of 170 and 180 oC, and four ratios of corn cop/poplar wood particles (100/0, 75/25, 50/50 and 25/75) in the corn layer of the boards and 100% poplar wood particles in the surface layer were used. A combination of 16 treatments were reached and three laboratory boards for each treatment were made. Physical and mechanical properties of the boards were measured and statistically analyzed. The grouping of the averages were based on duncan multiple range test. The results indicated that the influence of the press temperature on both modulus of rupture and modulus of elasticity was statistically significante and boards produced applying 170 oC reached higher values. As the ratio of the corn cop particles in the particle mixture in core layer increased, both modulus of rupture and internal bonding deteriorated and the highest value were measured at 50/50 ratio of the particle in the core layer. The Boards which produced applying higher press temperature exhibited hgiher rate of thickness swelling . Lower ratios of the corn cop particle in the mixture of particles in the core layer improved the properties of the boards. So that the ratio of 50/50/ and 25/75 produced lower thickness swelling. The results of this research revealed that eventhough boards produced using corn cop particles did not produce comparable properties to the boards based on poplar particles, but it can be concluded that if 50/50 ratio of particles, press temperature of 170 oC is used for board making, the mechanical properties of the produced boards will meet the requirement of DIN specifications.
Composite wood products
Fardad Golbabaei; Kamyar Salehi; Reza Hajihassani
Abstract
In this study, the composition of bagasse composite was investigated using different amounts of bagasse particles. Bagasse and cement particles are manufactured at levels (5, 10 and 15%) and percentage of calcium chloride as cement accelerating additive at two levels (3 and 2%) based on cement dry weight. ...
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In this study, the composition of bagasse composite was investigated using different amounts of bagasse particles. Bagasse and cement particles are manufactured at levels (5, 10 and 15%) and percentage of calcium chloride as cement accelerating additive at two levels (3 and 2%) based on cement dry weight. Then, the mixture was poured into a mold measuring 15 8 18 8 8 cm and the excess water was removed from the bottom of the mold and initially weighed 10 kg on the specimens. The specimens were removed from the mold after 48 hours and kept in a glass saturated room at 90% humidity for 14 days and then finally dried in a laboratory environment. The bending strength and physical properties tests were performed on the specimens. The results showed that bagasse particles had a significant effect on bending strength and other physical properties. The bending strength was highest in boards made with 10% bagasse particles.
Pulp and paper
Iman Akbarpoor; Hossein Resalti; Ahmad reza Saraeyan
Abstract
In this study, Deinking of old newspaper was investigated by chemical and enzymatic methods. Chemical treatment was done using chemicals at different times of 10, 20 and 30 minutes, consistency of 10%, temperature of 50±1!C along with washing, flotation and combination of washing/flotation. While, ...
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In this study, Deinking of old newspaper was investigated by chemical and enzymatic methods. Chemical treatment was done using chemicals at different times of 10, 20 and 30 minutes, consistency of 10%, temperature of 50±1!C along with washing, flotation and combination of washing/flotation. While, Enzymatic treatment was accomplished at different concentrations of 0.025, 0.05, 0.1 and 0.2% of cellulase enzyme (on the basis of oven dried waste paper), pH range of 5-5.5, different times of 10,15 and 20 minutes, consistency of 10%, temperature of 50±1!C along with washing. The results comparison of optimum chemical and enzymatic treatments showed that, deinked pulp by chemical method had higher brightness and yellowness. Also, deinked pulp by chemical method resulted the papers with higher bulk, higher caliper and higher air resistance.
Composite wood products
Abolfazl Kargarfard
Abstract
Abstract: The application of corn stalks in the production of oriented strand board (OSB) is investigated. Corn stalks strands were produced in three sizes of 50, 75 and 100 millimeters length and dried to reach 2% moisture content. Oriented strand boards were made using either urea formaldehyde, melamine ...
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Abstract: The application of corn stalks in the production of oriented strand board (OSB) is investigated. Corn stalks strands were produced in three sizes of 50, 75 and 100 millimeters length and dried to reach 2% moisture content. Oriented strand boards were made using either urea formaldehyde, melamine formaldehyde and phenol formaldehyde resin, and two press temperatures of 175 and 185 ° C. OSB boards using poplar wood strands, 100 millimeters long were also produced as control samples. The results of strength measurements of the boards were statistically analyzed using factorial experiment and completely randomized block design. The grouping of the averages was based on Duncan Multiple Range Test. The results showed that the effect of the resin type on the flexural properties and internal bonding of the boards is statistically significant and boards produced using phenol formaldehyde resin exhibited the lowest modulus of rupture, modulus of elasticity and internal bonding strength. However, the adhesive type did not statistically influence the physical properties. The strand length also statistically influenced the board strength properties and boards made using poplar strands showed higher strength compared to corn stalks strands. The thickness swelling of the poplar OSB was almost twice the values of corn stalks OSB but the water absorption of these boards was lower than of corn stalks OSB. Press temperature adversely affected the modulus of rupture and elasticity, but higher press temperature improved the internal bonding strength. Higher press temperature increased the physical properties of the boards.
Composite wood products
Maryam Ghorbani; null null; farhad fooladian
Abstract
The Use of agricultural plants wastes as an alternative forest resources in the cellulose industry can be recommended due to the severe shortage of wood raw material and restriction of forest harvesting. The aim of current research was to investigate the effect of thermal modification on applied properties ...
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The Use of agricultural plants wastes as an alternative forest resources in the cellulose industry can be recommended due to the severe shortage of wood raw material and restriction of forest harvesting. The aim of current research was to investigate the effect of thermal modification on applied properties of composite made from sunflower stem flour-polypropylene. Thermal modification of sunflower stems was done at temperatures of 160, 180 and 200°C for 30 minutes and mixed with polypropylene in ratio of 30wt%. Test samples were prepared with maleic anhydride-grafted polypropylene as coupling agent by injection molding method. FTIR spectroscopy of sunflower stem flour confirmed the chemically changes due to thermal modification. More integration and uniform distribution, and less cavities were observed in the scanning electron micrographs of failure surface. The removal of hemicellulose of sunflower stem flour improved the thermal stability of composite, which thermal gravimetric analyzer (TGA) confirmed it with increasing in modification temperature up to 180°C. Modification at 200°C decreased thermal stability compared to other temperatures. Thermal modification leads to significant decrease in water absorption and improvement in bending and tensile properties due to hemicellulose degradation, increasing the crystallinity, loss of polarity, increased compatibility between the two phases of composite and uniform distribution of fillers in polymeric matrix. Notched impact strength of modified composites decreased due to better adhesion between lignocellulosic filler and polymer that facilitate the crack development along the interface.
Management and Economics wood
Mohammad Hadi Rezvani; Aisona Talaei; Hosseinali Rajabi Cham Heidari
Abstract
One of the main strategies to develop the extent of wood modification is using active functional groups in wood structure or the so-called impregnation with modified N-methylol compound. The aim of this study was to evaluate the physical properties of paulownia wood after modify with Polycrease ECR Cell ...
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One of the main strategies to develop the extent of wood modification is using active functional groups in wood structure or the so-called impregnation with modified N-methylol compound. The aim of this study was to evaluate the physical properties of paulownia wood after modify with Polycrease ECR Cell wall resin, to name modified dimethylol-dihydroxyethyleneurea (mDMDHEU). Physical test samples were prepared according to ASTM and EN standard and treated with pressure vessel method at two concentration levels; 15 and 25 percent of soluble resin. For polymerization, treated samples were heated in oven for 24-hour periods at 145 and 155 ºC respectively. Weight percent gain (WPG), bulking, water soaking, swelling, anti-swelling efficiency (ASE), leaching and contact angle were determined. High mDMDHEU concentration increased the weight gain and cell wall bulking. Highest weight percent gain (10.70%) and bulking efficiency (6.85%) in to levels of 25% were determined at 155 ˚C. In comparison with the unmodified wood, the mDMDHEU modified wood due to absorbed polymer enhancement exhibited improved dimensional stability and reduced water uptake, and maximum dimensional stability were determined in samples modified using to level 25% mDMDHEU containing solutions and curing temperature 155 ºC. Moreover, mDMDHEU treatment was resistant to leaching. Contact angle measurement further confirmed the improved hydrophobicity of wood after modification. Modification with mDMDHEU improved significantly the physical properties. The improve of the resistance of chemically modified wood exposed to can be attributed to the reduction of wood moisture, bulking of cell walls and cell cavities blocking affect to dominant reactivity mDMDHEU with cell wall wood polymer.
Composite wood products
Abolfazl Kargarfard
Abstract
Investigation on the Effect of Resin Gradient Consumption on Particleboard Properties Made Using Rose Flower Stalks Residues Abolfazl Kargarfard *Associate Prof., Wood and Paper Science and technology Research Division, Research Institute of Forests and rangeland, Tehran, Iran, kargarfard@rifr-ac.irAbstractThe ...
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Investigation on the Effect of Resin Gradient Consumption on Particleboard Properties Made Using Rose Flower Stalks Residues Abolfazl Kargarfard *Associate Prof., Wood and Paper Science and technology Research Division, Research Institute of Forests and rangeland, Tehran, Iran, kargarfard@rifr-ac.irAbstractThe potential of rose flower stalks for the production of particleboard was investigated. Three resin dosage gradients of 0, 2 and 4% (10% core: 10% surface; 9%core:11% surface and 8% core:12% surface) and three press times (3, 4 and 5 minutes) were selected as the variables and boards were produced. Then the mechanical and physical properties of the boards were measured and statistically analyzed. The results of modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB) measurements showed that as the resin dosage gradient increases, these properties improved and boards produced using either 2 or 4% resin dosage gradients generated the highest values. The effect of resin dosage gradient on these properties was statistically significant. As the resin dosage gradient increases, both thickness swelling after 2 and 24 hours immersion in water was improved. The effect of press time on thickness swelling after 2 and 24 hours immersion in water was also statistically significant and these properties were improved when 5 minutes press time was used The results indicate that if 2 or 4% resin dosage gradients and either 4 or 5 minutes press time is applied for the manufacturing of particleboards using rose flower stalks residues, the specification of the boards will meet the EN specification.Keywords: Particleboard, Rose flower stalks, Resin dosage gradient, Mechanical Properties, Physical Properties
Management and Economics wood
Farvahl Sobhani Oskouie; Maryam Ghorbani; Saeid mojtaba Amini nasab
Abstract
The objectives of this research determine for optimum condition modification with effect of 3-(trimethoxysilyl) propyl methacrylate on physical properties of Poplar wood-polymer were performed. Test samples from Poplar species were divided to five levels: control, Acidified Ethanol/Silan/110 ˚C, Acidified ...
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The objectives of this research determine for optimum condition modification with effect of 3-(trimethoxysilyl) propyl methacrylate on physical properties of Poplar wood-polymer were performed. Test samples from Poplar species were divided to five levels: control, Acidified Ethanol/Silan/110 ˚C, Acidified Ethanol/Silan/150 ˚C, Ethanol / Silan / 150°C and Silan/150°C in two levels with and without Benzoyl peroxide. Samples were impregnated with silan compound according to vacuum-pressure method in experimental cylinder. Weight percent gain of Silan/Et/BP/150 ˚C level by 24/40% had the maximum value were determined. Bulking efficiency and OH groups substituted in Silan/AEt/150 level with 6.81 % and 1.10 mol/gr, respectively compared with the other levels.Modification were resulted to improve water absorption and dimensional stability that maximum dimensional stability in contain initiator level were determined. In immersion-dry period test, the highest and lowest bulking efficiency in Silan/AEt/150 and Silan/Et/150 were reported. Maximum of weight loss in immersion-dry test was determined in Silan/AEt/110 with the 3.6% value.Key words: physical properties, 3-(trimethoxysilyl) propyl methacrylate, Asidified Ethanol, bulking efficiency
Management and Economics wood
Neda Esmaeeli; Maryam Ghorbani; pourya biparva
Abstract
This research was conducted to determine the optimal conditions for chemical modification of poplar wood with glutaraldehyde and its effect on the physical properties of products. Test samples were prepared according to the standard ASTM-D1037 and impregnated in the laboratory cylinders with Glutaraldehyde ...
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This research was conducted to determine the optimal conditions for chemical modification of poplar wood with glutaraldehyde and its effect on the physical properties of products. Test samples were prepared according to the standard ASTM-D1037 and impregnated in the laboratory cylinders with Glutaraldehyde at a concentration of 10% by using vacuum-pressure method. Modification reaction was done in two procedure. Heating first in the laboratory cylinder (Hydrothermal) for 4 hour and second in oven for 4 level 4,12,24,48 and 48hours. Weight percent gain of modified by hydrothermal and oven method was measured 2.10, 9.26, 10.02, 11.40 and 14.15% respectively. Chemical modification with glutaraldehyde by hydroxyl group's substitution, reduced the uptake of water and swelling of poplar wood. So that at the end of soaking in water the heating in the oven for 48 hours with minimum water absorption and dimensional changes in the 57.32 and 12.08 respectively, and highest bulking, ASE and ASE′ in 8.31,67 and 35.51% respectively was selected as the optimal level. This improvement compared to other modification levels demonstrates the forming of permanent Cross-linking of acetal that increased by Prolongation of the heating time.
Composite wood products
ghasem asadpour; seyyed majid zabihzadeh; Maryam Ghorbani; mahmoud davoudi
Abstract
Current research was conducted to investigate the effect of thermal modification on practical properties of horn beam bark flour-polypropylene composites. Wood plastic composites were divided in two levels of control and thermal modification, both levels included of 4 groups in bark fillers; 10, 20, ...
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Current research was conducted to investigate the effect of thermal modification on practical properties of horn beam bark flour-polypropylene composites. Wood plastic composites were divided in two levels of control and thermal modification, both levels included of 4 groups in bark fillers; 10, 20, 30 and 40%. Test samples prepared with maleic anhydride-grafted polypropylene as coupling agent by injection molding method. According to the results, bark flour increased water absorption, tensile and bending modulus. High proportion of bark fillers declined mechanical strength. Thermal modification significantly improved physical and mechanical properties of composite. Using lignocellulosic material flour bark hornbeam, tensile modulus and flexural modulus of composite material background had the highest improvement. In comparison between mechanical properties, impact resistance by adding flour bark had the greatest decrease. Thermal modification by increasing the crystallity, hemicellulose degradation, loss of polarity, increased compatibility between the two phases and uniform distribution of bark fillers in polymers, increased mechanical resistance.
Pulp and paper
Saleh Ghahrmani; Sahab Hejazi; Saeid Mahdavi
Abstract
In this research, capacity of cellulose nanofibers to reinforce of high yield kraft pulp produced (HYKP) from Populus deltoides clone 69-55 for making unbleached top kraft liner (UTKL) was investigated. The variable conditions of cooking were included the cooking time and temperature each one in two ...
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In this research, capacity of cellulose nanofibers to reinforce of high yield kraft pulp produced (HYKP) from Populus deltoides clone 69-55 for making unbleached top kraft liner (UTKL) was investigated. The variable conditions of cooking were included the cooking time and temperature each one in two levels. Sulfidity and active alkali were constant in the all cooking and liquid to wood ratio was 4 to 1. Optimum pulp was selected according to the pulp yield and kappa no. to reinforce by cellulose nanofiber. Then, it was refined by PFI mill beater to achieve 385 ml. CSF. The cellulose nanofiber was added in three levels (5, 10 and 15%) to HYKP, then mixed for 5 min. and handsheet made by special wire. The result indicated that 15% adding of cellulose nanofiber to high yield kraft pulp increased tensile index by 39%, burst index by 33%, tear index by 17.7%, bending stiffness index by 38% and ring crush tests (RCT) by 55.47%, respecting to the HYKP. In overall, it is recommended nanofiber adding to HYKP for UTKL making according to the yield and also physical and strength of reinforced pulp.
Composite wood products
Mehdi Kalagar; behzad baziyar; Habibalah Khademislam; Esmaeil Ghasemi; Amir homan Hemmasi
Abstract
In this paper, poly lactic acid (PLA)/ wheat straw fibers manufactured by twin screw extruder and molding compression have been studied. Wheat straw fibers were treated with trietoxymethel silane for better compatibility between two phases. Physical properties, tensile properties of the composites were ...
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In this paper, poly lactic acid (PLA)/ wheat straw fibers manufactured by twin screw extruder and molding compression have been studied. Wheat straw fibers were treated with trietoxymethel silane for better compatibility between two phases. Physical properties, tensile properties of the composites were analysis. The effect of the wheat straw fibers on the thermal properties of PLA has also been investigated in DSC experiments. The effects of silane treatment on the wheat straw fibers have been analyzed by FTIR. Scanning electron microscopy from samples surface were used for better study of water absorption and thickness swelling. Composites wheat straw fiber were treated shows signification lower water absorption and thickness swelling than composites PLA/ untreated wheat straw fibers. The lower amount of water absorption and thickness swelling occurred in the pure PLA. The existence crack and break occurred in the surface of PLA/ untreated wheat straw fibers composites after immersion in the water indicating higher water absorption and thickness swelling were in these samples. Wheat straw fibers were treated with silane due to better wetting and better linkage in the interfacial surface with PLA matrix showed higher tensile properties then PLA/ untreated wheat straw fiber composites. Differential scanning calorimeter test showed that with addition wheat straw fibers were treated to pure PLA the increased glass transition temperatures. The nucleating effect of wheat straw fibers, special treatment with silane cause to increased in the crystallization temperature composites than pure PLA which a positive effect showed on the degree of crystallization.
Composite wood products
Abdollah Najafi
Abstract
In this study, chemical treatments of rice husk flour on physical and mechanical properties of rice husk flour / high density polyethylene composites were studied. Rice husk was milled and its flour through the sieve of 60 meshes was selected for using. Initially, dried rice husk flour was subjected ...
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In this study, chemical treatments of rice husk flour on physical and mechanical properties of rice husk flour / high density polyethylene composites were studied. Rice husk was milled and its flour through the sieve of 60 meshes was selected for using. Initially, dried rice husk flour was subjected to chemical treatment with acetic acid and then, was mixed with powder of high density polyethylene at weight ratio of 60% filler loading in an internal mixer. After milling of mixed matreials, samples of composites were made by injection moulding method. Physical and mechanical properties of treated rice husk flour / high density polyethylene composites were compared to untreated composite and a composite including a PE-g-MA coupling agant (MAPE) that were produced in the same method. Dynamic Mechanical-Thermal Analyze (DMTA) of specimens in the temperature range of -50 to +150 ◦C were taken and storage modulus and loss modulus were measured. FT-IR spectra of chemical treatments of rice flour husks were also investigated to what extent changes in the functional groups being studied. Results of FT-IR indicated that the chemical treatment of rice husk led to a change of OH group absorbance on 3436 cm-1 and a peak in the region of 1741 cm-1 related to functional group of C=O. Results of tests also indicated that all of properties in composites including of treated rice husk flour with acetic acid were improved.
Management and Economics wood
Elham Hatamzadeh; Maryam Ghorbani; Poria bi parva
Abstract
In this research, effect of the alkaline precursors of soda and ammonia as reagent deposition of zinc oxide nanoparticles using hydrothermal method in structure and physical properties of poplar wood were investigated. The samples of physical test were prepared with dimensions of 2*2*2 cm3 according ...
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In this research, effect of the alkaline precursors of soda and ammonia as reagent deposition of zinc oxide nanoparticles using hydrothermal method in structure and physical properties of poplar wood were investigated. The samples of physical test were prepared with dimensions of 2*2*2 cm3 according to ASTM-D4446-05, and divided to three levels; control, Zncl2/NH3 and Zncl2/Naoh at 0.05M concentration and pH=10. Test samples were impregnated with salty precursor in the experimental cylinder using vacuum-pressure method, and in order to adjust the pH, soda and ammonia added. Due to the electron microscope images, change the type of precursor deposition, caused the different structure of ZnO nanoparticle. Retention of zinc oxide nanoparticles, density changes, water absorption, swelling and anti-swelling efficiency (ASE) were determined after synthesis. Retention of zinc chloride precursor with ammonia and soda acidity regulator was determined 4.43 and 1.71kg/m3 respectively. Water absorption increased at first hours of immersion, and then decreased. These treatments increased water absorption of wood. Least swelling and water absorption, and maximum ASE were measured in Zncl2/NH3 level.
Composite wood products
babak Nosrati; masih masoudifar; mohamad haghpanah
Abstract
Cordia (Sepestan in Persian) species (Cordia myxa L.) is in the borage family (Boraginaceae) and it is growing with geographical distribution in the moderate and tropical regions of Iran such as near the Persian Gulf, especiallyin Bandar Abbas and some places in Kerman and Sistan and Baluchestan region ...
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Cordia (Sepestan in Persian) species (Cordia myxa L.) is in the borage family (Boraginaceae) and it is growing with geographical distribution in the moderate and tropical regions of Iran such as near the Persian Gulf, especiallyin Bandar Abbas and some places in Kerman and Sistan and Baluchestan region but its anatomical characteristics have not been studied yet. In this study, some of the anatomical, chemical and physical properties of Sepestan wood in Iranshahr region in Sistan and Baluchestan Province were measured. Anatomical studies showed that this species has average diameter vessels, simple vascular perforation plate and intervessel pits alternate. Its ray xylems type is heterogeneous and contains abundant crystals. The wood tissue is parenchyma with abundant prismatic crystals and in the cross-section parenchyma was observed in gregarious and continuous formation. Average length, overall diameter, lumen diameter and wall thickness of the fibers were measured 1329, 33.5, 21.7 and 5.9 microns respectively. Also investigation of chemical characteristics showed that Sepestan wood has average cellulose 34.75, lignin 20.6, extractives soluble in acetone 7.88 and also 8.9 percent ash. The results also showed that the specific gravity of the wood is 0.4 and maximum volumetric swelling and shrinkage were 10.98 and 12.34 percent respectively.
Composite wood products
mahdi abasyan; asghar omidvar; mahdi mashkour; zinat farhadi
Abstract
This study seeks to investigate the possibility of producing polypropylene composite- cotton stalk flour with various percentages of cotton stalk flour. Determining the best treatment in terms of physical and mechanical properties and exploring the effect of using cotton stalks in the production of the ...
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This study seeks to investigate the possibility of producing polypropylene composite- cotton stalk flour with various percentages of cotton stalk flour. Determining the best treatment in terms of physical and mechanical properties and exploring the effect of using cotton stalks in the production of the composites were among the major objectives of this study. Six treatments consisting of Polypropylene, 40, 55 and 70 percent level of cotton stalks and two fillers (cotton stalks with and without barks) were developed. Maleic anhydride modified polypropylene (3% wt) was applied to each treatment. The mixing and granulation of the plastic and cotton silk flour was carried out using twin screw extruder model 4815. After preparing and shearing of samples, the mechanical properties of composites including tensile strength, rupture modulus and elasticity modulus were calculated in accordance with D-6109 and ASTM D-7031 standards. In addition, water absorption and thickness swelling tests were performed according to D-570-98 standard. The results showed that an increase in the flour of cotton stalk reduced the tensile strength and rupture modulus on the one hand, and increased the bending elasticity modulus on the other hand. In terms of the performance of the filler, there was a significant difference between values of rupture modulus and elasticity modulus at 95% level whereas this difference was not significant for tensile strength. Moreover, this difference was significant for values of water absorption and thickness swelling. The maximum tensile strength belonged to T4 with 40 percent of cotton stalk bark fibers.
Composite wood products
ELHAM MARZBAN MORIDANI; Mohammad Talaeipoor
Abstract
In this study, physical properties of composite produced using recycled polymer (polypropylene and polyethylene) filled with two types of paper mill sludge (sludge on the DAF and waste water sludge) were investigated. Three levels of paper sludge (15, 30 and 45 wt %) were used to produce composites. ...
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In this study, physical properties of composite produced using recycled polymer (polypropylene and polyethylene) filled with two types of paper mill sludge (sludge on the DAF and waste water sludge) were investigated. Three levels of paper sludge (15, 30 and 45 wt %) were used to produce composites. Haake machine was used to blend materials and to produce standard samples; injection molding system was utilized. Density, water absorption and thicknesses swelling of composites were measured. The increasing of both paper mill sludge (sludge on the DAF and wastewater sludge) to the recycled polyethylene and polypropylene increased the density of composites. But, comparing the data obtained from density measurement with literature showed that utilization of paper mill sludge produced relatively lower density and cost on the unit volume basis. Adding both paper mill sludge (sludge on the DAF and waste water sludge) increased water absorption and thicknesses swelling. The samples containing polypropylene and waste water sludge showed lower water absorption and thicknesses swelling compared with other composite.
Management and Economics wood
Lila Asadi khoramabadi; Abolghasem Khazaeian; Mohammad reza Masteri Farahani; Alireza Shakeri
Abstract
Heat treatment is one of the processes used to modify the properties of wood. The investigation of thermal treatment of wood has led to the improvement of heat treatment with vegetable oils. Heat treatment improves the dimensional stability and biological durability, but reduces the mechanical properties ...
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Heat treatment is one of the processes used to modify the properties of wood. The investigation of thermal treatment of wood has led to the improvement of heat treatment with vegetable oils. Heat treatment improves the dimensional stability and biological durability, but reduces the mechanical properties of wood. In this research, to improve the mechanical properties with other properties of wood, soybean oil modified with maleic anhydride was used for thermal treatment. Wood speciments were subjected to heat treatment soybean oil modified with maleic anhydride at two temperature (180 and 200° C ) and three time (2, 4 and 6 hours). Untreated beech was used as comparison for each treatment conditions. In this study, the effects of heat treatment on physical properties )water absorption and volumetric changes) and mechanical properties such as Bending strength) ISO 3133-1975(, Compression strength Parallel to grain) ISO 3787-1976 (and Impact bending) DIN 52189( were examined. The test results of heat-treated with modified soybean oil and control samples showed that physical and mechanical properties increases with heat treatment.
Composite wood products
Zahra Jahani lomer; Saeed Reza farrokhpayam; Mohammad Shamsian
Abstract
AbstracIn the past decade, artificial neural networks have been used as a powerful tool for modeling and prediction in many scientific fields. In this study, the feed-forward multilayer Perceptron (MLP) was utilized and trained by back propagation (BP) algorithm with Levenberg-Marquardt numerical optimization ...
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AbstracIn the past decade, artificial neural networks have been used as a powerful tool for modeling and prediction in many scientific fields. In this study, the feed-forward multilayer Perceptron (MLP) was utilized and trained by back propagation (BP) algorithm with Levenberg-Marquardt numerical optimization technique via Matlab software. Temperature of press (°C), mat moisture content (%) and press closing time (sec) were used as inputs, Water absorption (WA2, 24h), thickness swelling (TS2, 24h) and density were the outputs of neural network model. This technique will increase network versatility and decreases the effect of undesirable and weak data. The modeling and prediction was done based experimental data and the forecasting results were compared with real data. The efficiency of these techniques evaluated with statistical criteria of mean square error (MSE), root mean square error, (RMSE) and the correlation coefficient (R2). The results showed this ANN model could accurately describe the water absorption, thickness swelling after immersion for 2 and 24 hours, and density of particleboard
Composite wood products
Ghonche Rassam; Hamid Reza Taghiyari; Bratali Keshtegar
Abstract
Wood-composites are susceptible to fire due to their nature. Some research projects were therefore carried out to investigate potentiality of bentonite nanoparticles in improving fire-retarding properties in medium-density fiberboards (MDF); the present complimentary study aimed at determining the effects ...
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Wood-composites are susceptible to fire due to their nature. Some research projects were therefore carried out to investigate potentiality of bentonite nanoparticles in improving fire-retarding properties in medium-density fiberboards (MDF); the present complimentary study aimed at determining the effects of nanobentonite on physical and mechanical properties of MDF. Ten percent of urea-formaldehyde resin was used as adhesive in the matrix. Nano bentonite was added at 5 levels (%0 ,% 5 ,% 10 , %15 and %20) g/kg based on the dry weight of fibers. Bentonite nanoparticles were sprayed on the fibers after being mixed with the resin solution. Mats were hot-pressed for 4, 5, and 6 minutes at temperature of 170°C. Density was kept constant (75 g.cm-3) for all treatment. Results revealed that nano Bentonite did not improve the physical properties of water absorption, thickness swelling and mechanical properties of internal bonding (IB), modulus of elasticity (MOE), modulus of rupture (MOR). As to the other treatments, nano Bentonite consumption level of % 5 showed the lowest negative effect on the physical properties (water absorption, thickness swelling ) and treatment of 5% and %10 also less negative effect on the Mechanical properties (Modulus of rupture, Internal Bonding ). Treatment 20% is not recommended because it weakens the properties; moreover, the surface of fiberboards is not suitable. It was concluded that due to the fire-retarding improving effects, %5 of nano Bentonite is recommended as the optimum level for the industry.
Kamrava Pourhooshyar Ziabari; Javad Torkaman; Alireza Ashori; Yahya Hamzeh
Abstract
Physical and mechanical properties of lightweight cement blocks made from lignocelluosic fibers and rice husk ash (RHA) were investigated. The cement blocks were made using three types of natural fibers including old corrugated container (OCC), virgin kraft pulp and fiberboard fibers representing 25% ...
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Physical and mechanical properties of lightweight cement blocks made from lignocelluosic fibers and rice husk ash (RHA) were investigated. The cement blocks were made using three types of natural fibers including old corrugated container (OCC), virgin kraft pulp and fiberboard fibers representing 25% of dry weight of the block. Rice husk ash varied at 0, 25 and 50 WT% combined with 5 WT% CaCl2. Density, water adsorption and compressive strengths of blocks were measured and compared using a factorial experiment with two factors at three levels. The results showed the significant effect of fiber type on the properties of blocks. OCC fibers provided the highest density and compressive strength and had the lowest water adsorption. The density of blocks reduced at higher dosage of RHA varied from 0 to 50%, and the lowest water adsorption and highest compressive strength was obtained at 25% RHA charge. The interactive effects of raw material on the properties of cement blocks were significant and the optimum properties were obtained with OCC fibers and RHA at 25%. رص�" ��0#� pl� � همراه 5 درصد کلرید کلسیم در قالب طرح فاکتوریل دو عامله 3´3 و با سه تکرار، مجموعاً 27 بلوک سیمانی تهیه شد و دانسیته، مقدار جذب آب و مقاومت فشاری آنها مقایسه شد. تحلیل آماری مقاومت فشاری بلوکها نشان داد که اثر هر سه نوع الیاف در سطح 5 درصد معنیداری است. بهطوریکه بلوکهای ساخته شده از الیاف بازیافتی دارای بیشترین دانسیته و مقاومت فشاری و همچنین کمترین مقدار جذب آب بودند. البته اثر مقدار خاکستر سبوس برنج بر خواص بلوکها نشان داد با افزایش مقدار خاکستر از صفر درصد به 50 درصد، دانسیتة بلوکها کاهش مییابد، ولی بهترین نتایج جذب آب و مقاومت فشاری در میزان 25 درصد خاکستر سبوس برنج حاصل شد. بررسی اثر متقابل مواد استفاده شده بر خواص بلوکها نیز نشان داد که مقدار خاکستر سبوس برنج و نوع الیاف بر هم اثر معنیداری دارند و مطلوبترین بلوکها با استفاده از الیاف کاغذ بازیافتی و مقدار خاکستر سبوس به مقدار 25 درصد سیمان حاصل شد.
Ahmad reza Saraeian; Mozhdeh Mashkour
Abstract
Considering the problems initiated by sodium silicate on reducing the life expectancy of processing equipments and paper strength, recycling of old newspaper using Poly (acrylic acid), Sodium Salt Grafted to Poly (ethylene oxide) complex were investigated. The organic complex was used at 0.3, 0.5, 0.7, ...
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Considering the problems initiated by sodium silicate on reducing the life expectancy of processing equipments and paper strength, recycling of old newspaper using Poly (acrylic acid), Sodium Salt Grafted to Poly (ethylene oxide) complex were investigated. The organic complex was used at 0.3, 0.5, 0.7, 1, 2 and 3% levels (based on dry weight of waste paper) in deinking. The effect of various charges of the organic complex on the physical and optical properties of deinked pulp was studied and compared with the control (ONP deinked using 0.5% sodium silicate). The results of physical properties measurements showed that the lowest paper caliper (143.07 µm) and the highest density (0.43 g/cm3) were obtained by increasing the complex charge up to 2%. Also, the highest and lowest freeness was observed applying 3% (426.66 mL CFS) and 2% (350 mL CSF) organic complex respectively. These values were less than the freeness of the control sample. The results of optical properties analysis indicated that the brightness increased to 48.01% ISO and the yellowness was reduced to 6.23 % ISO by as the dosage of organic complex was increased up to 1%. The opacity of paper decreased as the organic complex charge increased. In general, the paper with higher density and brightness, lower yellowness and suitable opacity could be produced using 0.7- 2% Poly Acrylic Acid-Sodium Salt grafted to Polyethylene Oxide complex in deinking of old newspaper
