Aliakbar Yazdi meymand; Ali Khaki; mohammad ghofrani
Abstract
Sandwich panels are one of the most advanced forms of composite structures that are widely used. The objective of this study was to investigate the effect of three types of resin: urea formaldehyde (UF), melamine formaldehyde (MF) and the combination of urea formaldehyde + melamine formaldehyde (UF + ...
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Sandwich panels are one of the most advanced forms of composite structures that are widely used. The objective of this study was to investigate the effect of three types of resin: urea formaldehyde (UF), melamine formaldehyde (MF) and the combination of urea formaldehyde + melamine formaldehyde (UF + MF) two core layer densities (400 and 500 kg/m3) on physical and mechanical properties of sandwich panels made of palm leaves waste. Pressure temperature, pressure and time for all panels were 175 °C, 35 kg /cm2 and 9 minutes, respectively. The final thickness of all panels was the same and equal to 25 mm. Physical and mechanical properties include; Water absorption (WA), thickness swelling (TS), modulus of rupture (MOR), modulus of elasticity (MOE), impact bending strength (IBS) and internal bonding (IB) were performed on the samples. The results showed that there was a significant (p<0.05) difference between the values of different treatments at the level of 95%. Physical properties (except thickness swelling) and mechanical properties with a density of 500 kg/m3 improved. The use of MF and UF + MF resins significantly improved the physical and mechanical properties of sandwich panels due to its high adhesive quality.
Mechanical conversion of wood and wooden fittings
Mostafa Poozesh; Hamid Reza Mansouri; babak Nosrati; Alireza Samzadeh
Abstract
This objective of this investigation was to modify and improve the water resistance of urea formaldehyde (UF) bonded particleboard adding Boric acid to the resin. Four levels (1, 2, 3 and 4) of boric acid based on the dry weight of the bonder were added to the UF resin. Then these mixtures were ...
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This objective of this investigation was to modify and improve the water resistance of urea formaldehyde (UF) bonded particleboard adding Boric acid to the resin. Four levels (1, 2, 3 and 4) of boric acid based on the dry weight of the bonder were added to the UF resin. Then these mixtures were used to produce particleboard. Physical and mechanical properties were examined according to the ASTM, D1013-04. The results showed that the using of this additive increased the water absorption and thickness swelling resistance after 2 and 24 hours immersion in water. Also using this additive increased the internal bonding of the boards after 24 hours after immersion in water, compared to the control sample but in the case of dry samples, the internal bonding decreased compared to the control sample. However it was not lower than standard value. As the Boric acid levels increased to 2 percent, bending strength of the samples was increased compare to the control sample and after this level it was decreased. Also with increasing the levels to 4 percent, modulus of elasticity of boards were increased compare to the control sample
Composite wood products
Sajad Akbari; Morteza Nazeryan; Saeid reza Farokhpayam; Babak Nosrati sheshkal
Abstract
In this study the possibility of using canola stalks mixed with poplar wood in the manufacture of particleboard was investigated. Weight ratio of canola particle to poplar particles at five levels (98, 93/75, 87/50, 81/25, 77%), the weight ratio of the urea-formaldehyde/melamine formaldehyde resin as ...
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In this study the possibility of using canola stalks mixed with poplar wood in the manufacture of particleboard was investigated. Weight ratio of canola particle to poplar particles at five levels (98, 93/75, 87/50, 81/25, 77%), the weight ratio of the urea-formaldehyde/melamine formaldehyde resin as a adhesive at five levels (23, 18/75, 12/50, 6/25, 2%) and moisture content of matt at five levels (10, 12, 15, 18, 20%) were selected as production variables. Mechanical properties of boards consist of MOR, MOE and IB was tested. According to the results, with increasing the canola stalks/poplar particle ratio MOR and MOE of the boards decreased, but all of the values obtained from treatments were higher than standard. Interaction effect analysis of variables showed that the increasing the ratio of melamine formaldehyde/urea formaldehyde resin decreased the bending strength, while the increasing the moisture of mat increased MOR and MOE. IB values of all treatments are lower than the standard. According to the results of response surface methodology (RSM) and interaction effect between studied variables on the mechanical properties of the panels, the best situation for producing the panels was selected as: weight ratio of 84/32 for canola/poplar particle, ratio of 6/25 for UF/MF resin and moisture content of 12% for mattress.
Kazem Dosthosseini; robab ghafari
Abstract
In this research, the effect of increasing content of urea to urea-formaldehyde adhesive on physical and mechanical properties of poplar wood particleboard was investigated. The content of urea added to the adhesive four levels (zero, 4.1, 8.2 and 16 % based on the solid content of adhesive) and ...
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In this research, the effect of increasing content of urea to urea-formaldehyde adhesive on physical and mechanical properties of poplar wood particleboard was investigated. The content of urea added to the adhesive four levels (zero, 4.1, 8.2 and 16 % based on the solid content of adhesive) and two press temperatures of 170 and 180° C as the variable factors were selected. Boards with density of 0.63 gr/cm3 and 10% of the adhesive dosage were made. Mechanical properties including modulus of rupture (MOR), internal bond (IB) and physical properties including water absorption and thickness swelling were measured. Results showed that urea addition to urea formaldehyde adhesive improved the mechanical strengths of the board especially internal bonding reduced the water absorption and thickness swelling. Also, the impact of press temperature on mechanical and physical properties of boards was noticeable and boards produced applying press temperature of 170° C were superior.
Pulp and paper
Hamd Unesi kord khalili; Mehran Jalilvand; Rabi Behroz
Abstract
The purpose of this study was to investigate effects of different loading levels and addition of urea formaldehyde and polyethylene on the creep behavior of composites made from wastes of OCC recycling mills. The composites manufactured by hot press method and three-point ...
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The purpose of this study was to investigate effects of different loading levels and addition of urea formaldehyde and polyethylene on the creep behavior of composites made from wastes of OCC recycling mills. The composites manufactured by hot press method and three-point bending test performed before creep test. In general, the results showed positive effects of additive materials such as urea formaldehyde and polyethylene on the creep behavior of the composites. While adding UF and PE decreased primary and final creep as well as return deformation percentage of the composites. Also the obtained results indicated that remaining creep had higher sensitivity to loading levels compared to primary and final creep. Also the increase of the load levels from 20% to 30% led to an increase in creep content of the composites.
Management and Economics wood
Kazem Dost Hosseini; Maryam Ghorbani kobandeh; Samira Mohammad ali bighi; Alinaghi Karimi
Abstract
This research was conducted to evaluate the effects of acetylation and the resin type on three layered populus particleboard against white-rot fungus, Trametes versicolor. Populus particles were acetylated at three levels of acetyl content (WPG of 0, 8.39% and 17.27%). In manufacturing of single and ...
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This research was conducted to evaluate the effects of acetylation and the resin type on three layered populus particleboard against white-rot fungus, Trametes versicolor. Populus particles were acetylated at three levels of acetyl content (WPG of 0, 8.39% and 17.27%). In manufacturing of single and three layered boards with acetylated particles two type of resin, urea formaldehyde and isocyanate( as adhesives) were employed.
The results indicated positive role of acetylation in reducing decay rate. Weight loss of boards made from isocyanate was less than the boards containing urea formaldehyde resin. Also, three layered boards showed higher resistance against the fungus compared with single layered boards.
Kazem Dosthosseini; Bita Moezi poor
Abstract
Utilization of date palm and kenaf fibers for reinforcement of plywood was investigated and after making plywood with layers of horn beam wood (Carpinus betulus), physical and mechanical properties were analyzed. Variables were the type of fiber (kenaf and date palm), the type of filler (wheat flour ...
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Utilization of date palm and kenaf fibers for reinforcement of plywood was investigated and after making plywood with layers of horn beam wood (Carpinus betulus), physical and mechanical properties were analyzed. Variables were the type of fiber (kenaf and date palm), the type of filler (wheat flour and waste paper) and the content of resin (150 and 200 g/m2). The results of this study show that utilization of kenaf and date palm fibers was effective in improvement of physical and mechanical properties of plywood. The mean of specific gravity for reinforced plywood with kenaf and date palm fibers was 0.723 and 0.739 g/cm3 respectively and specific gravity of control was 0.656 g/cm3. The least water absorption and thickness swelling were about reinforced boards with kenaf fibers and 200 g/m2 resin with wheat flour filler .The reinforced boards with kenaf fibers and 150g/m2 resin with wheat flour filler have the best mechanical properties. So the kenaf fibers for reinforcement of properties of plywood were better than date palm fibers and the utilization of wheat flour in manufacture of these boards had better results compared to waste paper filler.
Composite wood products
Kazem Dost hosseini; Bita Moezipoor
Abstract
The possibility waste paper (writing paper and newsprint) and old corrugated carton (OCC) utilization as a filler of urea formaldehyde resin onplywood manufacturing was investigated. Theeffect of type of filler as a variable factor on applicable properties i.e. water absorption and swelling after 2 and ...
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The possibility waste paper (writing paper and newsprint) and old corrugated carton (OCC) utilization as a filler of urea formaldehyde resin onplywood manufacturing was investigated. Theeffect of type of filler as a variable factor on applicable properties i.e. water absorption and swelling after 2 and 24 hours, bending strength parallel and perpendicular to grain and shear strength on the interface was evaluated and the results were analyzed. The results of this study showed that utilization of waste paper and old corrugated carton as the filler decreased the water absorption and swelling and improved their mechanical properties. Since this materials caused to promote adhesion and improved the urea formaldehyde resin bond, it can be inferred that waste paper and old carton can act as an extender on the resin binding process.
Alireza Mohammadi; Taghi Tabarsa; Mohammad Tasooji
Abstract
The effect of amino silane coupling agent on properties of wheat straw boards produced by UF and MF resins, was investigated in this study. For producing the straw boards small particles of straw were used . The results showed that adding 2 and 5 percents of silane had significant effect on improvement ...
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The effect of amino silane coupling agent on properties of wheat straw boards produced by UF and MF resins, was investigated in this study. For producing the straw boards small particles of straw were used . The results showed that adding 2 and 5 percents of silane had significant effect on improvement of boards properties. This improvement might be due to surface treatment of wheat straw particles with silane coupling agent by increasing the bondability between straw particles and resin. The more amine groups in Melamine Formaldehyde resin compare to urea formaldehyde resin , lead to an improvement in bending strength and thickness swelling.
Aliakbar Ramtin; Behnaz Dadkhahi tehrani; Kazemi Dossthoseini
Abstract
In this study, effects of press temperature and press time on the physical and mechanical properties on the OSB has made from Aspen were investigated. Two levels of press temperature 175ºC and 185ºC and two levels of press time 5 min and 6 min were applied as variables for manufacturing boards. ...
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In this study, effects of press temperature and press time on the physical and mechanical properties on the OSB has made from Aspen were investigated. Two levels of press temperature 175ºC and 185ºC and two levels of press time 5 min and 6 min were applied as variables for manufacturing boards. Mechanical and physical properties such as bending strength, internal bond, water absorption and thickness swelling were measured. results showed that, increase in press temperature and press time causes significant increase on bending strength, internal bond, water absorption and thickness swelling. The best boards were made of press temperature of 185ºC and press time 5 minutes.
Composite wood products
Hossein Hosseinkhani; Abdolrahman Hosseinzadeh; Fardad Golbabaei; Amir Nourbakhsh; Nayeralsadat Sadraei; masoudreza Habibi
Abstract
In this study, the effect of board type, press time and resin content on the strength of particleboard have been evaluated. The boards made for this study contained bagasse and logging residues of Eucalyptus wood particles at a 50 to 50 ratio and employed Urea formaldehyde (UF) resin as the binder. Variable ...
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In this study, the effect of board type, press time and resin content on the strength of particleboard have been evaluated. The boards made for this study contained bagasse and logging residues of Eucalyptus wood particles at a 50 to 50 ratio and employed Urea formaldehyde (UF) resin as the binder. Variable factors are as follows:- type of board; single layer, three layer- press time; 5 , 6 , 7 , minutes- resin content; 9 , 10 , 11 percentThree boards' were manufactured for each combination of variables. Samples of all the boards made were tested by the methods described in DIN 68763 standard to obtain mean values of bending strength, and internal bond strength (LB). In addition samples of each type of board were tested for thickness swelling after immersion in water for 2 hours and 24 hours respectively.The results of this study show clearly that three layer particleboard has significantly higher bending strength than single layer, but single layer boards have better properties from the physical aspect.
Increasing the content of U.F resin from 9 per cent to 10 per cent was found to reduce the thickness swelling, and tended to improve the strength properties of the board, in both single layer and three layer boards. Press time has significant effect on bending strength and I.B Highest MOR and MOE were observed on three layer board pressed for 7 minutes.
