Composite wood products
Reza Jazayeri; Saeed Kazemi Najafi; Habibollah Younesi
Abstract
This study aimet at to use modified graphite materials as a multifunction additive in the UF resin for improving the properties of medium density fiberboard (MDF). For this purpose expanded graphite EG was synthesized from graphite using the Tsai et al (2011) method. Then, as-synthesized EG was intercalated ...
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This study aimet at to use modified graphite materials as a multifunction additive in the UF resin for improving the properties of medium density fiberboard (MDF). For this purpose expanded graphite EG was synthesized from graphite using the Tsai et al (2011) method. Then, as-synthesized EG was intercalated with manganese dioxide by Schwarz et al (1995) method and converted to MnO2-EG. Any additive was added to the urea formaldehyde resin in three doses of 1, 2 and 3% to make the relevant MDF panels with 750 kg/m3 nominal density. During the pressing time, the tT100oc parameter (time to reach temperature100○C) of the middle layer of the board under the influence of the additive was determined by a chromium-nickel-based thermocouple. The treatment of MnO2-EG3 (amount of 3% modified expanded graphite) showed the greatest effect in reducing tT100°C of the middle layer of the board by 22%. In addition, the elastic modulus increased by 68% as a result of this treatment. In addition, the elastic modulus increased by 68% as a result of this treatment. G and EG additives showed a higher degree of internal adhesion than that of MnO2-EG additive. In this regard, EG2 and EG3 treatments showed a 42% increase in internal adhesion and G2 treatment showed a 40% increase in internal adhesion. The effect of EG2 treatment in improving SW24 was greater than other treatments, so that it caused a 19% decrease compared to the control.
Composite wood products
Laya jamali rad; saeed Narooei
Abstract
The purpose of this study was to investigate the possibility of using tobacco stalk and industrial wood particles in particleboard industry as a waste material that is not consumed and discarded and has a low price, followed by a reduction in production costs from the way of choosing this raw material ...
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The purpose of this study was to investigate the possibility of using tobacco stalk and industrial wood particles in particleboard industry as a waste material that is not consumed and discarded and has a low price, followed by a reduction in production costs from the way of choosing this raw material was of low value. For this purpose, the particles of tobacco stalk and industrial wood particles with different ratios of 0:100, 30:70 and 60:40, using the amount of adhesive used 12% and 14% (based on the dry weight of the wood chips) and the press time of 5 minutes for the construction of the board was considered. Physical and mechanical properties including thickness swelling after 2 and 24 hours immersion in water and bending strength (MOR), modulus of elasticity (MOE) and internal bonding (IB) were measured and all data were statistically analyzed. According to the results of this study, the increase in tobacco stalk particles resulted in increased thickness swelling after 2 and 24 hours immersion in water and reduced bending strength, modulus of elasticity and internal bonding, but all boards had a European standard (EN). Increasing the amount of resin also had a significant effect on all the properties of the boards and improved the properties. In a general conclusion and by comparing the properties of the boards produced with the European standard (EN), showed that using 60% tobacco stalk and 12% urea formaldehyde resin can be produced particleboard with the desired properties. This is a positive result of using tobacco stalk as a type of agricultural residue and, consequently, the prevention of environmental pollution caused by the burning of these compounds.
Mohamad Tasoji; Taghi Tabrsa; Alireza Mohammadi
Abstract
For making wheat straw particleboards, different mixtures of UF and MF resins were used. The ratio of UF : MF was 0:100,75:25,50:50,25:75 and 100:0 based on weight of resin and boards densities were set to 0.7 . The physical and mechanical properties such as Thickness Swelling(TS)(after 2 and 24 hours), ...
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For making wheat straw particleboards, different mixtures of UF and MF resins were used. The ratio of UF : MF was 0:100,75:25,50:50,25:75 and 100:0 based on weight of resin and boards densities were set to 0.7 . The physical and mechanical properties such as Thickness Swelling(TS)(after 2 and 24 hours), Internal Bonding(IB) , Modulus Of Elasticity(MOE) ,Modulus Of Rupture(MOR) were determined and compared to EN 312-4 standard. The highest amounts of IB ,MOR and MOE are from the boards that were made from 50:50 (UF:MF) . All of The boards MOE and MOR amounts of all treatments except treatment 100:0 (UF:MF) were in range of EN 312-4 standard but the IB amounts were not. The TS amount was improved in the boards with more MF content but it was not in EN 312-4 range. Due to the thin waxy layer that covers the outer most layer of wheat straw surface, the non polar structure of this layer brings incompatibility between polar resins and wheat straw particles and this incompatibility will result in low physical and mechanical property for wheat straw particleboards. Also due to low porosity of waxy layer, the distribution of formaldehyde polar resins on straw particles surface, not well occur and this itself is an important factor in decrease of physical and mechanical resistance in wheat straw particleboards.
Composite wood products
Laya Jamalirad; Fereshteh Kor; Farshid Faraji; Sahab Hedjazi
Abstract
In this research, the manufacture of particleboard using lignocellulosic residues including wheat straw and tobacco stalks mixed with industrial wood chips were studied. The variable factors included the mixture of wheat straw and tobacco stalks with industrial wood chips in four levels 0/100, 20/80, ...
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In this research, the manufacture of particleboard using lignocellulosic residues including wheat straw and tobacco stalks mixed with industrial wood chips were studied. The variable factors included the mixture of wheat straw and tobacco stalks with industrial wood chips in four levels 0/100, 20/80, 40/60 and 60/40 (In any combination, according to the desired levels, tobacco stalks and wheat straw were used equally) and the amount of urea formaldehyde resin was at two levels 12 and 14% of the dry weight of the wood chips. The results showed that by increasing the mixture of wheat straw and tobacco stalk up to 60 percent, the physical and mechanical properties of the boards decreased significantly. But increasing the amount of adhesive consumption up to 14 percent had a positive impact on the physical and mechanical properties of the boards and improved internal bonding, bending strength and modulus of elasticity and dimensional stability of the boards. It means that by increasing the use of this type of wastes up to 40 percent with an increase in the amount of UF adhesive up to 14% can be produced the boards with the mechanical properties at standard level.
Composite wood products
Samira Brzali; Laya Jamalirad; Farshid Faraji; Sahab Hejazi
Abstract
In this research with the aim of using a natural component, renewable and environmentally friendly which is not environmental pollution, the physical and mechanical properties of plywood manufactured by populous with urea formaldehyde resin and silk cocoon were studied. For this purpose, silk cocoon ...
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In this research with the aim of using a natural component, renewable and environmentally friendly which is not environmental pollution, the physical and mechanical properties of plywood manufactured by populous with urea formaldehyde resin and silk cocoon were studied. For this purpose, silk cocoon was used as filler and reinforcement for four levels of 0, 10, 20 and 30 percent according to dry weight of urea formaldehyde resin. The physical and mechanical properties of samples including water absorption and thickness swelling after 2 and 24 hours immersion in water, bending strength parallel and perpendicular to the surface layer grain and shear strength were measured. The results show that increasing the amount of silk cocoon, decreased water absorption and thickness swelling after 2 and 24 hours immersion in water and increased bending strength parallel and perpendicular to the surface layer grain and shear strength. So that, using 30 percent of silk cocoon, dimensional stability, bending strength and shear strength, were improved.
Composite wood products
Mostafa yahyavi; Abolghasem Khazaeyan
Abstract
Abstract In this study, wheat straw-polypropylene particleboard was produced using a mixture of wheat straw and polypropylene with urea formaldehyde resin and its properties were investigated. The ratio of polypropylene to the wheat straw particles was selected as 10:90, 20:80 and 30:70 percent. Urea ...
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Abstract In this study, wheat straw-polypropylene particleboard was produced using a mixture of wheat straw and polypropylene with urea formaldehyde resin and its properties were investigated. The ratio of polypropylene to the wheat straw particles was selected as 10:90, 20:80 and 30:70 percent. Urea formaldehyde was used at three levels of 4, 6 and 8 percent based on oven dried weight of wheat straw particle. Mechanical and physical properties (modulus of rupture, modulus of elasticity, internal bonding, water absorption and thickness swelling after 2 and 24h soaking in water) of the produced boards were measured. The results showed that increasing polypropylene and urea formaldehyde resin resulted in increasing the bending strength, modulus of rupture and modulus of elasticity of the boards. The results also indicated that water absorption and thickness swelling after 2 and 24h soaking in water decreased with increased polypropylene and urea formaldehyde resin percent. The UF resin content can be reduced in the particleboard as a function of increasing the PP powder.
Seaid Masoumeh Hafezi; Ali akbar ٍEnayati; Kazem Doosthosseiny; Asghar Taremian; Ahmad Mirshokraee
Abstract
This research was conducted to investigate the effect of silane coupling agent usage to improve the bond formation of urea formaldehyde resin in wheat straw particleboard production. Three levels (0.5% and 10%; based on the dry weight of the resin) of silane coupling agent and 10% urea formaldehyde resin ...
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This research was conducted to investigate the effect of silane coupling agent usage to improve the bond formation of urea formaldehyde resin in wheat straw particleboard production. Three levels (0.5% and 10%; based on the dry weight of the resin) of silane coupling agent and 10% urea formaldehyde resin were used to produce one layer particle boards with 16mm nominal thickness. Physical and mechanical properties including MOR, MOE, IB and thickness swelling (after 2 and 24 hours immersion in water) were measured. The results of this study showed that adding silane coupling agent to the resin in wheat straw particleboard production, increased MOR, MOE and IB and dimensions stability improved. Optimum dosage for silane coupling agent to improve modulus of elasticity, internal bonding and thickness swelling was 10% and the for modulus of rupture, it was determined as 5%.
Composite wood products
Yasamin Khosrevani; Ali akbar Enayati; Alinaghi Karimi; Behbood Mohebi
Abstract
The effects of different levels of wood particles acetylation and resin content on the physical and mechanical properties of particleboard were investigated. Boards were made within 6 treatments at three different levels of acetyl content (WPGs of 0%, 5.11% and 10.76 %) and two levels of resin content ...
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The effects of different levels of wood particles acetylation and resin content on the physical and mechanical properties of particleboard were investigated. Boards were made within 6 treatments at three different levels of acetyl content (WPGs of 0%, 5.11% and 10.76 %) and two levels of resin content (8 and 10 %).The results indicated that by increasing the level of particles acetylation, the density of boards was reduced whereas resin content increased this property. Equilibrium moisture content, water absorption and thickness swelling of the boards were reduced by 15.3%, 26.6% and 14.9%, respectively under optimum conditions as compared with control samples at higher acetylation levels and resin contents.MOR, MOE and IB decreased by increasing acetylation level but increasing resin content from 8 to 10 %, improved mechanical properties except for MOR which was not significantly affected by resin content. The result of this research have indicated that using 5.11% acetylation level and 10% resin content, it is possible to produce particleboard having enhanced physical properties with negligible loss of mechanical properties.
