Reza Jazayeri; saeed kazemi najafi; Habibollah Younesi; Abolfazl Kargarfard
Abstract
In this study, the effect of graphite and two modified graphite materials in reducing formaldehyde emission of medium density fiberboard (MDF) was investigated. For this purpose, expanded graphite (EG) was syntesyzed from graphite (G) and modified expanded graphite (MnO2-EG) was produced through the ...
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In this study, the effect of graphite and two modified graphite materials in reducing formaldehyde emission of medium density fiberboard (MDF) was investigated. For this purpose, expanded graphite (EG) was syntesyzed from graphite (G) and modified expanded graphite (MnO2-EG) was produced through the intercalation process of expanded graphite with manganese dioxide. Thus, three graphite materials were prepared for resin treatment. Molecular tests including X-ray diffraction (XRD) and X-ray diffraction spectroscopy (SEM-EDS) were performed to determine their molecular properties,. In addition, the differential scanning caliber test (DSC) test was performed to evaluate the thermal behavior of the resin under the influence of these graphite materials as additive. The additives were added to urea formaldehyde resin at three levels of consumption of 1, 2 and 3%, and then medium density fiberboard (MDF) with a density of 750 kg/m3 was made from glued fibers. After making the board, the formaldehyde emission test was performed by desiccator method. Overall, MnO2-EG showed better results than control and two other graphite treatments. The best performance was resulted by MnO2-EG at level 3% so that reduced formaldehyde emission by about 61%. It seams the formaldehyde molecules absorbed into the expanded graphite layers were exposed to oxidation by manganese dioxide molecules. On the other hand, as the DSC test showed, the highest anthalopy reaction occurred in resin treated by MnO2-EG, indicating an increase in the reaction of formaldehyde molecules in the resin structure.
Composite wood products
Farhad Ghotbaldin; Habib alah Khademieslam; Amir Nourbakhsh; Mohammad Talaeipoor
Abstract
An experiment was conducted to study polymerization conditions and important production factors, the amount of resin and press temperature, on physical and mechanical properties of produced boards by urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were compared. Purify UF resin (control treatment) ...
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An experiment was conducted to study polymerization conditions and important production factors, the amount of resin and press temperature, on physical and mechanical properties of produced boards by urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were compared. Purify UF resin (control treatment) and its mixture with MUF at 25, 50 and 75% proportions in 170 and 180˚C temperature were used to make homogen particle boards. The proportion of resin to particles was 10 percent by dry weight. Other production factors were assumed as fix factors. Eight experimental groups (treatment) with three replications per each were studied. Produced particles were derived from species Alnus subcordata. Physical and mechanical properties measurement prepared samples were based on European EN standard. Examined Physical characteristics were water absorption and thickness swelling and mechanical characteristics were modulus of rupture, modulus of elasticity and so internal bond. The data were analyzed in completely randomized design with factorial arrangement (4*2). Statistical significances among treatment means were determined by multiple range test of Duncan. The results of this study showed that physical and mechanical properties of boards were improved by increasing the level of MUF resin and temperature. Eventually, with consideration all results and so quality and economical aspects of produced particleboard by MUF resin and its comparison with control group we have concluded that 50 percent of MUF resin and 180 degree centigrade of press temperature are optimal levels.
Composite wood products
Abdolrahman Hosseinzadeh; Amir Nourbakhsh; Abolfazl Kargarfard; Fardad Golbabaei; Morteza Nazeryan
Abstract
Decreasing availability of raw material for Iranian wood industries and the need to conserve our limited natural forests initiated research concerning the utilization of fast-growing species in particleboard production. The objective of this study was to investigate the possibility of particleboard production ...
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Decreasing availability of raw material for Iranian wood industries and the need to conserve our limited natural forests initiated research concerning the utilization of fast-growing species in particleboard production. The objective of this study was to investigate the possibility of particleboard production from wood of two- year- old coppices of 17 experimental populus clones grown under intensive culture in the "Alborz Research Center" near Tehran. The furnish contained mixture of stem and branch wood with bark used to make 51 sample boards (3 board from each clone). Modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength (IB), thickness swelling and water absorption of the specimens were tested. The results indicate that sample boards made from Populus euramericana costanzo and populus euramericana 561.41 had significantly the highest MOR and MOE. But there was no significant differences in the internal bonding strength between different clones, while, those sample boards made from populus nigra betulifolia and Populus nigra nivea showed significantly the lowest percentages of thickness swelling. The average physical and mechanical properties of the particleboard samples produced from two- year- old coppices of poplar clones compared favourably to boards made from natural grown beech wood. Therefore, using UF resin, particleboard with acceptable quality particleboards can be produced from two- year- old poplar clones.
