Composite wood products
Abbas Tamjidi; Mohamad Mehdi Faezipour; Habibollah Khademi Eslam; Ghanbar Ebrahimi; Kazem DoosthoseinI
Abstract
DOR:98.1000/1735-0913.1398.34.140.66.1.9.1586 In this study, the possibility of three-layered oriented strand board production from hornbeam (Carpinus betulus L.) wood was evaluated. Two levels of press time (6 and 8 minutes) and three levels of press temperature (180˚C, 200˚C and 220˚C) were applied ...
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DOR:98.1000/1735-0913.1398.34.140.66.1.9.1586 In this study, the possibility of three-layered oriented strand board production from hornbeam (Carpinus betulus L.) wood was evaluated. Two levels of press time (6 and 8 minutes) and three levels of press temperature (180˚C, 200˚C and 220˚C) were applied and 12 mm thick laboratory boards were made from hornbeam wood. The strands on the surface layers were aligned in the long direction of the board and the middle layer strands are cross aligned to the surface layers. In all treatments, board targeted density of 0/7 g/cm3 and mat moisture content of 7% and phenol-formaldehyde resin (PF) content of 7% based on the oven dry weight of the strands were kept constant. The mechanical and physical properties of the boards were measured as defined in relevant European standards test methods EN 300. The internal bound (IB) and thickness swelling (TS24) of boards were significantly improved as the press time increased from 6 to 8 minutes. The modulus of rupture (MOR) and internal bound (IB) and thickness swelling (TS24) were significantly improved as the press temperature increased from 180˚C to 220˚C. Overall results showed that the highest MOR and IB and the lowest TS24 were achieved at 8 minutes press time and 220˚C press temperature and all boards made from this mentioned conditions exceed the EN 300 standards for MOR, MOE, IB and TS24.
Composite wood products
Aliakbar Aenayati; Halimeh Pangh; Mahammad Layeghi; Kazem Doosthosseini
Abstract
This study was conducted to investigate the effect of Cu nano particles addition on the density profile and mechanical properties of medium density fiberboard. One layer fiberboard (MDF) with the density of 0.58g/cm3and thickness of 17 mm were produced using Cu nano particles in three levels (5, 10 and ...
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This study was conducted to investigate the effect of Cu nano particles addition on the density profile and mechanical properties of medium density fiberboard. One layer fiberboard (MDF) with the density of 0.58g/cm3and thickness of 17 mm were produced using Cu nano particles in three levels (5, 10 and 15wt%based on solid content of resin) and urea formaldehyde resin content in two levels (8 and 10wt%based on oven dry weight of fibers) as variable factors. The control panels were produced using 10% resin (based on oven dry weight of fibers) without Cu nano particles using the identical manufacturing parameters as other panels. Mechanical strength including internal bonding (lB), bending strength, modulus of elasticity and density profile using slicing method were determined. The results indicated that increasing the content of Cu nano-particles had no significant effect on the internal bonding as well as bending strength and modulus of elasticity of panels. Increasing the resin content from 8 to 10 percent improved modulus of elasticity (43.7%), bending strength (18.9%) and internal bonding (23%) of panels. In addition, the increasing Cu nano particles up to 5% caused relatively higher IB for panels produced using 8%resin compared to the control panels(containing10% resin) as well as the density profile was more uniform with the lowest differences between maximum and minimum density in the density profile.
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%.
