Composite wood products
Behzad Hosseini; mohammad ghofrani; Hamid Reza Taghiyari; Saman Ghahri
Abstract
In this research, Effect of soy flour addition into urea-formaldehyde resin on physical, mechanical properties and formaldehyde emission of plywood was investigated. Soy flour was mixed with urea-formaldehyde adhesive in three levels 5, 10 and 15% (based on dry weight of urea-formaldehyde adhesive) and ...
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In this research, Effect of soy flour addition into urea-formaldehyde resin on physical, mechanical properties and formaldehyde emission of plywood was investigated. Soy flour was mixed with urea-formaldehyde adhesive in three levels 5, 10 and 15% (based on dry weight of urea-formaldehyde adhesive) and three-layer plywood was manufacture from the resultant adhesive and poplar veneer. Properties of manufactured plywood including formaldehyde emission according to EN-717-3 standard, shear strength according to EN-314 standard and water absorption and thickness swelling according to EN-317 standard were investigated. The results indicated that addition of soy flour up to 15% decreased formaldehyde emission up to 29.34% and increased shear strength of panels. Moreover, delamination test (According to ANSI/HPV-HPV1 Standard) presented acceptable results. The results obtained from water absorption and thickness swelling after 2h and 24h showed that addition of soy flour increased the amount of water absorption and thickness swelling. thickness swelling after 2h and 24h showed that addition of soy flour increased the amount of water absorption and thickness swelling.
Mosayeb Dalvand; Ghanbar Ebrahimi; Mehdi Tajvidi; Mohammad Layeghi
Abstract
The bending moment resistance under diagonal tensile load of doweled joint in plywood members was investigated. Joint members were cut from 11-ply hardwood plywood (Beech, Hornbeam and Alder) at the nominal thickness of19 mm. Dowels were made of Beech and Hornbeam woods. Dowel diameters (6, 8 and10 mm) ...
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The bending moment resistance under diagonal tensile load of doweled joint in plywood members was investigated. Joint members were cut from 11-ply hardwood plywood (Beech, Hornbeam and Alder) at the nominal thickness of19 mm. Dowels were made of Beech and Hornbeam woods. Dowel diameters (6, 8 and10 mm) and depths of penetration (9, 13 and17 mm) in the joint members were selected as variables. The effect of dowel variables on the bending moment of the corner joints was evaluated. Results showed that the dowel diameter, penetration depth and species exerted a significant effect on the bending moment resistance under diagonal tensile load. Bending moment resistance under diagonal tensile load was increased as the diameter of the dowel increased from 6 to8 mmand as the penetration depth of dowel increase from 9 to13 mm. However, increasing the diameter from 8 to10 mmor the penetration depth from 13 to17 mmhad no significant effect on bending moment resistance under diagonal tensile load. Results also indicated that bending moment resistance of joints made with beech wood dowels provided higher resistance than hornbeam dowels.
Sadegh Maleki; Mohammad Mehdei Faezipour; Ghanbar Ebrahimi; mohammad Layeghi
Abstract
The goal of this study was to investigate bending moment resistance of L-shaped screwed corner joints constructed of Plywood members. The thickness of plywood members was nominal 19mm that were compared with medium density fiberboard (MDF) and particleboard with 18mm thicknesses. Effects of thread screws ...
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The goal of this study was to investigate bending moment resistance of L-shaped screwed corner joints constructed of Plywood members. The thickness of plywood members was nominal 19mm that were compared with medium density fiberboard (MDF) and particleboard with 18mm thicknesses. Effects of thread screws (coarse and fine), screw diameter (3.5, 4 and 5 mm), and penetration depth (9, 15 and 28) on bending moment capacity of joints under diagonal tension were investigated. Test results indicated that a screw corner joint becomes stronger as either screw diameter or screw length is increased. Screw length was found to have a greater effect on moment capacity than the diameter. The highest bending moment resistance was observed for joints made with coarse screw which were 5 mm in diameter and 28 mm depth of penetration. The lowest bending moment resistance was observed in joints having fine screw, with 3.5 mm diameter and 9 mm penetrations. Results also showed that bending moment resistance with coarse thread drywall screws was higher than those of the fine thread drywall screws. Bending moment resistance of joints made of plywood was higher than those of joints made of medium density fiberboard (MDF) and particleboard.
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.
Composite wood products
Ali akbar Enayati; Davood Rasooli; Hossein Usefi
Abstract
In this study, plywood manufacture with use of polypropylene as a binder has been studied. The variables were polypropylene in three levels of 80, 120 and 160 g/m2 and maleic anhydride polypropylene coupling agent in two levels of 0 and 4 g/m2 . ureformaldehyde and wheat flour were ...
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In this study, plywood manufacture with use of polypropylene as a binder has been studied. The variables were polypropylene in three levels of 80, 120 and 160 g/m2 and maleic anhydride polypropylene coupling agent in two levels of 0 and 4 g/m2 . ureformaldehyde and wheat flour were used for control samples(120 and 40 g/m2 respectively). Physical and mechanical properties including MOR and MOE (parallel and perpendicular to grain of face layers), water absorption and thickness swelling after 2 and 24 hours of immersion in water were tested. The results showed that maleic anhydride polypropylene coupling agent has significant effect on MOR parallel to grain of face layers. With increase of maleic anhydride polypropylene coupling agent, MOR increased. Polypropylene has positive effect on thickness. With increase of maleic anhydride polypropylene coupling agent, water absorption after 24 hours improved. Although the results revealed improvement in board properties resulted from more polypropylene use but in all properties (except thickness swelling after 24 hours), control samples had better quality than plywood made from polypropylene.
