Mohammad Reza topa esfandiyari; Mohammad Talaei poor; Habibollah Khademi Eslam; Seeyed Ahmad Mirshokraie; Behzad Bazyar
Abstract
This study uses the Lignin-Glyoxal adhesive to replace chemical resins with environmental compounds producing plywood. producing plywood, pure Lignin (L.100%), lignin- glyoxal 15% (L.85-G.15), lignin-glyoxal 30% (L.70-G.30) and Urea-formaldehyde (control) were used as adhesive at 160 gr/m2 level. Accompanied ...
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This study uses the Lignin-Glyoxal adhesive to replace chemical resins with environmental compounds producing plywood. producing plywood, pure Lignin (L.100%), lignin- glyoxal 15% (L.85-G.15), lignin-glyoxal 30% (L.70-G.30) and Urea-formaldehyde (control) were used as adhesive at 160 gr/m2 level. Accompanied with ammonium chloride (1%) as the hardener and wheat flour (30%) as the filler based on the dry weight of the adhesive characteristics of adhesives included solid material percentage, viscosity, specific weight and PH were measured. After producing the laboratory boards, the physical and mechanical properties of samples, such as thickness swelling after 2 and 24 hours of being soaked in water, shear strength, modulus of rupture, and modulus of elasticity were measured. In addition, the groups and bonds in the pure lignin and lignin-gloxal adhesives were identified by Fourier Transform Infrared (FTIR) spectroscopy. The results indicated that the independent effect of adhesive type on the thickness swelling of plywood after 2 and 24 hours was significant. Although the results suggest that modifying the lignin would improve the plywood in all cases, the control boards had better featurers than those made with the Lignin-Glyoxal adhesive.
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.
Amir Eshraghi; Habib alah Khademeslami; Amir Nourbakhsh; Behzad Bazyar; Mohammad Talaeipoor
Abstract
In this study, aspen chips with OCC (Old Corrugated Container) were used in particleboard production and samples were prepared at two different levels of resin contents (%9 and %10) and three levels of combination:
1- %25 OCC +%75 aspen, 2- %50 OCC + %50 aspen, ...
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In this study, aspen chips with OCC (Old Corrugated Container) were used in particleboard production and samples were prepared at two different levels of resin contents (%9 and %10) and three levels of combination:
1- %25 OCC +%75 aspen, 2- %50 OCC + %50 aspen, 3- %75 OCC +%25 aspen. Indeed in this study these two mentioned factors are variable and other factors such as press temperature: 165 ºC, press time: 5 minute, mat moisture %12, board density 0.75 g/cm3 and press pressure 30 kg/cm2 were constant. After the boards were manufactured according to DIN-68763 standard, were undergone different tests such as: bending strength, modulus of elasticity, internal bonding strength and thickness swelling after 2 & 24 hours immersion in water. The results indicate that second ratio(%50 OCC and %50 aspen chips) is proper for bending applications and the first ratio(%25 OCC and %75 aspen chips) is proper for tensile and thickness swelling applications. Therefore, applying the OCC more than %50 in manufacturing combination; result in decreasing the physical and mechanical properties. Moreover the results show that when the resin content increases, the board features improve.
mohammad ghofrani; Habib Nori
Abstract
In the present study the strength of different kinds of wooden dowels, screws, and ready-to-assemble joints (RTA joints) used in medium density fiberboards (MDF) were assessed and compared for their lateral shear strength. The T-form specimens (20 cm × 8 cm) were comprised of two MDF parts in compliance ...
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In the present study the strength of different kinds of wooden dowels, screws, and ready-to-assemble joints (RTA joints) used in medium density fiberboards (MDF) were assessed and compared for their lateral shear strength. The T-form specimens (20 cm × 8 cm) were comprised of two MDF parts in compliance with ASTM D1761 standard. Five specimens for each treatment were made and a total of 20 treatments were designed; treatments in this study are as follows:Rough as well as smooth dowel joints with 8 and 10 mm diameter, using urea-formaldehyde and poly-vinyl acetate adhesives; Screw joints, sizes 5 and 6, with or without urea-formaldehyde as well as poly-vinyl acetate adhesives; And, different kinds of RTA joints.Results indicate that different kinds of screw joints show the most powerful joints in comparison with other kinds of joints; but there was no significant difference between different kinds of screw joints. Therefore, having economical points of view in mind, screw joints size 5 is recommended to be used without adhesive. The effect of dowel surface as independent variable was statistically significant, while the interaction effect of dowel diameter, adhesive, and quality of dowel surface on lateral shear strength, as well as the independent and interaction effects of two factors of combined wooden dowel along with joint, and adhesive on the strength of RTA joint (that has nuts) were statistically significant.
Composite wood products
Amir Nourbakhsh; Abolfazl Kargarfard
Abstract
In this study the effect of resin content and press time of particleboard from Date palm residues, Eucalyptus camaldulensis, Tamarix residues and prosopis (Mesquite) producted were investigated in southern of Iran.Variable factors as resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) ...
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In this study the effect of resin content and press time of particleboard from Date palm residues, Eucalyptus camaldulensis, Tamarix residues and prosopis (Mesquite) producted were investigated in southern of Iran.Variable factors as resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) and total of 27 boards were fabricated. Other factors such as type of resin (UF), hardener content (2 percent) type of hardener (NH4Cl) press closing time (4.5 mm/sec.), board density (0.7 gr/cm3) press pressure (30 kg/cm2) and press temperature (160 °C)were held constant.All boards were tested according to DIN-68763 standard. The factorial experimental design at completely random test was used. The results of this study could be summarized as follows:Increasing the resin content from 9 to 11 percent, MOE and IE and decreased thickness swelling after two and 24 hours immersion in water. The results revealed that the polymerization of resin and wood is better at 11 percentresincontentand6 minutes of press time.
Composite wood products
asghar tarmian; Kazem Doosthosseini; Seeyed Ahmad Mirshokraie; Mohammadmehdi Faezi poor
Abstract
Beneficial utilization of large quantity of paper sludge from Mazandaran Wood & Paper Industry in particleboard manufacturing has been studied. Single-layer and three-layer particleboard (paper sludge as a surface layer) were produced. Urea-formaldehyde resin at two levels of 10 and 12 percent and ...
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Beneficial utilization of large quantity of paper sludge from Mazandaran Wood & Paper Industry in particleboard manufacturing has been studied. Single-layer and three-layer particleboard (paper sludge as a surface layer) were produced. Urea-formaldehyde resin at two levels of 10 and 12 percent and paper sludge content at 4 levels, 0, 15, 30 and 45 percent were studied. Other factors such as press temperature (160oC), press time (6minutes), mat moisture (12%), board density (0.75g/cm3) and etc were constant factors. Mechanical and physical properties including bending strength, shear strength, thickness swelling and water absorption after 2 and 24 hours immersion were evaluated. The results indicated that application of paper sludge reduced mechanical properties and improved thickness swelling .The particleboard produced with 15%paper sludge had the least water absorption, but by using more paper sludge, water absorption increased. Single-layer particleboard had higher bending strength. However, there was no significant different in shear strength between single and three layer particleboard. Three-layer particleboard showed lower thickness swelling.
