Mehrab Madhoushi; Baratali Keshtegar
Abstract
In this study, the effect of epoxy resin modified by carbon nanofibers (CNFs) was investigated at three levels of zero, 0.4 and 1.5% on the strength properties of common corner joints in the furniture industry. Carbon nanofibers were dispersed in the adhesive polymer matrix by ultrasonic device and test ...
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In this study, the effect of epoxy resin modified by carbon nanofibers (CNFs) was investigated at three levels of zero, 0.4 and 1.5% on the strength properties of common corner joints in the furniture industry. Carbon nanofibers were dispersed in the adhesive polymer matrix by ultrasonic device and test specimens of joints were prepared using cut MDF pieces with desired dimensions and wooden dowel with diameters of 8 and 10 mm and penetration depth in two levels (D2 and D3) and using reinforced epoxy by CNFs. A total of 12 treatments with three replications were evaluated separately for each of the compressive and tensile tests and the flexural moment capacity of the joints specimens was evaluated at a speed of 3 mm/min. The results showed that by increasing the percentage of CNFs, diameter and penetration depth of dowel wood in the compression test, the flexural moment capacity 1.2,, 1.2 and 1.2 times, and in the tensile test 1.3, 1.1 and 1.2 times, respectively, increased compared to the control samples. In general, according to the research variables, it can be said that carbon nanofiber was able to improve the strength properties of epoxy resin and thus the joints. The level of 0.4% CNFS, diameter 10 mm and penetration depth of D2 dowel wood had the best effect on the strength of joints in two types of loading
Composite wood products
Mohammad Ghofrani; ali mohamadi
Abstract
This study investigated the comparative tension and compression strength of detachable edge joints in MDF and particle boards. Five pieces of each samples were provides in L shape with the size of 20*20 cm according to D 1761 ASTM. Fittings were applied in three types: cross, hexagonal shape and plastic ...
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This study investigated the comparative tension and compression strength of detachable edge joints in MDF and particle boards. Five pieces of each samples were provides in L shape with the size of 20*20 cm according to D 1761 ASTM. Fittings were applied in three types: cross, hexagonal shape and plastic fitting with 2 types of counter sink and butt screw were used. The results showed that the highest amount of tension strength was in cross shape metal joints and highest compression strength in hexagonal joints. Also the lowest strength of both tension and compression was observed in plastic joints. According to results, the joints with counter sink screws had higher strength than butt screw, and the failure place in this samples was like crevice in the bottom of boards. The data showed that the tension strength of all three fittings were higher than compression strength. The highest bearing of tension stress was in MDF with glue and dowel, counter sink screw and cross shaped fitting and the lowest was in particle boards without dowel, butt screw and plastic strips. The highest bearing of compression stress was in MDF with glue and dowel joint, hexagonal metal strip and counter sink screw, the lowest was seen in particle board without dowel, butt screw, and plastic strip.
Composite wood products
Morteza Nazeryan; Amin Dalirzadeh; Saeid reza Farokhpayam
Abstract
The effect of old corrugated container (OCC) powder as Urea Formaldehyde resin (UF) filler on the properties of medium density fiberboard (MDF) prepared from bagasse fibers and waste MDF was investigated. The variables in this research were the ratio of UF resin powder to OCC (at five levels; 100:0, ...
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The effect of old corrugated container (OCC) powder as Urea Formaldehyde resin (UF) filler on the properties of medium density fiberboard (MDF) prepared from bagasse fibers and waste MDF was investigated. The variables in this research were the ratio of UF resin powder to OCC (at five levels; 100:0, 5/5:1/98, 97:3, 5/5:4/95, and 94:6) and the ratio of bagasse fibers to waste MDF at five level; 100:0, 98:2, 96:4, 94:6 and 92:8).The constant variable in all treatments were 6 mm/min. press closing time and 150°Cpress temperature. Thickness swelling (TS), water absorption (WA) after 24h, modulus of elasticity (MOR), modulus of rupture (MOE) and internal bonding (IB)) of panels were measured according to EN standard and statistical analysis was performed using SPSS software. The results showed that OCC powder and MDF waste had significant effect on the bending strength and modulus of elasticity. An increase in OCC improved the internal bonding (IB) while IB was reduced by increasing of MDF waste. Minimum water absorption was found in panels with the maximum waste MDF. This means that the panels with 8 percent waste MDF had the least water absorption. Moreover, the panels with highest content of waste MDF had the least thickness swelling. No significant difference was found between the effects of various OCC powder content on the physical.
amir lashgari; Payam Khodayari; Seid Ali Mohammadi
Abstract
In this research the effect of nail′s length on three different values (32,42,48 mm)the nail number (2 and 3)and the kind of of particleboard and MDF on tensile strength and bending moment has been analyzed ,The member dimension of of 10*15*1.6 cm.have been elected for making of L –type ...
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In this research the effect of nail′s length on three different values (32,42,48 mm)the nail number (2 and 3)and the kind of of particleboard and MDF on tensile strength and bending moment has been analyzed ,The member dimension of of 10*15*1.6 cm.have been elected for making of L –type joint. The junction have not used out of any adhesive as an adjuvant. From combination of this variable factors and examination of any strength some 24 samples have created,that due to the 4 iterations,96 specimens of L shaped joints have been coustructed totally.the bending and tensile strength of produced junction has been measured by mechanical test machine.based on captured results the interaction of constituents of,nail penetration length,nails number and members nature on joint strenght weren′t significant in front of tensile and bending.this research indicated that the junctions with the penetration length of 48 mm,the most amount of nail(three nails)on MDF member elements,have the greatest strength against bending strength,and the link with penetration length of 42mm alone with the most amount of nail(3 nails)on MDF have the greatest strength against tensile,as copared with each other.
amir lashgari; Mohssen Ahmadi
Abstract
Aim of this study were to examine the effects of pin diameter (6, 8 and 10 millimeter), the pins interval ( 30,50 and 70 millimeter), wooden pin penetration depth (2d,3d and 4d D=Diameter of pin) and the shape of H joint on bending strength of the joint. In order to make the H joints, the dimension of ...
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Aim of this study were to examine the effects of pin diameter (6, 8 and 10 millimeter), the pins interval ( 30,50 and 70 millimeter), wooden pin penetration depth (2d,3d and 4d D=Diameter of pin) and the shape of H joint on bending strength of the joint. In order to make the H joints, the dimension of the middle member was selected as 200x125x16 millimeter and the dimension of the side members were selected as 250x125x16 millimeter. MDF was used to make the joints. The wooden pin used in the present research was made from hornbeam (Carpinus betulus) which is common pin in the market. PVA glue was used to make pin joints. Twenty seven treatments were obtained out of various combinations of the variables and considering four replication for each treatment, 108 H-shaped samples were prepared. The bending strength of the joints was measured. The results from mechanical test indicated that for each pin penetration depths in H joint, increasing the distance between pins, the bending strength decreased. Maximum bending strength was related to the pins having diameter of 10 millimeter. In 4d penetration depth, for each three diameters of 6, 8 and 10 millimeter, the maximum bending strength was reached on 30 millimeter intervals. The minimum bending strength for the pin having 6 millimeter diameter was obtained in the interval of 10 millimeter. The same results were obtained for the 2d and 3d penetration depths.
Composite wood products
Sayed mohammad javad Mosavi hosseini; Mohammad mehdi Faezipoor; Hossein Usefi
Abstract
The effect of using nanoclay on MDF properties was investigated. Sodium montmorolonit (NA+MMT) was used in three levels of 0, 3 and 6 percent based on dry weight of two resins of urea formaldehyde (UF) and Methylene diphenyl diisocyanate (MDI). Modulus of rupture (MOR), modulus of elasticity (MOE), internal ...
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The effect of using nanoclay on MDF properties was investigated. Sodium montmorolonit (NA+MMT) was used in three levels of 0, 3 and 6 percent based on dry weight of two resins of urea formaldehyde (UF) and Methylene diphenyl diisocyanate (MDI). Modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), thickness swelling (TS) and water absorption (WA) of MDF were measured based on EN standard. Results demonstrated that with the increase of nanoclay in both UF and MDI resins MOR and MOE of MDF increased significantly in such a way that with the use of UF containing 6% nanoclay MOR increased by 33%. Although, IB was significantly affected by UF containing nanoclay, MDI containig nanoclay caused reduction in IB. WA and TS of MDF made from MDI did not show significant variation by increase of nanoclay but those made from UF resin positively affected by adding nanoclay in such a way that MDF made from 3% nanoclay showed 41% loss in TS compared to those made from pure UF.
Composite wood products
Majid Chahar mahal; Saeid Kazemi najafi; Mehdi Tajvidi; Reza Hajihassani
Abstract
Wood -Plastic panels were made from high density polyethylene (as resin) and MDF waste and particleboard waste (as natural fiber) at 60, 70 and 80% by weight fiber loading. Density and dimensions of the panels were 1g/cm3and 35*35*1 cm, respectively. Physical properties of the panels including equilibrium ...
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Wood -Plastic panels were made from high density polyethylene (as resin) and MDF waste and particleboard waste (as natural fiber) at 60, 70 and 80% by weight fiber loading. Density and dimensions of the panels were 1g/cm3and 35*35*1 cm, respectively. Physical properties of the panels including equilibrium moisture content, long term water uptake and thickness swelling behavior were studied.Results indicated that equilibrium moisture content, maximum water uptake and thickness swelling of wood plastic samples increased with the increase in fiber content from 60% to 80%. Moreover, samples with higher fiber content faster reach to saturation point.
Composite wood products
Majid Chaharmahali; Saeid Kazeminajafi; Mehdi Tajvidi; Mohammad ali Podineh poor
Abstract
The possibility of producing wood-plastic panels using melt blend method was studied in this research and mechanical properties of the panels including flexural modulus, flexural strength, screw and nail withdrawal resistance, and impact strength were studied.Wood -Plastic panels were made from high ...
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The possibility of producing wood-plastic panels using melt blend method was studied in this research and mechanical properties of the panels including flexural modulus, flexural strength, screw and nail withdrawal resistance, and impact strength were studied.Wood -Plastic panels were made from high density polyethylene (as resin) and MDF waste and particleboard waste (as natural fiber) at 60, 70 and 80% by weight fiber loading. Density and dimensions of the panels were 1g/cm3and 35*35*1 cm, respectively. Results indicated that the mechanical properties of the composites are strongly affected by the proportion of the wood flour and polymer in the material. Maximum values of flexural modulus of wood plastic panels were found at 70% fiber content in both methods. Flexural strength, screw and nail withdrawal resistance and impact strength of wood plastic composites reduced with the increase in fiber content from 60% to 80%.
Composite wood products
Shamohammad Amiri; Ahmad Jahan latibari
Abstract
The property of MDF obtained the mixture of Haloxylon persicum wood (Saxaul) with Carpinus betulus (Hornbeam) at 100:0, 75:25, 50:50, 0:100 ratios is investigated in this study. The results of this study showed that there is significant statistical differences (1%) among combinations of woods for MOR, ...
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The property of MDF obtained the mixture of Haloxylon persicum wood (Saxaul) with Carpinus betulus (Hornbeam) at 100:0, 75:25, 50:50, 0:100 ratios is investigated in this study. The results of this study showed that there is significant statistical differences (1%) among combinations of woods for MOR, MOE, IB, thickness swelling after 2 & 24 hours and water absorption after 2 & 24 hours. The bending strength (MOR) of MDF produced of Hornbeam wood fibers was highest and Saxaul wood fibers were lowest. Boards produced from 50% Hornbeam and 50% Saxaul, showed the important of bending strength 57%. The average modulus of elasticity (MOE) of MDF showed significant statistical differences (1%). MDF produced from Hornbeam wood fibers had showed highest MOE and Saxaul wood fibers showed lowest MOB. The result of internal bonding (IB) showed that MDF produced from Saxaul wood fibers possessed lowest IB and Hornbeam wood fibers had highest IB. In other two combinations of Hornbeam and Saxaul wood fibers, there are no significant statistical differences (1%) with MDF produced from only of Hornbeam wood fibers.
Composite wood products
Majid Chaharmahali; Saeid Kazemi najafi; Mehdi Tajvidi
Abstract
The possibility of producing wood-plastic panels using two methods including melt blend and dry blend was studied in this research. Methods were compared with each other in order to select the best. Wood-Plastic panels were made from high density polyethylene (as resin) and particle board waste (as natural ...
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The possibility of producing wood-plastic panels using two methods including melt blend and dry blend was studied in this research. Methods were compared with each other in order to select the best. Wood-Plastic panels were made from high density polyethylene (as resin) and particle board waste (as natural fiber) at 60, 70 and 80% by weight fiber loading. Density and dimensions of the panels were lg/cm3 and 35*35*1 cm, respectively. Mechanical properties of the panels including flexural modulus, flexural strength, screw and nail withdrawal resistance, and impact strength were under investigation. Maximum values of flexural modulus of wood plastic panels were found at 70% fiber content in both methods. Flexural strength, screw and nail withdrawal resistance and impact strength of wood plastic composites reduced with the increase in fiber content from this is not a reduction 60% to 80% is increase. Mechanical properties of samples made with dry blend method were generally higher than those of samples made with melt blend method for an corresponding formulations.
Composite wood products
masoudreza habibi; Abdolrahman Hosseinzadeh; Hossein Hosseinkhani; Saeed Mahdavi
Abstract
In this study the effect of two variables, (resin content and press time) on properties of MDF was investigated. Levels of each variable was as follow: Resin content (8, 9.5, 11 percent) Press time (4, 5, 6 minutes). The statistical analysis proved that the effect of press time on MOE and MOR was significant. ...
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In this study the effect of two variables, (resin content and press time) on properties of MDF was investigated. Levels of each variable was as follow: Resin content (8, 9.5, 11 percent) Press time (4, 5, 6 minutes). The statistical analysis proved that the effect of press time on MOE and MOR was significant. MOE and MOR were the highest at press time of 6 minutes. According to Duncan's test, there aren’t any significant differences between MOE at press time of 5 and 6 minutes. Also the effect of resin content on MOE had significant differences. MOE was the highest at resin content of 11%. There aren’t any significant differences between MOE on resin content at 9.5% and 11% levels. The results showed that effects of press time and resin content had significant differences on IB. IB was the highest at press time of 6 minutes and resin content of 11%. There aren’t any significant differences between IB on resin content at 9.5% and 11%. The effects of press time and resin content had significant differences on thickness swelling after 2 hours. Thickness swelling was the lowest at press time of 6 minutes and resin content of 11%. According to the results of this study optimum combination for MDF production from baggasse includes resin content and press time of 9.5% and 5 minutes respectively.
