Abolfazl Kargarfard; Reza Haji hassani
Abstract
The aim of this investigation was concentrated on the possibilty of untilizing corn cops residues in the production of particleboard. Two press temperatures of 170 and 180 oC, and four ratios of corn cop/poplar wood particles (100/0, 75/25, 50/50 and 25/75) in the corn layer of the boards and 100% poplar ...
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The aim of this investigation was concentrated on the possibilty of untilizing corn cops residues in the production of particleboard. Two press temperatures of 170 and 180 oC, and four ratios of corn cop/poplar wood particles (100/0, 75/25, 50/50 and 25/75) in the corn layer of the boards and 100% poplar wood particles in the surface layer were used. A combination of 16 treatments were reached and three laboratory boards for each treatment were made. Physical and mechanical properties of the boards were measured and statistically analyzed. The grouping of the averages were based on duncan multiple range test. The results indicated that the influence of the press temperature on both modulus of rupture and modulus of elasticity was statistically significante and boards produced applying 170 oC reached higher values. As the ratio of the corn cop particles in the particle mixture in core layer increased, both modulus of rupture and internal bonding deteriorated and the highest value were measured at 50/50 ratio of the particle in the core layer. The Boards which produced applying higher press temperature exhibited hgiher rate of thickness swelling . Lower ratios of the corn cop particle in the mixture of particles in the core layer improved the properties of the boards. So that the ratio of 50/50/ and 25/75 produced lower thickness swelling. The results of this research revealed that eventhough boards produced using corn cop particles did not produce comparable properties to the boards based on poplar particles, but it can be concluded that if 50/50 ratio of particles, press temperature of 170 oC is used for board making, the mechanical properties of the produced boards will meet the requirement of DIN specifications.
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
Abolfazl Kargarfard; Abdolrahman Hosseinzadeh; Amir Nourbakhsh; Ali Fatolahzadeh
Abstract
Particleboard industries are a dynamic industry, that has been established and grown rapidly in Iran. Demand for Particleboard has been increased rapidly due to increase population, thus the possibility of utilization residues from other wood using industries or other lignocellulosic raw materials should ...
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Particleboard industries are a dynamic industry, that has been established and grown rapidly in Iran. Demand for Particleboard has been increased rapidly due to increase population, thus the possibility of utilization residues from other wood using industries or other lignocellulosic raw materials should be investigated. The boards made for this study contained Haloxylon sp. and wheat straw at 0: 100, 75: 25, 50: 50 and 25: 75 ratios as raw material. Samples of all the boards made were tested by the methods described in DIN 68763 standard, to obtain mean values of bending strength, internal bond strength (IB) and thickness swelling.The results of this study showed that there are no significant statistical differences among each combination for MOR and MOE but with increasing the percentage of wheat straw the MOR of boards was found to increase. There were statistical differences among each combination of IB wheat straw had the lowest IB, where as the highest IB were observed on the boards with 100 percent Haloxylon sp.In addition, samples of each type of board were tested for thickness swelling (T.S) after immersion in water for 2 and 24 hours respectively, and the results indicate that there were statistical differences among each combinations and the lowest thickness swelling value was belong to the boards with 100 percent Haloxylon sp. which had the highest IB. It was also observed that the board made of Haloxylon sp. and wheat straw at with 25: 75 ratio had the highest T.S immersion in water after 2 and 24 hours.
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
Leila Fathi; Mohammad mehdi Faezipoor; Mohsen Bahmani
Abstract
In this investigation the effect of using of UF and MUF Resins on Physical and mechanical Properties of Particleboards Produced from Rice Straw and Aspen Particles has been studied. The aim of this study was to determine of physical and mechanical properties of rice straw– particleboard. ...
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In this investigation the effect of using of UF and MUF Resins on Physical and mechanical Properties of Particleboards Produced from Rice Straw and Aspen Particles has been studied. The aim of this study was to determine of physical and mechanical properties of rice straw– particleboard. Single-layer particleboard was produced. That was produced with 11% MUF and 11% UF. For using of UF and MUF 2% hardener was added to adhesives. The Press condition for MUF was: 1750C for 4 minutes and also for UF application was 1750C for 6 minutes. Another variable factor was the rice straw content in three levels (15%, 30% and 45%). Other factors such as board density (0/7gr/cm3), mat moisture (12%) were constant factors. The results indicate that increasing rice straw to wood particles cause some reduction in modulus of rupture , and internal bonding , and some increase in thickness swelling , and water absorption of manufactured boards. But comparing and grouping means by Duncan test showed that in the most case these effects were insignificant when rice straw add to wood particle up to 30%. Particleboard bonded with 11% MUF had the highest bending strength. Particleboards bonded with MUF had better bending strength, shear strength, thickness swelling and water absorption after 2, 24 hours immersion. Grouping the experimental data while using Duncan method was indicated of the fact that an optimum condition for manufacturing particleboard while using a mixture of rice straw and wood particles is to add 30% rice straw to the mixture , use 11% melamine urea formaldehyde resin and employ a pressing time of 4 minutes.
Composite wood products
Masoudreza Habibi
Abstract
The purpose of this study was to use of Hemp stalks in particleboard production. Mixtures of Hemp stalk and Eucalyptus wood at the ratios of 0:100, 50:50, 100:0 were used. Also two resin content of 8 and 10% (based on oven dry particle) and 2 press times of 3 and 4 minutes were employed for the production ...
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The purpose of this study was to use of Hemp stalks in particleboard production. Mixtures of Hemp stalk and Eucalyptus wood at the ratios of 0:100, 50:50, 100:0 were used. Also two resin content of 8 and 10% (based on oven dry particle) and 2 press times of 3 and 4 minutes were employed for the production of laboratory particleboard. Physical and mechanical properties including thickness swelling after 2 and 24 hours soaking in water, modulus of rapture, modulus of elasticity and internal bonding were measured data were statistically analyzed. It was observed that the increase in Hemp stalk particles in the mixture resulted in increasing of bending properties (bending strength and modulus of elasticity) and thickness swelling after 2 and 24 hours water soaking. Also the results showed that increase in Hemp stalk particles in the mixture resulted in reduction of internal bonding. As expected, physical and mechanical properties of particleboard improved with increasing resin content. Modulus of elasticity and thickness swelling after 24 hours water soaking were improved with increasing of press time. In general, comparing the produced board mechanical properties with standard of Iran requirements, the board produced using 100% and 50% Hemp stalk, 8% resin content and 3 minutes press time showed that optimal properties. Although the physical properties of the boards did not meet the standard values, the reason for this could not be due to the lack of use of paraffin.
Composite wood products
Abolfazl Kargarfard; Amir nourbakhsh; Fardad Golbabaei
Abstract
The aim of this study has been utilization of recycled polyethylene in modification of physical and mechanical properties of particleboard. Therefore, three levels of resin consumption content ( 10, 7 and 4% ) and three levels of recycled polyethylene consumption content 5, 10 and 15% in surface layer ...
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The aim of this study has been utilization of recycled polyethylene in modification of physical and mechanical properties of particleboard. Therefore, three levels of resin consumption content ( 10, 7 and 4% ) and three levels of recycled polyethylene consumption content 5, 10 and 15% in surface layer of mat, particleboards produced. Also in order to influence of these variables on physical and mechanical properties of produced boards, 3 particleboards with 10% resin content in surface layer and without polyethylene as control samples produced. The physical and mechanical properties of boards measured and analyzed. The results of this study indicated that with increasing of the recycled polyethylene consumption content, the MOR, MOE and thickness swelling of boards improved significantly and the produced boards with 15% recycled polyethylene in compare with control boards increased 59 and 53% respectively. Also the results revealed that the water absorption of boards decreased with increasing of increasing of recycled polyethylene consumption content, and the minimum of water absorption of boards observed in the produced boards with 15% recycled polyethylene. Based on the results of this research and with increasing of polymeric residues in the envirement , we conclude that the utilization of recycled polyethylene in particleboard production has different advantages.
Physics and anatomy
Vahid Safdari
Abstract
Understanding of many wood technological features depends on anatomical characteristics which, unfortunately, researchers in Iran have not focused on recently. There are many trees and shrubs in the desert areas of Dasht-e Kavir and Dasht-e Lut with unstudied woody anatomical features. We studied one ...
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Understanding of many wood technological features depends on anatomical characteristics which, unfortunately, researchers in Iran have not focused on recently. There are many trees and shrubs in the desert areas of Dasht-e Kavir and Dasht-e Lut with unstudied woody anatomical features. We studied one of these species, Calligonum comosum (Polygonaceae). Three mature shrubs were selected and small cubic samples of woody stem and root were taken. Micro-sections were obtained with micro-tome and after dying with Astra-blue and Safranin the sections were mounted in Canada balsam. The results showed that many differences between roots and stems exist, such as distinct growth rings in the stems and indistinct rings in the roots, the presence of gums in the stems and absence in the roots, and lower ray width of the stems compared to the roots, inherent characteristics that have been reported by many other researchers. The most important difference between Calligonum comosum’s roots and stems is parenchyma-like fibers in the thin-walled roots which cannot be distinguished from axial parenchyma. The ground tissue of woody roots is parenchymatous cells full of starches, which probably can be related to the drought situation of deserts. The bark of Calligonum comosum has priderm and sclereid cells which make the bark stiff and hard. Also the result of particleboard of fabricated of Calligonum comosum’s wood showed that boards has at least technical characteristics of European Standard EN 312 and hence the silviculture of this species for stooping of erosion of soil and is suitable species for desertification and its wood can be used for producing of wood based panel.
Composite wood products
Sajad Akbari; Morteza Nazeryan; Saeid reza Farokhpayam; Babak Nosrati sheshkal
Abstract
In this study the possibility of using canola stalks mixed with poplar wood in the manufacture of particleboard was investigated. Weight ratio of canola particle to poplar particles at five levels (98, 93/75, 87/50, 81/25, 77%), the weight ratio of the urea-formaldehyde/melamine formaldehyde resin as ...
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In this study the possibility of using canola stalks mixed with poplar wood in the manufacture of particleboard was investigated. Weight ratio of canola particle to poplar particles at five levels (98, 93/75, 87/50, 81/25, 77%), the weight ratio of the urea-formaldehyde/melamine formaldehyde resin as a adhesive at five levels (23, 18/75, 12/50, 6/25, 2%) and moisture content of matt at five levels (10, 12, 15, 18, 20%) were selected as production variables. Mechanical properties of boards consist of MOR, MOE and IB was tested. According to the results, with increasing the canola stalks/poplar particle ratio MOR and MOE of the boards decreased, but all of the values obtained from treatments were higher than standard. Interaction effect analysis of variables showed that the increasing the ratio of melamine formaldehyde/urea formaldehyde resin decreased the bending strength, while the increasing the moisture of mat increased MOR and MOE. IB values of all treatments are lower than the standard. According to the results of response surface methodology (RSM) and interaction effect between studied variables on the mechanical properties of the panels, the best situation for producing the panels was selected as: weight ratio of 84/32 for canola/poplar particle, ratio of 6/25 for UF/MF resin and moisture content of 12% for mattress.
Composite wood products
Mohsen Saffari; mohammad reza ranjbar; mohammad ali ghavidel; abdollah hosseinzadeh
Abstract
AbstractThe aim of present study was to determine the relationship between ultrasonic wave velocity and mechanical properties of particleboard panels. For this purpose, homogenous and layering particleboards were made by 0/7 g/cm3 density and 16 mm thickness. After conditioning and preparing samples, ...
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AbstractThe aim of present study was to determine the relationship between ultrasonic wave velocity and mechanical properties of particleboard panels. For this purpose, homogenous and layering particleboards were made by 0/7 g/cm3 density and 16 mm thickness. After conditioning and preparing samples, ultrasonic wave velocity was measured in different directions of samples. Then modulus of elasticity, modulus of rupture and internal bonding of samples were measured by mechanical test machine. Result indicated that ultrasonic wave velocity of particleboard samples was higher in longitudinal direction than other directions. Relationship between ultrasonic wave velocity and mechanical properties was determined by linear correlation regression. Correlations between ultrasonic wave velocity and modulus of elasticity, modulus of rupture and internal bonding were significant in thickness direction of particleboard samples. Correlations between ultrasonic wave velocity and modulus of elasticity, modulus of rupture and internal bonding were significant in thickness direction of particleboard samples. Correlations between ultrasonic wave velocity and modulus of elasticity, modulus of rupture and internal bonding were significant in thickness direction of particleboard samples.
Management and Economics wood
Aliakbar Aenayati; Hamid Hatefnia
Abstract
Microbiological degradation of wood and wood products is one of the most important of disadvantage which reduce its useful life. There are various methods to increase the natural durability of wood and wood products and most of them using chemical reagents. In the past, the thermal ...
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Microbiological degradation of wood and wood products is one of the most important of disadvantage which reduce its useful life. There are various methods to increase the natural durability of wood and wood products and most of them using chemical reagents. In the past, the thermal modification has been used as a ecofriendly method in many times. In this research the effects of steam pretreatment on the fungal durability of particleboard were studied. Steam pre-treatment was applied on the poplar wood particles using a stainless steel reactor at four temperature levels (155, 165, 175 and 185 ºc) and three retention times (15, 30 and 45 min). The amount of hemicelluloses, acetone extractives of wood particles as well as EMC and Mass loss of test panels were measured.The results indicated that the steam pretreatment significantly decreased the amount of hemicelluloses of wood particles, EMC and mass loss of test samples where as the amount of extractives of wood particles increased.According to the results, the variation of Mass loss of particleboard test samples showed a significant correlation to the variation of EMC of test samples, hemicelluloses and extractives amount of wood particles when the wood particles thermally pre-treated at 165ºC for 30 minutes
Ghoncheh Rassam; Masoud Azadifar; Abolfazl Karegarfard; Faezeh Fazeli
Abstract
The purpose of this study was to examine the physical and mechanical properties of particleboard made using corn stalk. Mixtures of corn stalks and industrial wood particles at the ratios of 0:100, 30:70, 50:50, 70:30, urea-melamine formaldehyde resin at two levels of 10 and 12% (based on the dry weight ...
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The purpose of this study was to examine the physical and mechanical properties of particleboard made using corn stalk. Mixtures of corn stalks and industrial wood particles at the ratios of 0:100, 30:70, 50:50, 70:30, urea-melamine formaldehyde resin at two levels of 10 and 12% (based on the dry weight of the particles) and two press times of 5 and 6 minutes were used for the production of laboratory particleboard. Physical and mechanical properties including water absorption and thickness swelling after 24 hours soaking in water, modulus of rupture, modulus of elasticity and internal bonding were measured and the data were statistically analyzed. It was observed that the increase in corn stalk particles in the mixture resulted in reduction of water absorption, thickness swelling after 24- hours water soaking and the internal bonding. The modulus of rupture and elasticity of the boards were increased at higher ration of corn stalk particles. The higher dosage of resin and higher press time imposed significant effect on all properties boards and improving properties were reached. In general, comparing the produced boards properties with EN 312 requirements, the boards produced using 70% corn stalk particles, 12% urea-melamine formaldehyde and 6 minutes press time showed optimal properties.
Hanieh Ghasemi; Ahmad Jahan Latibari; Abolfazl Karegarfard; Amir Lashgari
Abstract
The impact of the addition of different amounts of canola straw to the composition of the hardwood particles for the production of particleboard was investigated. Four levels (0, 15, 30 and 45%) of Canola particles were added to hardwood particles and then particles were blended with 12% urea resin (based ...
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The impact of the addition of different amounts of canola straw to the composition of the hardwood particles for the production of particleboard was investigated. Four levels (0, 15, 30 and 45%) of Canola particles were added to hardwood particles and then particles were blended with 12% urea resin (based on the oven dry weight of the particles). Boards at three densities of 550, 600 and 650 kg/m3 were produced. The flexural and internal bonding strength and water absorption and thickness swelling after 2 and 24 hours immersion in water of the boards were determined using appropriate EN standard test methods. Addition of different amounts of canola particle to the hardwood particles did not change either modulus of rupture or modulus of elasticity of the boards, but the internal bonding of the boards was reduced. As the dosage of the canola particles increased, both water absorption and thickness swelling were reduced. Increasing the density of the boards increased both strength and dimensional stability.
Mohammad Mehdi Brazandeh; Hossein Hosseinkhani; Saeid Eshagi; Abas Fakhryan
Abstract
Abstract Regarding undesired effects of formaldehyde on the health of people and enviroment, it is desired to evaluate the amount of emission of this gas from a wood composite product in order to introduce a practical method for evaluating the amount of it,s emission from any other wood product. To do ...
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Abstract Regarding undesired effects of formaldehyde on the health of people and enviroment, it is desired to evaluate the amount of emission of this gas from a wood composite product in order to introduce a practical method for evaluating the amount of it,s emission from any other wood product. To do this, particleboards of Haloxyon persicum were prepared in three different moisture levels using urea-formaldehyde adhesive. Formaldehyde emissions were evaluated as p.p.m using desciccator method ASTM D 5582-00.The results show that formaldehyde emission is reduced by raising moisture gradient such as emission values were determined as 8.946 ppm, 6.312 ppm and 4.172 ppm for the particleboards with moisture gradients of 0, 2 and 4 percent, respectively. Increasing moisture gradient from 0 to 2 percent resulted in 29 percent and increasing moisture gradient from 2 to 4 percent resulted in 34 percent less formaldehyde emissions, respectively. In addition, comparison these amounts with standard values show that these particleboards should be only used in the outdoors and not be used in the indoors at any way.
Hossein Rangavar; Behzad Bazyar; Hamed Akbari
Abstract
Abstract : In this study, the possibility of using Cicer arietinum straw residues for manufacturing three-layer particleboards was studied.The amounts of Cicer arietinum straw in mixture with industrial particles were ( % 25:75),(% 40:60),(% 55:45) respectively.Urea formaldehyde (100%) and Melamin urea ...
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Abstract : In this study, the possibility of using Cicer arietinum straw residues for manufacturing three-layer particleboards was studied.The amounts of Cicer arietinum straw in mixture with industrial particles were ( % 25:75),(% 40:60),(% 55:45) respectively.Urea formaldehyde (100%) and Melamin urea formaldehyde at different ratios of MF / UF were used as binders. The resin were applied at two levls of (% 8,10) in core and two levels of (% 10,12) in surface layers, based on oven dried weight of particles. Mechanical and physical properties of boards ( Modulus of rupture, Modulus of elasticity, Internal bonding and thickness swelling and water absorption after 2, 24 hours soaking in water) were measured and data were analyzed, statistically. The results indicated that increase of Cicer arietinum straw lead to increase of bending strength and Modulus of elasticity. Also the increase of resin content and use of Melamin urea formaldehyde resin caused to improve mechanical and physical properties. In General, the use of Cicer arietinumstraw in mixture with industrial particles up to 55% , and resin content of (10,12%) in core and surface layers, resulted in producing boards with appropriate mechanicals properties which are suitable for interior uses.
ُSima Sepahvand; Saeid Ziaee Khosro Shahi; Tagi Tabarsa
Abstract
This study provides an investigation of particleboard manufacture using tannin-ureaformaldehyde adhesive. Test board samples were made with regard to various replacementpercentage of tannin–urea (levels of 0, 10, 20 and 30%) and press time (12 and 15 min) andtheir properties were determined. Achieved ...
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This study provides an investigation of particleboard manufacture using tannin-ureaformaldehyde adhesive. Test board samples were made with regard to various replacementpercentage of tannin–urea (levels of 0, 10, 20 and 30%) and press time (12 and 15 min) andtheir properties were determined. Achieved data were analyzed according to two sides factorialplan. The results showed that with replacement of 10% urea formaldehyde adhesive by tanninformaldehydeat both 12 and 15 min pressing times, thickness swelling (after 2 and 24 hoursimmersion in water) was decreased while internal bonding increased. There were no significanteffect on MOR and MOE values. In general, the results of present research showed thatreplacing the UF resin at lower levels of tannin is suitable as adhesive to manufactureparticleboard so that with replacement ratio of 90:10, the moisture properties of boards werevery close to permissible those of the exterior wood uses.
Abolfazl Kargarfard; Amir Nourbakhsh; Fardad Golbabaei
Abstract
The objective of this study was to investigate utilization of pomegranate pruning residues as the core layer of the three layer particleboard. The percentage of the pomegranate residues varied as 100, 65 and 35% in the core layer of the eucalypt particleboard and three resin levels of 8, ...
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The objective of this study was to investigate utilization of pomegranate pruning residues as the core layer of the three layer particleboard. The percentage of the pomegranate residues varied as 100, 65 and 35% in the core layer of the eucalypt particleboard and three resin levels of 8, 10 and 12 % (based on the weight of the wood particles) were applied in the core layer. Resin dosage in the surface layer was kept at 12 %. The strength and physical properties were measured and analyzed applying factorial model based on completely randomized design. The results revealed that if 65% pomegranate residues are used in the core layer, the modulus of rupture and modulus of elasticity were the highest and the combined effect of both variables on the properties were statistically significant. The highest value of the modulus of rupture and modulus of elasticity obtained in the case of 10% resin in the core layer and 100% pomegranate residues followed by 8% resin in the core layer and 65% pomegranate residues. The combined effect of both variables on internal bonding of the boards was statistically significant and the highest internal bonding was reached if 8% resin and 65% pomegranate residues were used in the core layer. The effect of resin dosage on thickness swelling after 24 hours immersion in water was statistically significant. The results indicated that pomegranate tree pruning could be used for the particleboard manufacturing.
Mohammad reza Ghaznavi; Mehran Rohnia; Abdolsaber Yaghmaeipour
Abstract
The possibility of estimating some acoustical properties of particleboard panels such as "Acoustical coefficient" and "Acoustical Converting efficiency" using vibrational non-destructive techniques was investigated. Particleboard plates with the dimensions of 50×50, 100×50 and 150×50 ...
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The possibility of estimating some acoustical properties of particleboard panels such as "Acoustical coefficient" and "Acoustical Converting efficiency" using vibrational non-destructive techniques was investigated. Particleboard plates with the dimensions of 50×50, 100×50 and 150×50 were used. For each plate, three replicated samples were prepared and after conditioning and the measurement of weight and dimensions, the flexural vibration test was performed on plate free-free test. In order to be ensured of the accuracy of the test, panels were converted to beams with the dimensions of 500×50×16 mm and then the same test was repeated on these samples. The results obtained from flexural vibration test of plates and beams were compared. The results indicated that it is possible to evaluate the Acoustic Coefficient and Acoustical Converting Efficiency factors with adequate accuracy using the testing method used in this study.
ُSima Sepahvand; Meysam Zahedi; Samaneh vilki; Taghi Tabarsa
Abstract
Tannins are the most desirable natural, renewable phenolic components which obtained from plant resources. The phenolic nature of tannins causes that this materials react with formaldehyde and form tannin-formaldehyde resins. In this study, the raw materials of wheat straw and forest woods were used ...
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Tannins are the most desirable natural, renewable phenolic components which obtained from plant resources. The phenolic nature of tannins causes that this materials react with formaldehyde and form tannin-formaldehyde resins. In this study, the raw materials of wheat straw and forest woods were used for producing of particleboard (with a ratio of about 50 to 50 percent) using phenol formaldehyde based on tannin. Tannin as a powder was added at 10 and 20 percent (based on dry weight of resin solution) to formalin 35% for glue making. Particleboards were made at two range of thickness, 10 and 16 mm and their properties of including bending strength, modulus of elasticity, internal bonding, thickness swelling and water absorption were measured. The results from this investigation showed that the strength properties of the made boards from combined wood chips were lower than those from pure wood chips. Also, increasing of tannin usage into phenol formaldehyde caused to increase internal bonding or adhesion, swelling and water absorption (2 and 24 hours) of the boards.
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.
Abolfazl Kargarfard
Abstract
The purpose of this study was to utilize rose flower stem residues in the core layer of particleboard. Three press temperatures of 160, 170 and 180 C and five percentages of rose stem pruning (0, 25, 50, 75 and 100%) in the core layer were used in the production of poplar wood particleboard. Mechanical ...
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The purpose of this study was to utilize rose flower stem residues in the core layer of particleboard. Three press temperatures of 160, 170 and 180 C and five percentages of rose stem pruning (0, 25, 50, 75 and 100%) in the core layer were used in the production of poplar wood particleboard. Mechanical and physical properties were measured and analyzed applying factorial experiment and complete randomized design.The results indicated that modulus of rupture (MOR) and modulus of elasticity (MOE) of the boards significantly decreased by increasing rose stem particles in the core layer and press temperature did not show any significant effect on MOR and MOE of the boards. However, the addition of rose stem particles in the core layer deteriorated the IB of the boards and the lowest value was attributed to 100% stem residues in core layer. Also, by increasing of rose stem particles in core layer, thickness swelling after 24 hours immersion in water increased significantly and showed irreversible behavior to IB of the boards. The results showed that the incorporation of this residues to particleboard furnish will not reduce the properties of the board and it met the standard requirements. Our finding confirmed that agricultural residues can be used in combination with conventional raw materials in particleboard production.
Reza Hajihassani; Hossein Hosseinkhani; Abolfazl Kargarfard; Fardad Golbabaei
Abstract
The impact of reeds residue addition on physical and mechanical properties of particleboard made from pomegranate pruning was investigated. Laboratory particleboard was made applying one of the three levels of press time (3, 4 and 5 minutes) and one of the four levels of reed ...
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The impact of reeds residue addition on physical and mechanical properties of particleboard made from pomegranate pruning was investigated. Laboratory particleboard was made applying one of the three levels of press time (3, 4 and 5 minutes) and one of the four levels of reed and pomegranate pruning mixture (1-100% reeds; 2- 75% reeds + 25% pomegranate pruning; 3- 50% reeds + 50% pomegranate pruning and 4- 25% reeds + 75% pomegranate pruning). Boards were made in three replicate and 36 boards were made. Boards were tested using relevant EN standard and results were analyzed based on complete randomized design (CRD) under factorial experiment. Results revealed that increasing of pomegranate pruning in the wood mixture imposed positive effect on MOR, MOE, IB and thickness swelling of the particleboard. The relevant values of MOR, and MOE of the boards produced using 25% reeds + 75% pomegranate pruning were determined as 16.20 MPa and 2533 MPa respectively. Also thickness swelling after for 2 and 24 hours soaking in water decreased from 17.51 and 33.21% to 9.33 and 16.84% respectively. Internal bond strength (IB) of boards made applying 3 minutes press time (0.17 MPa.) was higher than boards made pressed for either 4 or 5 minutes, which indicates that 3 minutes press time is the appropriate time to approach maximum MOR and minimum thickness swelling after 24 hours soaking in water.
Composite wood products
masoudreza habibi; Hossein Hosseinkhani; Saeed Mahdavi
Abstract
In this study, particleboard was produced using Mesquite (Prosopis juliflora) called Somr wood. Oven dry density of stem and branch wood was measured as 0.92, 0.72 g/cm3 whereas the bark weight percentage of stem and branch wood determined as 13.6 % and14 % respectively. The influence of raw material ...
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In this study, particleboard was produced using Mesquite (Prosopis juliflora) called Somr wood. Oven dry density of stem and branch wood was measured as 0.92, 0.72 g/cm3 whereas the bark weight percentage of stem and branch wood determined as 13.6 % and14 % respectively. The influence of raw material mixture (stem wood, branch wood, the blend of stem and branch wood, 50/50 w/w) and resin content 10% and 12 % (based on dry weight of the particle) on particleboard properties were investigated. Properties such as MOR, MOE, IB, thickness swelling after 2 and 24 hours immersion in water were determined according to EN standard. Except for MOE, the effect of raw material type on board properties was significant. Particleboards made from branch wood, had the highest MOR. Maximum IB was observed in boards made from the blend of stem and branch wood. With the exception of bending properties, the effect of resin content on all board properties was significant. Increasing the resin content improved board properties. The lowest value of thickness swelling after 2 and 24 hours immersion in water was obtained in particleboard made from stem wood
Composite wood products
Hamid Hatefnia; Aliakbar Enayati; Kazem Dosthosseini; Mohammad Azadfalah
Abstract
In this research the effect of steam pretreatment on the physical and mechanical properties of particleboard were evaluated. Steam pre-treatment was applied on the particles of poplar wood in a stainless steel reactor at four different temperature (155, 165, ...
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In this research the effect of steam pretreatment on the physical and mechanical properties of particleboard were evaluated. Steam pre-treatment was applied on the particles of poplar wood in a stainless steel reactor at four different temperature (155, 165, 175 and 185 ◦C) and three different retention time (15, 30 and 45 min). The obtained results indicated that mechanical properties include MOR and IB content of the particleboard decreased, whereas MOE increased initially then decreased with severity of treatment conditions. The physical properties of the board i.e. thickness swelling, water absorption and consequently dimensional stability were improved by steam pretreatment. The observed changes can be attributed to reduction in hemicelluloses content and hydroxyl groups within wood component.
Noraldin Nazarnezhad
Abstract
This research was conducted to investigate the posibility of producing particleboards using surface activation method of P. deltoides particles and then using cross-linking agents to bond wood particles. At first, nitric acid as an oxidative agent at different proportion including 0, ...
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This research was conducted to investigate the posibility of producing particleboards using surface activation method of P. deltoides particles and then using cross-linking agents to bond wood particles. At first, nitric acid as an oxidative agent at different proportion including 0, 3, 4.5 & 6 percent (based on OD weight of wood) and two assembly times of 0 and 1 hour was used. Black liquor at two amounts of 5 and 7 percent was used as cross-linking agent. The results indicates that using 6% nitric acid and 7% liquor had the best performance and that, the assembly time of 1 hour had negative effect on all properties. The ATR spectrum of treated samples showed the increase in the absorbtion rate at 1740 cm-1 related to COOH group as compared with control samples. In addition, the spectrum indicated that increasing oxidation increase absorbtion rate of COOH group.
