Composite wood products
Akbar Mastouri; Davood Efhamisisi; Asghar Tarmian; AliReza Gholinezhad-Pirbazari; Mohamad Azad fallah
Abstract
Background and objectives: Surface modification and coating is one of the effective methods to increase the performance and service life of wooden structures. All kinds of super-hydrophobic techniques with a contact angle above 150 degrees and a sliding angle less than 10 degrees, in addition to creating ...
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Background and objectives: Surface modification and coating is one of the effective methods to increase the performance and service life of wooden structures. All kinds of super-hydrophobic techniques with a contact angle above 150 degrees and a sliding angle less than 10 degrees, in addition to creating high hydrophobicity, also improve the antimicrobial and other surface properties of the substrate. Nevertheless, resistance to mechanical and moisture damage are very important in connection with super-hydrophobic surfaces. Natural waxes are one of the efficient and healthy materials for creating a durable super-hydrophobic coating with high biocompatibility. In this research, nano-silica modified with non-fluorine alkyl materials in the presence of epoxy resin has been used to create superhydrophobic surfaces of birch wood (Betula pendula). Also, carnauba wax has been used to improve water repellency, self-cleaning property and durability in conditions of mechanical damage, humidity and harsh environments, comparatively.Materials and methods: Dodecyltrichlorosilane was used in the presence of toluene solvent for functionalizing and hydrophobicizing silica nanoparticles. A formulation containing 2% of modified nano silica and some epoxy resin was used by spray method to fabricate super-hydrophobic coating on birch wood. Also, the optimal amount of vegetable carnauba wax (Brazilian palm) was used as a reinforcing agent to make the nanohybrid formulation. Durability and stability to mechanical damage (sandpaper abrasion, water impact) and harsh environments (acidic, alkaline, ultraviolet rays and solvents) were investigated. Finally, the self-cleaning potential of the processed wooden surfaces was evaluated by qualitative (inclined surface) and quantitative (dropping) methods using edible liquids.Results: Both types of nanocomposite (without wax) and nanohybrid (containing wax) coatings caused the super-hydrophobicity on birch wood. The adding the optimal amount of carnauba wax to the epoxy-based nanocoating structure leads to a contact angle of 170 degrees and a sliding angle of less than 3 degrees by water drops. In addition, carnauba wax caused the stability and strength of superhydrophobic surfaces in aging and mechanical conditions. The highest level of stability in harsh environments was related to the hybrid nanocoating. The highest contact angle was observed for pomegranate juice and the lowest for milk. Also, the self-cleaning potential with various types of Fanta and Coca-Cola drinks on the superhydrophobic surface was successful.Conclusion: The use of carnauba wax increased the contact angle and decreased the sliding angle. The use of carnauba wax significantly improved the mechanical properties and water-repellency of the super-hydrophobic coating. The chemical nature and morphological structure of wax in the coating is the reason for this superiority. The super-hydrophobic surface made with nanohybrid coating in the presence of carnauba wax has the potential of self-cleaning, biocompatibility and stability in service conditions and can be used to protect all types of general surfaces in the field of food, especially lignocellulosic substrates such as wood and paper.
Composite wood products
Javad Torkaman; rouzbeh asadi khansari
Abstract
Fibre-gypsum board is a composite, in which fiber used as the reinforcement in the matrix of gypsum. The purpose of this article is to investigate the effect of different amounts of waste paper fibers on the strength, resistance and the fracture behavior of fiber-gypsum board. For this purpose, amounts ...
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Fibre-gypsum board is a composite, in which fiber used as the reinforcement in the matrix of gypsum. The purpose of this article is to investigate the effect of different amounts of waste paper fibers on the strength, resistance and the fracture behavior of fiber-gypsum board. For this purpose, amounts of zero, 5, 10, 15, 20, 25 and 35 percent of waste paper fibers have been used. The results of measuring bending strength, internal bonding and moisture absorption during one month exposure to 100% relative humidity show that increasing the percentage of fibers up to 20% has increased the mechanical properties. In general, By using twenty percent fibers the bending strength increased fifty percent and the internal bonding became double and half in comparison to the control samples. The load-displacement curve shows that an increase of 5 to 15 percent of fibers does not change the fracture behavior of the fiber-gypsum board and they had brittle fracture same as control samples. While in more substitution values, the flexibility increases and the failure becomes ductile. Therefore, the best conditions in terms of strength, resistance, and flexibility have been obtained in 20% replacement of gypsum with waste paper fibers.
Composite wood products
Mohammad Hamed; Babak Nosrati; Ali Shalbafan; Mohammad Dahmardeh Ghaleno; Saeid Reza Farrokhpayam
Abstract
In recent years, the most important challenge for wood-based compact producers has been an increasing demand for a variety of wood materials, raw material prices, and rising transportation costs. On the other hand, the use of lightweight elements in the manufacture of decoration and furniture has received ...
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In recent years, the most important challenge for wood-based compact producers has been an increasing demand for a variety of wood materials, raw material prices, and rising transportation costs. On the other hand, the use of lightweight elements in the manufacture of decoration and furniture has received much attention. The present study aimed at evaluating the effect of different levels of two variables on the size and amount of expanded polyurethane chips in the production of lightweight composite particle boards. To this end, the size of polyurethane particles at three levels (10, 5, and 15 mm) and their amount at four levels (10, 5, 0, and 15%) were chosen as research variables, and the amount of adhesive consumption, press pressure, board thickness, and final density were considered as fixed factors. The results showed that flexural strength, the flexural modulus of elasticity, internal adhesion, and thickness elongation increased significantly with increasing the size of polyurethane particles in the middle layer of the board, but the effect of size was not significant on the water absorption of the samples. Also, increasing the percentage of polyurethane in the middle layer increased the mechanical properties and improved the physical properties compared to the control sample, and it had the largest effect on the internal adhesion of the samples.
Composite wood products
Reza Jazayeri; Saeed Kazemi Najafi; Habibollah Younesi
Abstract
This study aimet at to use modified graphite materials as a multifunction additive in the UF resin for improving the properties of medium density fiberboard (MDF). For this purpose expanded graphite EG was synthesized from graphite using the Tsai et al (2011) method. Then, as-synthesized EG was intercalated ...
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This study aimet at to use modified graphite materials as a multifunction additive in the UF resin for improving the properties of medium density fiberboard (MDF). For this purpose expanded graphite EG was synthesized from graphite using the Tsai et al (2011) method. Then, as-synthesized EG was intercalated with manganese dioxide by Schwarz et al (1995) method and converted to MnO2-EG. Any additive was added to the urea formaldehyde resin in three doses of 1, 2 and 3% to make the relevant MDF panels with 750 kg/m3 nominal density. During the pressing time, the tT100oc parameter (time to reach temperature100○C) of the middle layer of the board under the influence of the additive was determined by a chromium-nickel-based thermocouple. The treatment of MnO2-EG3 (amount of 3% modified expanded graphite) showed the greatest effect in reducing tT100°C of the middle layer of the board by 22%. In addition, the elastic modulus increased by 68% as a result of this treatment. In addition, the elastic modulus increased by 68% as a result of this treatment. G and EG additives showed a higher degree of internal adhesion than that of MnO2-EG additive. In this regard, EG2 and EG3 treatments showed a 42% increase in internal adhesion and G2 treatment showed a 40% increase in internal adhesion. The effect of EG2 treatment in improving SW24 was greater than other treatments, so that it caused a 19% decrease compared to the control.
Composite wood products
Mohammad Farsi; Asghar Tabei; Fatemeh Maashi sani; masoud ebadi
Abstract
The purpose of this research is to investigate the physical and mechanical properties of the wood-plastic nanocomposite obtained from Raw and Functionalized carbon nanotubes (CNTs). For this purpose, wood flour at a fixed amount of 50%, Raw CNTs at three levels of 0, 1 and 2% and coupling agent at two ...
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The purpose of this research is to investigate the physical and mechanical properties of the wood-plastic nanocomposite obtained from Raw and Functionalized carbon nanotubes (CNTs). For this purpose, wood flour at a fixed amount of 50%, Raw CNTs at three levels of 0, 1 and 2% and coupling agent at two levels of 0 and 3% were used in HDPE matrix. Also, Functionalized CNTS were used to strengthen the efficiency of nanocomposites at 1 and 2% levels separately. The materials were mixed together in an internal mixer (Haake) and then the samples were made by a hot press machine. The results showed that by increasing the amount of CNTs from 0 to 2% wt, the tensile strength and modulus of the samples increased by 58.8% and 12.6% respectively, and water absorption and thickness shrinkage decreased by 54.5% and 19.4% respectively. Composites containing 2% wt of CNTs showed higher impact resistance compared to control samples. The coupling agent had a positive effect on the performance of nanocomposites. The physical and mechanical properties of the samples were significantly improved by adding the coupling agent and Functionalized CNTs. The results were also confirmed by scanning electron microscopy.
Composite wood products
Reza Hajihassani; Fardad Golbabaei; seyedeh masoomeh
Abstract
The aim of current research was to investigate effect of chemical treatment of poplar fibers on physical and mechanical properties of wood plastic composite. The samples were made from acetylated poplar fibers with different weight percent gains (WPGs of 0, 14.7 and 19.5%), two levels of fiber consumption ...
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The aim of current research was to investigate effect of chemical treatment of poplar fibers on physical and mechanical properties of wood plastic composite. The samples were made from acetylated poplar fibers with different weight percent gains (WPGs of 0, 14.7 and 19.5%), two levels of fiber consumption (30 and 40%) as well as two levels of MAPP (0 and 3%). The samples were physically and mechanically tested. Afterward, the results were analyzed based on a complete randomized design (CRD) under a factorial experiment. Results revealed that the acetylation causes reduction of water absorption and thickness swelling and also improvement of some mechanical properties. Moreover, the results showed that the utilization of MAPP increases physical and mechanical properties of wood plastic composite. The research results showed that increasing of fiber consumption from 30 to 40% enhances water absorption, thickness swelling, tensile strength, tensile modulus as well as bending modulus, and also causes reduction of bending strength and impact resistance.
Composite wood products
Salume Esmaeilzadeh Saeih; Habibollah Khademi Eslam; Esmaeil Ghasemi; behzad baziyar
Abstract
Abstract Effects of temperature, cellulose Nano fibers and Nano clay particles on mechanical, physical and morphological properties of biodegradable composites made of recycled thermoplastic starch biopolymer and regular mixed industrial sawdust are investigated. To this aim Cellulose Nano Fibers and ...
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Abstract Effects of temperature, cellulose Nano fibers and Nano clay particles on mechanical, physical and morphological properties of biodegradable composites made of recycled thermoplastic starch biopolymer and regular mixed industrial sawdust are investigated. To this aim Cellulose Nano Fibers and Nano Clay particles were selected to be 0, 3 and 5 weight percent and were added to prepared biodegradable composites by using internal mixer and samples prepared by injection molding. Mechanical properties including tensile modulus and strength, flexural modulus and strength were extracted at temperatures ranging from 23 ºC to 80 ºC. Impact test and water absorption and thickness swelling were also performed according to related standards. Results show that elevating the temperature drastically reduce mechanical properties. Nano Clay addition results in better mechanical properties except for impact and water absorption and thickness swelling are improved. Using 5% Cellulose Nano Fibers improves mechanical and morphological properties better than 3% addition. Dynamic mechanical thermal analysis revealed Nano composites samples with 5% Nano Clay and Cellulose Nano Fibers has higher storage modulus and glass transition temperatures in compare to pure composite samples. This Nano particles can be successfully used to improve properties and performance except for fracture resistance.
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.
Composite wood products
ali hasanpoor tichi; Fardad Golbabaei; hadi Ghasemi; mojtaba rezanezhad
Abstract
In this study, the effect of nano gel wollastonite on physical, mechanical and morphological properties of composites made of bagasse and cement has been investigated. The mixing ratio of bagasse as lignocellulosic material with Portland cement at three levels (15:85, 25: 75 and 35: 65%) and nano-wollastonite ...
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In this study, the effect of nano gel wollastonite on physical, mechanical and morphological properties of composites made of bagasse and cement has been investigated. The mixing ratio of bagasse as lignocellulosic material with Portland cement at three levels (15:85, 25: 75 and 35: 65%) and nano-wollastonite at three levels of 0, 3 and 7% were considered as the variables of this study. The cake density of all boards were 1.1 g / cm3 and calcium chloride booster 5% for all treatments were considered as constant factors. Mechanical and physical properties of the specimens include modulus of rupture, modulus of elasticity, internal bonding, thickness swelling after 2 and 24 soaking hours in water and density of boards according to DIN-EN-634 and fire resistance (weight loss percentage) according to standard ISO-11925 were measured. In this study, the hydration temperature of a mixture of cement, bagasse and nano-wollastonite was measured using a thermocouple and flux. Also, microscopic images (SEM) of samples were prepared to investigate the morphological properties of composites and their distribution. The results showed that by increasing the amount of nano-wollastonite, the percentage of weight loss boards decreased, the heat of hydration and the physical and mechanical properties improved. The modulus of rupture, modulus of elasticity, and internal bonding of boards decreased with increasing bagasse content and the maximum value was obtained using 15% bagasse. The results also showed that with increasing bagasse content in boards, there was a significant increase in thickness swelling of boards. Inference from microscopic imaging (SEM) showed that the optimum level of nano-wollastonite can fill the empty holes and create a uniform structure and thus improve the properties of the boards.
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
Fardad Golbabaei; Kamyar Salehi; Reza Hajihassani
Abstract
In this study, the composition of bagasse composite was investigated using different amounts of bagasse particles. Bagasse and cement particles are manufactured at levels (5, 10 and 15%) and percentage of calcium chloride as cement accelerating additive at two levels (3 and 2%) based on cement dry weight. ...
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In this study, the composition of bagasse composite was investigated using different amounts of bagasse particles. Bagasse and cement particles are manufactured at levels (5, 10 and 15%) and percentage of calcium chloride as cement accelerating additive at two levels (3 and 2%) based on cement dry weight. Then, the mixture was poured into a mold measuring 15 8 18 8 8 cm and the excess water was removed from the bottom of the mold and initially weighed 10 kg on the specimens. The specimens were removed from the mold after 48 hours and kept in a glass saturated room at 90% humidity for 14 days and then finally dried in a laboratory environment. The bending strength and physical properties tests were performed on the specimens. The results showed that bagasse particles had a significant effect on bending strength and other physical properties. The bending strength was highest in boards made with 10% bagasse particles.
Composite wood products
Moein Dehghan; Ali Ahmadi ladjimi; Habib Dahmardeh
Abstract
DOR:98.1000/1735-0913.1398.34.63.66.1.1575.1610 In the present research the biodegradability Properties of poly-lactic acid-canola stem flour composites in three levels of 25, 35, and 45% canola stem flour made by compression molding technique were studied . In order to study the biocompatibility behavior ...
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DOR:98.1000/1735-0913.1398.34.63.66.1.1575.1610 In the present research the biodegradability Properties of poly-lactic acid-canola stem flour composites in three levels of 25, 35, and 45% canola stem flour made by compression molding technique were studied . In order to study the biocompatibility behavior of the composite, three methods of biological degradation were used for Trametes versicolor and Gloeophyllum trabeum fungi, long-term water absorption and composites burial in the soil for 4 months. The results of statistical analyzes showed that the amount of composites weight loss increased against the degradation by fungi and burial in the soil by increasing the amount of rapeseed canola stem flour while pure poly-lactic acid had a very high durability against these factors. In addition, there was no effect on the weight loss of samples in the long run leach test so that the weight of composites and poly- lactic acid samples was constantly increasing and there was no effect on weight and thickness loss. The growth of myceliums fungi was clearly detectable and detectable in reviewing the images of electron microscopy from the fracture properties of composites, unlike poly-lactic acid so that fungi crossed their polymer into rapeseed shoot flour and reduced the weight of the composites. The results of the FTIR spectroscopy on poly-lactic acid prepared before and after exposure to the Gloeophyllum trabeum fungus confirmed the validity of the above results. According to the results of this study, poly-lactic acid, as a biodegradable polymer, has been shown to be very durable against degradation by natural biological agents.
Composite wood products
masoudreza habibi
Abstract
DOR:98.1000/1735-0913.1398.34.74.66.1.1578.1576 In this study, the effect of piling storage method of Bagasse was studied on the physical and mechanical properties of particleboard. Wet depitted Bagasse was used. In this study, Bagasse storage conditions included two moisture content (45% and 55%) and ...
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DOR:98.1000/1735-0913.1398.34.74.66.1.1578.1576 In this study, the effect of piling storage method of Bagasse was studied on the physical and mechanical properties of particleboard. Wet depitted Bagasse was used. In this study, Bagasse storage conditions included two moisture content (45% and 55%) and 4 storage times (1.5, 3, 4.5, 6 months). At the first, Bagasse chemical properties (pH, acid and alkaline buffering capacity) were determined. Then particleboards were fabricated. The physical and mechanical properties of the boards were measured and statistically analyzed. The results showed that at lower Bagasse moisture content, the sample pH and alkaline buffering capacity were decreased and acid buffering capacity increased. Also board bending properties (modulus of rupture and modulus of elasticity) and thickness swelling after 2 and 24 hours immersion in the water were reduced. Bagasse chemical properties tend to be acidic up to storage time of 3 month and the minimum of board bending properties and internal bond were obtained in this storage time. The physical properties of boards were improved with increasing of storage time.
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
Laya jamali rad; saeed Narooei
Abstract
The purpose of this study was to investigate the possibility of using tobacco stalk and industrial wood particles in particleboard industry as a waste material that is not consumed and discarded and has a low price, followed by a reduction in production costs from the way of choosing this raw material ...
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The purpose of this study was to investigate the possibility of using tobacco stalk and industrial wood particles in particleboard industry as a waste material that is not consumed and discarded and has a low price, followed by a reduction in production costs from the way of choosing this raw material was of low value. For this purpose, the particles of tobacco stalk and industrial wood particles with different ratios of 0:100, 30:70 and 60:40, using the amount of adhesive used 12% and 14% (based on the dry weight of the wood chips) and the press time of 5 minutes for the construction of the board was considered. Physical and mechanical properties including thickness swelling after 2 and 24 hours immersion in water and bending strength (MOR), modulus of elasticity (MOE) and internal bonding (IB) were measured and all data were statistically analyzed. According to the results of this study, the increase in tobacco stalk particles resulted in increased thickness swelling after 2 and 24 hours immersion in water and reduced bending strength, modulus of elasticity and internal bonding, but all boards had a European standard (EN). Increasing the amount of resin also had a significant effect on all the properties of the boards and improved the properties. In a general conclusion and by comparing the properties of the boards produced with the European standard (EN), showed that using 60% tobacco stalk and 12% urea formaldehyde resin can be produced particleboard with the desired properties. This is a positive result of using tobacco stalk as a type of agricultural residue and, consequently, the prevention of environmental pollution caused by the burning of these compounds.
Composite wood products
Abolfazl Kargarfard
Abstract
The of utilization corn stalk residues in combination with poplar wood for particleboard production is investigated. Four combinations of corn stalk and P.nigra particles (100% corn stalk; 75% corn stalk, 25% poplar wood; 50% corn stalk, 50% poplar wood and 25% corn stalk, 75% poplar wood) is used. Two ...
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The of utilization corn stalk residues in combination with poplar wood for particleboard production is investigated. Four combinations of corn stalk and P.nigra particles (100% corn stalk; 75% corn stalk, 25% poplar wood; 50% corn stalk, 50% poplar wood and 25% corn stalk, 75% poplar wood) is used. Two resin contents of 10 and 12% and two press temperatures of 170 and 180C is employed.
The results showed that increasing press temperature from 170 to 180C, decreased both MOR and MOE of boards and increasing resin content from 10 to 12%, improved MOR. When the ratio of poplar wood to corn stalk increases, both MOR and MOE of the boards increases and the highest values were reached at 50 and 75% poplar wood. Higher press temperature and lower ratio of corn stalk improved internal bond (IB). Higher press temperature, resin content and lower ratio of corn stalk, decreased thickness swelling. Based on the results, with application of either 25 to 50% corn stalk and press temperature of 170C, standard particleboard can be produced.
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.
Physics and anatomy
Farshid Basiji; Vahid reza Safdari; Ahmad Jahan latibari; Amir Nourbakhsh
Abstract
The objective of adding reinforcing fillers, such as natural fibers to plastics is to increase the strength compared with neat plastic and wood. In this research the effect of wood pulp fiber length (short, medium and long), aspect ratio and fiber content (27%, 37%, 47% and 0% (non-reinforced PP)) with ...
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The objective of adding reinforcing fillers, such as natural fibers to plastics is to increase the strength compared with neat plastic and wood. In this research the effect of wood pulp fiber length (short, medium and long), aspect ratio and fiber content (27%, 37%, 47% and 0% (non-reinforced PP)) with 3% maleic anhydride grafted polypropylene on wood plastic composites (WPCs) has been studied. Results showed that increased fiber length or aspect ratio and fiber content increases mechanical properties (tensile strength, tensile modulus and MOE). Impact strength had an inverse correlation with fiber content and fiber length, but fiber content was a much more important factor than fiber length for impact strength. The impact strength of composite of softwood pulps was much higher than wood floor composite plastic. The significant interaction between fiber length and fiber content, and the lack of a specific trend in the treatments made assessment of the effect of fiber properties on MOR difficult.
Composite wood products
Ashkaan Keshaavarz; Hossein Jalali Torshizi; Faranak Mohamadkazemi; Mojtaba Koosha
Abstract
Nowadays, research studies about optimal application of natural resources in products manufacturing instead of fossil and non-renewable resources are of utmost and ever growing importance. Cellulosic resources as the future reliance of Green products and also mineral mines as plenty, cheap and available ...
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Nowadays, research studies about optimal application of natural resources in products manufacturing instead of fossil and non-renewable resources are of utmost and ever growing importance. Cellulosic resources as the future reliance of Green products and also mineral mines as plenty, cheap and available materials, especially in Iran, are appropriate options for various products developing. Then, effects of cellulosic fibers and Rockwool fibers (0.25% and 0.5%) in the absence and presence (0.1% and 0.2%) of nano bentonite on conventional and specific properties of Epoxy composite were evaluated. Tensile strength (47.9 MPa), modulus of rupture (86.3 MPa) and modulus of elasticity (2100 MPa) for the mineral fiber/epoxy composite and bentonite/epoxy nanocomposite were higher than the cellulosic fiber/epoxy composite. However, cellulosic fiber/epoxy composite showed higher energy absorption of the ballistic impact with lesser damage area caused by the impact than rockwool/epoxy composite which provide better protection against the ballistic impact. In the presence of nano bentonite particles into the epoxy resin context, rupture and elasticity moduli and tensile strength were dependent on the type and amounts of the additives with superiority of the mineral fibres/epoxy nanocomposite than the cellulosic fibers ones. In contrast, the composites energy absorption caused by the ballistic impact and its damaged area were more successful and favorable in cellulosic fibers than the mineral ones. Somehow that the highest absorbed energy of ballistic impact (60.7 J) and the least damaged area (10.7 cm2) were achieved by the highest application of cellulosic fibers (0.5%) and nano-bentonite (0.2%).
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
Behzad Ghasemi; Farshid Faraji; Sahab Hedjazi
Abstract
Abstract In this research, the effect of using natural poly lactic acid polymer and the amount of MAPP coupling agent on the physical and mechanical properties of composite manufactured by sunflower stem flour was studied. For this purpose, three levels of PLA polymer including 50, 60 and 70% and tow ...
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Abstract In this research, the effect of using natural poly lactic acid polymer and the amount of MAPP coupling agent on the physical and mechanical properties of composite manufactured by sunflower stem flour was studied. For this purpose, three levels of PLA polymer including 50, 60 and 70% and tow levels of MAPP including 4 and 6 percent based on dry weight of polymer were used as variables. Then, the physical and mechanical properties of the test specimens including dimensional stability, resistance and tensile modulus, resistance and flexural modulus and impact resistance were measured. The results showed that increasing the amount of PLA polymer and reducing the share of sunflower stem flour and increasing MAPP up to 6 percent, increased the flexural, tensile and impact resistances and improved dimensional stability of the composites. But in contrast, the tensile and bending modulus of composites were reduced. However, by reviewing the results, it was found that the physical and mechanical properties of the composites made with this polymer and the particles of sunflower stem flour were competitive with other composites made with other chemical polymers and in some cases it was better than them.
Composite wood products
Hadi Ashtari; Mehdi Jonoobi; Maryam Yousefzadeh; Yahya Hamzeh
Abstract
In this study Poly vinyl alcohol (PVA) and cellulose nanocrysrals (CNC) composite nanofibers were prepared by electrospinning process. To dissolve PVA, the deionized water was used due to environmental friendly of PVA. The design of experiments (DOE) was done by the Taguchi method using the Minitab for ...
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In this study Poly vinyl alcohol (PVA) and cellulose nanocrysrals (CNC) composite nanofibers were prepared by electrospinning process. To dissolve PVA, the deionized water was used due to environmental friendly of PVA. The design of experiments (DOE) was done by the Taguchi method using the Minitab for optimization of electrospinning. Polymer concentration was determined in 4, 6, 8 and 10% by solvent weight. Bead-free fibers were produced in 8% PVA concentration. CNC were added to polymer in 0.5, 1, 1.5 and 2% by PVA weight and DOE was applied for Needle to collector distance (cm), polymer concentration (%), polymer feed rate (mh/hr.) and applied voltage (Kv) were defined as variables, again to reach the thinnest fibers. Nanocomposites were soaked in GA 50% concentration for 48 hrs. to prevent nanocomposites decomposition. SEM and FESEM were used for morphological characterization. Diameter of the fibers was analyzed by Image software. Tensile, Modulus of Elasticity (MOE), Tension, Porosity, swelling and dissolving of nanocomposites were examined. Chemical reactions were traced by FTIR. Fibers with 87±16 nm in diameter were achieved in 0.5% CNC, 22 KV, 0.3 ml/hr. and 20 cm. Swelling and and solubility of nanocomposites were significantly improved by GA. FTIR spectra shows hemiacetal bounds produced during GA soaking. MOE and tensile were improved by CNC addition meanwhile tension and porosity were decreased. Same results were obtained for GA soaked nanocomposites.
Composite wood products
Ali Hasanpoor tichi; Behzad Baziyar
Abstract
In this study the effect of nano gel wollastonite usage in three level (0 , 5 and 10 percent per dry by weight of the cement) and the mixture ratios of lingocellulosic material to cement in three level 10:90, 20:80 and 30:70 on physical, mechanical , microscopic and biological properties of composite ...
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In this study the effect of nano gel wollastonite usage in three level (0 , 5 and 10 percent per dry by weight of the cement) and the mixture ratios of lingocellulosic material to cement in three level 10:90, 20:80 and 30:70 on physical, mechanical , microscopic and biological properties of composite made from rice straw fibers- cement was investigated. Three replicates for each treatment and 27 experimental boards were manufactured. Specimens were prepared according to DIN- EN634 standard test methods to measure mechanical and physical properties. Mechanical and physical properties including static bending strength, modulus of elasticity, interior bonding(IB),water absorption after 2 and 24 hours immersion in the water , density and decay resistant (loss weight) were measured. Micro- structural properties of composites were evaluated by SEM images. The results showed that, bending strength , modulus of elasticity , interior bonding and density were significantly increased with increasing Nano gel wollastonite . Also, with increasing Nano gel wollastonite , dimensional stability and decay resistance were increased in comparison with the control sample. Results of scanning electron microscopy showed that the calcium hydroxide formed hydrated calcium silicate gel (C-S-H gel) after addition the Nano gel wollastonite . SEM images showed that the micro- structure of the boards were improved by increasing the nano- wollastonite content.
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
Abolfazl Kargarfard
Abstract
Abstract: The application of corn stalks in the production of oriented strand board (OSB) is investigated. Corn stalks strands were produced in three sizes of 50, 75 and 100 millimeters length and dried to reach 2% moisture content. Oriented strand boards were made using either urea formaldehyde, melamine ...
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Abstract: The application of corn stalks in the production of oriented strand board (OSB) is investigated. Corn stalks strands were produced in three sizes of 50, 75 and 100 millimeters length and dried to reach 2% moisture content. Oriented strand boards were made using either urea formaldehyde, melamine formaldehyde and phenol formaldehyde resin, and two press temperatures of 175 and 185 ° C. OSB boards using poplar wood strands, 100 millimeters long were also produced as control samples. The results of strength measurements of the boards were statistically analyzed using factorial experiment and completely randomized block design. The grouping of the averages was based on Duncan Multiple Range Test. The results showed that the effect of the resin type on the flexural properties and internal bonding of the boards is statistically significant and boards produced using phenol formaldehyde resin exhibited the lowest modulus of rupture, modulus of elasticity and internal bonding strength. However, the adhesive type did not statistically influence the physical properties. The strand length also statistically influenced the board strength properties and boards made using poplar strands showed higher strength compared to corn stalks strands. The thickness swelling of the poplar OSB was almost twice the values of corn stalks OSB but the water absorption of these boards was lower than of corn stalks OSB. Press temperature adversely affected the modulus of rupture and elasticity, but higher press temperature improved the internal bonding strength. Higher press temperature increased the physical properties of the boards.
