Wood Modification and Wood Preservation
Hamid reza Zarey; Reza Hajihassani; seyedeh masoomeh; Kamyar Salehi
Abstract
Background and Objectives: Wood has some limitations in properties and applications due to its natural nature, which need to be modified. Wood modification is usually done with different aims and methods. One of the wood modification methods is thermal treatments in order to improvement of dimensional ...
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Background and Objectives: Wood has some limitations in properties and applications due to its natural nature, which need to be modified. Wood modification is usually done with different aims and methods. One of the wood modification methods is thermal treatments in order to improvement of dimensional stability and biological resistance. But, it is surely affected on physical and mechanical properties of wood. Wood thermal modification in presence of oxygen causes the oxidation of its chemical structure which leads to decrement of physical and mechanical properties. Therefore, elimination of oxygen in thermal modification can reduce its destructive effects. In current study, the effect of thermo-oil process on the function of white rot fungus has been investigated. Moreover, the effect of this process on engineering properties of birch and pine wood species was evaluated.Methodology: In this study, two wood species of birch (Betula sp.) and pine (Pinus sp.) cut into the desired timbers. Heat treatment of the prepared timbers was carried out in a cylinder which equipped to the pressure and vacuum system. Also, industrial recycled oil was used for heat treatment of the timbers. The temperature and time treatment were considered 195 °C and 5 hours, respectively. At the end of the process, the used oil was drained into the oil storage tank and the timbers were removed from the cylinder after applying vacuum. In order to investigation of biological resistance as well as physical and mechanical properties (water absorption and swelling, density, mass loss, bending strength, compression strength parallel to the grain and impact strength) test specimens were prepared from the treated and control timbers based on the standard. The SPSS software was used for statistical analysis. The results were statistically analyzed based on a One-Way ANOVA method.Results: Results revealed that thermo-oil treatment can reduce the functionality of white rot fungus and also its efficiency on physical and mechanical properties of both wood species. Moreover, the results showed that this process improved the physical properties and reduced the mechanical properties, except compression strength parallel to the grain.Conclusion: Thermo-oil treatment at high temperature causes structural changes of wood and affects its physical and mechanical properties. Also, the structural changes caused by heat treatment can be an effective and inhibiting factor to functionality of white rot fungus on physical and mechanical properties of wood.
Wood Modification and Wood Preservation
Seyedeh Masoomeh Zamani; Reza Hajihassani; Kamyar Salehi
Abstract
AbstractThe purpose of this study was to evaluate effectiveness of brown rot fungus on ash (Fraxinus Sp.) and spruce (Picea Sp.) thermo-wood and also thermally modification on fungal functionality. In first step, prepared wood samples of both species were heat treated under 212 ºC for 3 hours. Afterwards, ...
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AbstractThe purpose of this study was to evaluate effectiveness of brown rot fungus on ash (Fraxinus Sp.) and spruce (Picea Sp.) thermo-wood and also thermally modification on fungal functionality. In first step, prepared wood samples of both species were heat treated under 212 ºC for 3 hours. Afterwards, heat-treated and untreated wood specimens were exposed to brown rot fungus for 16 weeks based on EN 313 and the functionality of fungal destructive agent and also its effect on physical and mechanical properties were finally analyzed. The obtained results showed that the brown rot fungus has been more efficiency on untreated specimens in compared with thermo-wood in both two wood species and caused more destruction and mass loss. Moreover, the results revealed that some physical and mechanical properties include density, compression parallel to grain and impact strength of exposed heated specimens to brown rot fungus were more than unexposed heated specimens to this fungus. Evaluation of laccase activity which produced by brown rot fungus showed more its effect on controls than heat treated specimens in both wood species. Based on the results, thermally modification can generally causes improvement of biological resistance, reduction of some physical and mechanical properties as well as more stability of applied properties of ash and Picea wood which exposed to the brown rot fungus.
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.
Reza Hajihassani; Mohammad Sadeghipour ranjbar; Saman Ghahri
Abstract
The aim of current research was to investigate physical and mechanical properties of particle board made from pistachio lignocellulosic residue. The raw materials were prepared from Sirjan (Kerman province). Sample boards were made from pistachio lignocellulosic residue at two press time (4 and 5 minutes), ...
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The aim of current research was to investigate physical and mechanical properties of particle board made from pistachio lignocellulosic residue. The raw materials were prepared from Sirjan (Kerman province). Sample boards were made from pistachio lignocellulosic residue at two press time (4 and 5 minutes), two press temperature (170 and 180ᴼc) and three compositions (100 percent, 90:10 and 80:20 pruning residue to pistachio shell). The specimens were physically and mechanically tested as water absorption, thickness swelling, bending strength, modulus of elasticity and internal bonding. Afterward, the results were analyzed based on a complete randomized design (CRD) under a factorial experiment. Results revealed that pruning residues of pistachio trees can be used as suitable raw materials for particle board production. Moreover, pistachio shell can be used up to 10 percent in raw material composition, but physical and mechanical properties of boards will be reduced in higher consumption quantities.Keywords: Particle board, pruning residue, pistachio shell, composition, physical and mechanical properties
Reza Hajihassani
Abstract
The aim of current research was to investigate the effect of hydro thermo-mechanical treatment and also press conditions on the physical and mechanical properties of poplar wood (Populus deltoides). The wood blocks were initially treated hydrothermally at temperatures of 100°C for holding time of ...
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The aim of current research was to investigate the effect of hydro thermo-mechanical treatment and also press conditions on the physical and mechanical properties of poplar wood (Populus deltoides). The wood blocks were initially treated hydrothermally at temperatures of 100°C for holding time of 0, 60, 120 minutes. Afterwards, the densification process was carried out under a hot press at two phases 1- contact and 2- compression press, for temperature of 160, 180 and 200°C for 60 and 90 minutes. The wood compression set was adjusted for 40 percent based on the thickness (radial direction) of the blocks. The samples were physically and mechanically tested as density, springback after press, water absorption, thickness swelling, bending strength and modulus of elasticity. Afterward, the results were analyzed based on a complete randomized design (CRD) under a factorial experiment. Results revealed that physical and mechanical properties of samples were enhanced due to the combined hydro thermo-mechanical treatment. Results revealed that this process causes reduction of springback, water absorption and thickness (radial direction) swelling and also improvement of mechanical properties such as bending strength and modulus of elasticity.
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.
Physics and Mechanical Wood
Abdolrahman Hosseinzadeh; Fardad Golbabaei
Abstract
In this investigation physical and mechanical properties of oak (Quercus castaneaefolia C.A. Mey) in Sangdeh region of Caspian Forests were measured according to the ASTM Standard D-143-83 for small samples. Statistical analysis included the performing of factorial design and Duncan's multiple- range ...
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In this investigation physical and mechanical properties of oak (Quercus castaneaefolia C.A. Mey) in Sangdeh region of Caspian Forests were measured according to the ASTM Standard D-143-83 for small samples. Statistical analysis included the performing of factorial design and Duncan's multiple- range test.The results indicated that geographical direction on the stems were not significant sources of differences for physical and mechanical properties, but the effects of height of stems were great and statistically significant and in most cases properties decreased with increasing height.
Physics and Mechanical Wood
Fardad Golbabaei; Hossein Hosseinkhani; Amir Nourbakhsh; Abolfazl Kargarfard; Abas Fakhryan
Abstract
Most industrial production processes need cooling water to operate efficiently and safely. Refineries، steel mills، petrochemical manufacturing plants، electric utilities and paper mills all rely heavily on equipment or processes that require efficient temperature control. Cooling water system control ...
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Most industrial production processes need cooling water to operate efficiently and safely. Refineries، steel mills، petrochemical manufacturing plants، electric utilities and paper mills all rely heavily on equipment or processes that require efficient temperature control. Cooling water system control these temperatures by transferring heat from hot process fluids into cooling water. As this happens، the cooling water itself gets hot before it can be used again it must either be cooled or replaced by a fresh supply of cold water. The aim of this study was utilizing domestic wood in cooling towers structure. For this purpose، five wood spices included: Hornbeam، Oak، Alder،Populus and Tehran pine (Eldarica pine) and also five different regions with different climate، included: electric plant Montazer ghaem from Karaj near of Tehran، electric plant Loshan from north of Iran، electric plant Dorcheh Esfahan from center of Iran and petrochemical manufacturing plants Bandar emam from south of Iran، have been chosen. Sampling have been done and treated with CCA. All samples were put in the cooling towers and were tested during the study period. (Mechanical tests such as specific gravity، static bending، compression parallel to grain and hardness). Based on this study، the mechanical properties of these spices during last four years were done. At the fifth year of study، virtual damages have not seen where as significant difference have been achieved in aspect of mechanical properties. Among of theses wood spices، Populous and Pinus eldarica had minimum mechanical degrade and it should be noted that Pinus eldarica spices had better quality than populous spices.
Pulp and paper
Yaghob Mamizadeh; Jafar Ebrahimpour Kasmani
Abstract
In textile industry the bellow comb fibers are located in a range in terms of their length and diameter that it can be used as proper raw material especially in paper dough industries; therefore, present study tries to consider improvement of durable paper's properties made of cellulosic nanofibers. ...
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In textile industry the bellow comb fibers are located in a range in terms of their length and diameter that it can be used as proper raw material especially in paper dough industries; therefore, present study tries to consider improvement of durable paper's properties made of cellulosic nanofibers. In this consideration, the below comb fiber of pulp and paper imported chemical pulp are prepared from a company that is producing durable papers and they were transferred to laboratory. Cellulosic nanofiber has been prepared from Nano Novin Polymer Co., and it has been consumed at 4 levels of 0, 0.3, 0.6 and 0.6%. After mixing pulp with cellulosic nanofiber at determined percentages, the handmade 90 g.m-1 papers were made and eventually physical and mechanical properties of these papers were evaluated. The results showed that enhancement of cellulosic nanofibers till 0.9% has led to enhancement of tensile strength, bursting resistance, tearing strength and folding strength comparing to control sample up to 22.7, 38.9, 7.7 and 384% respectively. Increasing the amount of cellulosic nanofibers up to 0.9% the surface smoothness has increased up to 7.9% comparing to control; moreover, water absorption and pores were reduced as 69 and 7.9% respectively. The SEM results showed that enhancement of cellulosic nanofiber percentage has led to reduction of pores.
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
Mostafa Yahyavi; Abolghasem Khazaeyan; Alireza Shakeri
Abstract
Abstract The aim of this research is the possibility of using black liqour and nano Graphene oxide (GO) for making three-layer particle board. In this study, the amount of black liqour was as 0, 10, 20 and 30 percent and Graphene oxide was 0, 0.25 and 0.5 percent (based on oven dried weight of UF). Wood ...
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Abstract The aim of this research is the possibility of using black liqour and nano Graphene oxide (GO) for making three-layer particle board. In this study, the amount of black liqour was as 0, 10, 20 and 30 percent and Graphene oxide was 0, 0.25 and 0.5 percent (based on oven dried weight of UF). Wood particles was pressed with using a laboratory hydraulic press. Mechanical and physical properties (modulus of rupture, modulus of elasticity, internal bonding, water absorption and thickness swelling after 2 and 24h soaking in water) of the produced boards were measured according to EN standards. The effect of each of the variables was studied on the properties and analyzed at 95 percent with using SPSS software and variance analysis factorial design. The results showed that increasing black liqour resulted in decreasing the modulus of rupture, modulus of elasticity and internal bonding. The results also indicated that water absorption and thickness swelling after 2 and 24h soaking in water increased with increased black liqour and Graphene oxide percent. The results show that increasing of nano ghraphen resulted in increasing modulus of rupture, modulus of elasticity and internal bonding.
Composite wood products
Mohammad Zafari sarmori; saeid reza Farokhpayam; Ehsan Sanei; mohammad shamsian
Abstract
Although many studies have been done about the application of waste materials such as used plastics but returning of wood plastic products (Regrind) to the production cycle was rarely reported. In this work, the effect of once and twice regrind on the functional properties of WPC made from high density ...
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Although many studies have been done about the application of waste materials such as used plastics but returning of wood plastic products (Regrind) to the production cycle was rarely reported. In this work, the effect of once and twice regrind on the functional properties of WPC made from high density polyethylene (HDPE) has been studied. The specimens were fabricated with powder raw materials and by the flat press under laboratory conditions. HDEP and poplar wood flour were mixed with a weight ratio of 50-50 percent. The estimation of regrind process, physical and mechanical properties of boards were measured after each regrinding and also to evaluate of regrinding on filler particle size and the interface between the polymer and wood flour some Scanning Electron Microscopy (SEM) were prepared. The results of this research showed that regrinding of WPC leads to a decrease in mechanical properties including bending strength, flexural modulus, tensile strength and tensile modulus and on the other hand regrinding process leads to improved physical properties including water absorption and thickness swelling after hours. SEM photographs showed that during the process of regrinding, filler particle size is reduced while matrix surrounding the filler particles better.
Management and Economics wood
Reza Hajihassani; Behbood Mohebi; Saeid Kazemi Najafi; Parviz Navi
Abstract
Abstract The present research work has investigated the physical and mechanical properties of hygro-thermally modified poplar (Populus deltoides) wood. The poplar wood blocks were treated hygrothermally at temperatures of 130, 150 and 170°C and for 20, 40 minutes as holding time. The physical and ...
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Abstract The present research work has investigated the physical and mechanical properties of hygro-thermally modified poplar (Populus deltoides) wood. The poplar wood blocks were treated hygrothermally at temperatures of 130, 150 and 170°C and for 20, 40 minutes as holding time. The physical and mechanical properties were determined for both treated and untreated wood. The properties; mass loss, collapse, specific gravity changes, dimensional stability, surface roughness, bending strength and modulus of elasticity, were determined prior to and after the treatment in all wood blocks. As expected, the hygrothermal treatment significantly improved the dimensional stability of the samples. It was also found that the hygrothermal treatment could increase collapse, surface roughness and modulus of elasticity due to the treatment. However, there were decreases in wood mass, specific gravity and bending strength of the treated poplar wood. It was revealed that the mass loss, decrease in the density as well as collapse in woos is correlated with treatment temperature as well as the holding time. While, raise of the treatment temperature as the holding time caused increase of the dimensional stability.
Pulp and paper
Mohammad Ahmadi; Sahab Hejazi; Kamiar Salehi
Abstract
In this study, the effect of beating time on morphologic, physical and strength properties of soda and monoethanolamine pulps obtained from wheat straw was studied, in order to optimize the time for beating operation. Beating of the pulps was applied in different time by laboratory jokromill beater. ...
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In this study, the effect of beating time on morphologic, physical and strength properties of soda and monoethanolamine pulps obtained from wheat straw was studied, in order to optimize the time for beating operation. Beating of the pulps was applied in different time by laboratory jokromill beater. The results showed that rising time of beating leads to increasing the freeness (SR) of pulps and monoethanolamine pulp reached to maximum amount of freeness (SR) in less time as compared to soda pulp. In addition, it is found that monoethanolamin pulp obtained the maximum amount of tensile index (91.3 N.m/g) after 30 min beating time and after that longer time of beating process had no significant effect on increasing the tensile index. About soda pulp it is observed that tensile index was increased significantly by rising the time of beating process and for this kind of pulp, maximum amount of tensile index (87.7N.m/g) was obtained in 50 min beating process. The highest burst index for soda pulp was 5 Kp.m2 which was obtained by 50 min beating process. About mono ethanolamine pulp burst index increased by rising time of beating Process and reached to its maximum amount (5.6 Kp.m2) and after that its amount decreased. Rising the time of beating process led to decreasing the tear index in both of kinds of pulp consist of monoethanolamin and soda pulp. The results showed that mono ethanolamine pulp had the higher yield and better beating ability in comparison with soda pulp which can be caused by better ability for carbohydrates and minerals retaining in monoethanolamin pulp.
Composite wood products
Hossein Rangavar; Amir Nourbakhsh; Saeid Haji hatmlo
Abstract
The effects of nano-wollastonite on physical and mechanical properties of wood plastic composites made with dried sunflower stalks and alder wood flour, were studied. Five levels of sunflower stalk flour in ratio of the mass wood dry flour containing 0, 25, 50, 75 and 100 percent and nano-wollastonite ...
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The effects of nano-wollastonite on physical and mechanical properties of wood plastic composites made with dried sunflower stalks and alder wood flour, were studied. Five levels of sunflower stalk flour in ratio of the mass wood dry flour containing 0, 25, 50, 75 and 100 percent and nano-wollastonite Powder in three levels, 3, and 5% were considered as variables of the study. Physical and mechanical properties, perpendicular to the screw strength, bending strength, modulus of elasticity, water absorption and thickness swelling after 2 and 24 soaking hours in water were measured in accordance with the standard DIN- EN. In order to examine the intersection of wood and polymer as well as distribution patterns of nanoparticles in the polymer matrix microscopic photos were taken. The results showed that by increasing of sunflower stalk flour in the mixing with wood flour up to 25% increased resistance to screw withdrawal and up to 50 percent increase in flexural strength and modulus of elasticity of wood-plastic composites, respectively. Sunflower stalk flour mixed with alder wood flour increased water absorption and thickness swelling after 2 and 24 hours immersion in water. The use of nano-wollastonite up 5% in relation to the total mass of all the boards improved the physical and mechanical properties of wood-polymer composite.
Composite wood products
Saeid Esmaeiliymoghadam; Amir Nourbakhsh; seyed mojtaba Seyedzadeh Otaghsaraei
Abstract
This study with aim of evaluation the Nano-silica and wood flour calcareous-treated and evaluation of properties of the wood plastic Nano composite obtained from it performed. For this purpose beginning, wood flour was treated by calcium hydroxide and then with weight ratio of 60 to 40 by Polypropylene ...
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This study with aim of evaluation the Nano-silica and wood flour calcareous-treated and evaluation of properties of the wood plastic Nano composite obtained from it performed. For this purpose beginning, wood flour was treated by calcium hydroxide and then with weight ratio of 60 to 40 by Polypropylene with 4 per hundred compound (phc) MAPP compatibilizer in extruder machine were mixed. Beside, Nano silica with weight ratio of 0, 1, 3 and 5 phc was used. Wood plastic Nano composites were fabricated by injection molding technique. Fourier transform infrared spectroscopy was used from wood flour changes after chemical treatment and for morphological study of Nano composites from scanning electron microscopy and X-ray diffraction were used. Mechanical testes include bending (ASTM D790) and tensile (ASTM D638) and physical testes include water absorption and thickness swelling (ASTM D7031-11) on the samples was done. Results showed that by calcium hydroxide treatment, bending and tensile resistance were decreased but bending and tensile modulus were increased. Also with increasing the Nano silica up to specific range, the mechanical properties were improvement. Increase of Nano silica in untreated samples caused increasing of water absorption and in treated samples caused decreasing of water absorption. With increasing of Nano silica, thickness swelling in the samples was decrease. The results of infrared spectroscopy showed that after lime treatment No change has occurred in the absorption band related to the hydroxyl groups. Results of scanning electron microscopy showed that the needle-shaped crystals of calcium hydroxide formed calcium silicate crystals after addition the Nano silica too. As well as results of X-ray diffraction, confirmed calcium silicate crystals.
Composite wood products
Abolfazl Kargarfard; Amir Nourbakhsh
Abstract
AbstractThe objective of the present study was the utilization of cotton stalk residues for medium density fiberboard production. MDF was produced applying Three press temperatures (170, 180, and 190 oC ) and three pressing times (3,4 and 5 minutes) were used to produce medium density fiberboard (MDF) ...
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AbstractThe objective of the present study was the utilization of cotton stalk residues for medium density fiberboard production. MDF was produced applying Three press temperatures (170, 180, and 190 oC ) and three pressing times (3,4 and 5 minutes) were used to produce medium density fiberboard (MDF) from cotton stalks fibers. The properties of the laboratory boards were measured and the results are analyzed applying factorial experiment and randomized design. In case, the statistical difference was observed between the averages, then Duncan Multiple Range Test was used for grouping the averages. The results showed that as either press temperature or press time is increased, the modulus of rupture of the of the boards was significantly improved and the highest value was reached when 190 oC press temperature and 5 minutes press time was applied. The internal bonding of the boards was significantly higher when 180 oC press temperature was applied. The effect of press temperature on thickness swelling after 2 and 24 hours immersion in water was statistically significant and the lowest values were obtained when 190 oC press temperature was used. The results of this study indicated that the cotton stalks can be considered as a potential raw material for medium density fiberboard production and the properties of the boards meets the EN requirements.
Composite wood products
Hossein Rangavar; Abolfazl Kargarfard; Mohammad saleh Hosseini fard
Abstract
In this study, the effect of type II and III Portland cement and the use of undepithed and depithed sunflower stalks particles (Helianthus Annuus) with percentages of different mixing ratio of the poplar wood particles (Populous alba) with 100:0, 75:25, 50:50, 25:75 and 0:100 respectively in the manufacturing ...
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In this study, the effect of type II and III Portland cement and the use of undepithed and depithed sunflower stalks particles (Helianthus Annuus) with percentages of different mixing ratio of the poplar wood particles (Populous alba) with 100:0, 75:25, 50:50, 25:75 and 0:100 respectively in the manufacturing of wood-cement composites were studied. Physical and mechanical properties of boards were measured as the effect of lignocellulosic material (sunflower stalks andpoplar wood) and Portland cement type (II and III) on the cement setting time. The results of the study showed that the lignocellulosic material reduced the hydration reaction and increased cement setting time. In this regard, sunflower stalks particles in comparison with poplar wood particles increased cement setting time intensively. The boards made from type III Portland cement had better mechanical strength and physical properties (water absorption and thickness swelling reduced) than with type II Portland cement. In comparison with poplar wood particles usage, the use of sunflower stalks particles and more amount of it caused to mechanical properties decreases and increased the water absorption and thickness swelling after 2 and 24 h water immersion. Therefore the best characteristics were obtained in boards made from 100 percent poplar wood particles. In other hands, using depithed sunflower stalks particles caused to improved the physical and mechanical characteristics. In general, it can be concluded that 25 percent of depithed sunflower stalks particles relative to poplar wood particles (relative to mass lignocellulosic materials( with type III Portland cement in the manufactured wood-cement boards has suitable physical and mechanical properties for usage of these boards in interior building applications.
Composite wood products
Taherh Gholipor
Abstract
In this study the effect of type of polymer including polyvinyl chloride and high density polyethylene in production of wood plastic composite by using of canola straw waste in two forms, with and without pith (depithed), in combination with wood flour were investigated. Five levels of lignocellulosic ...
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In this study the effect of type of polymer including polyvinyl chloride and high density polyethylene in production of wood plastic composite by using of canola straw waste in two forms, with and without pith (depithed), in combination with wood flour were investigated. Five levels of lignocellulosic materials were used consisting of 100 % wood flour, 100% canola flour including pith, 100% depithed canola flour, 50% wood flour plus 50% canola flour with pith and 50% wood flour plus 50% depithed canola flour. Physical properties of boards including, thickness swelling and water absorption after 2 and 24 hours immersion in water and mechanical properties such as screw withdrawal strength perpendicular on the surface, flexural strength and modulus of elasticity according to EN were evaluated. The results of this study showed that wood plastic composite made of high density polyethylene had better physical and mechanical properties compared with polyvinyl chloride and using of canola flour combined with wood flour lead to increasing flexural strength and modulus of elasticity, but decreased screw withdrawal strength perpendicular on the surface. Using of lignocellulosic filler material by combining of 50% wood flour plus 50 % depithed canola flour combined with high density polyethylene powder can be produced wood plastic composite board with suitable physical and mechanical properties.
Composite wood products
Hossein Hosseinkhani
Abstract
Iran is not rich in forest land and only 7.5 per cent of country covered by forest. So Iran has to import wood based panel annually. It is estimated that 100.000.000 Date Palms trees covered an area at about 770.000 ha around world, and Iran has got 220.000 ha. Because of several reasons Date palm trees ...
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Iran is not rich in forest land and only 7.5 per cent of country covered by forest. So Iran has to import wood based panel annually. It is estimated that 100.000.000 Date Palms trees covered an area at about 770.000 ha around world, and Iran has got 220.000 ha. Because of several reasons Date palm trees should be pruned and each tree produce 10-20 kg residues annually. In this study, for making boards Date Palm pruning residues as raw material and employed UF resin as the binder. Steeming time (5 and 8 Min.), steeming time (135 and 145oC) and press time (1, 2 and 3 Min.) were used as variable factors and three boards were made in Pilot plant scale for each combination of variables. Samples of all made boards were tested by the methods of EN to obtain mean values of bending strength, and Internal bond strength (I.B). In addition samples of each type of board were tested for thickness swelling after soaking in water for 2 hours and 24 hours respectively. The results of this study show clearly that boards have higher mechanical properties than the MDF property requirements which is recommended by EN standard.
Composite wood products
Samaneh Mir; Saeid reza Farokh payam; Morteza Nazerian
Abstract
In this study the possibility of using urea formaldehyde and melamine urea formaldehyde with different ratios of formaldehyde and melamine for manufacture lightweight particleboard by expanded polystyrene (EPS) was investigated. Experimental panels were made with 30 percent lighter that common particleboard ...
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In this study the possibility of using urea formaldehyde and melamine urea formaldehyde with different ratios of formaldehyde and melamine for manufacture lightweight particleboard by expanded polystyrene (EPS) was investigated. Experimental panels were made with 30 percent lighter that common particleboard in 25 millimeters thickness and with wood particles that had been came from a factory. Urea formaldehyde and melamine urea formaldehyde with two ratios different of melamine to urea, 40 to 60 and 20 to 80 were types of adhesive. Analysis of data and obtained averages on physical and mechanical properties indicated the best combination of EPS and used resins. Amino plastics adhesives showed good compatibility result with expanded polystyrene. As reducing of the weight of the panel was the most important target in this work, internal bonding (IB) result showed it was done. Because there was no any chemical reaction between EPS and phenolic resin as adhesive, it’s using was unsuccessful. Preliminary results especially internal bonding and physical properties revealed this lightweight panel is proper for defined applications. Furthermore, using melamine urea formaldehyde as adhesive was positive effects on IB and the highest IB was for the panel made with this resin and minimum EPS content. In comparison of common panels, this new panel with maximum melamine content and hydrophobic EPS showed better results on IB and physical properties.
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.
Abdolah Elyasi; Kazem ِDosthosseini; Mehdi Tajvidi; Amir hossein Behravesh
Abstract
In this study, feasibility of foaming wood plastic composites using injection molding process was investigated. The effect of lignocellulosic raw material (Poplar saw dust and soybean straw flour) on the properties of composites was examined. Wood plastic composite boards with 3.2 mm thickness, 105 mm ...
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In this study, feasibility of foaming wood plastic composites using injection molding process was investigated. The effect of lignocellulosic raw material (Poplar saw dust and soybean straw flour) on the properties of composites was examined. Wood plastic composite boards with 3.2 mm thickness, 105 mm width and 105 mm length were prepared using high density polyethylene granules. The foaming agent (Azodicarbonamide) at 2 wt % was also used. The scanning electron microscope micrographs confirmed that foaming process has been successfully carried out. The Results showed that all mechanical properties (except the impact strength) decreased while water absorption increased as the microcellular foaming method was used. Adding soybean straw flour to the foam structure led to the decrease in flexural strength, flexural modulus of elasticity and tensile strength. Water absorption and thickness swelling were negatively affected with the addition of soybean straw flour.
Ebrahim HojatiMarvast; Ali Abdolkhani; Alinaghi Karimi
Abstract
Dissolution and Cellulose-Nylon composites preparation in liquid phase was studied. BMIMCl ionic liquid was synthesized in the laboratory and was used to perform the dissolution purpose. After the dissolution of the polymers, Cellulose and Cellulose-Nylon composite films were prepared and processed. ...
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Dissolution and Cellulose-Nylon composites preparation in liquid phase was studied. BMIMCl ionic liquid was synthesized in the laboratory and was used to perform the dissolution purpose. After the dissolution of the polymers, Cellulose and Cellulose-Nylon composite films were prepared and processed. Then the transparency, water absorption and thickness swelling, water vapor permeability and tensile strength of the composite were determined. Further characterization was performed using SEM and FTIR techniques. Results showed that both polymers were compatibly dissolved in Ionic liquid and homogenously blended which indicates chemical bonding was established between the polymers. Transparency, water absorption and thickness swelling decreased and water vapor permeability of the composites increased compared to pure cellulosic film. Also, mechanical strength, Young's modulus and strain at break point of the composite were decreased compared to reference cellulosic film.
Hossein Rangavar; Abdolrasool Oromiehie; Arsalan Safarpour; Taherh Gholipour
Abstract
The present study investigated the application of recycled polyvinyl chloride (PVC) in wood-plastic composite. Wood flour having the particle size of 150 mesh, was produced from a mixture of different hardwoods and used as filler at three levels of 30, 40, and 50% based on the dry-weight of the composite. ...
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The present study investigated the application of recycled polyvinyl chloride (PVC) in wood-plastic composite. Wood flour having the particle size of 150 mesh, was produced from a mixture of different hardwoods and used as filler at three levels of 30, 40, and 50% based on the dry-weight of the composite. Three types of PVC were used as the matrix (100% virgin PVC, 100% recycled PVC, and a mixture of the equal weight of virgin and recycled PVC). Maleic anhydride grafted polypropylene (MAPP) was used as the coupling agent at a fixed dosage of 5% based on the PVC weight. The composite panels were produced using injection molding and the physical and mechanical properties of the final boards were evaluated according to ASTM standard test methods. Results showed that the utilizing the mixture of virgin and recycled PVC increased the bending strength and modulus of elasticity. Water absorption was also increased. However, impact resistance and elongation at yield point were decreased. At higher wood flour content up to 40%, flexural strength was increase indicating that the resin properly encapsulated the wood flour particles and at higher wood flour dosage, elongation and Izod impact resistance was reduced.
