Research Paper
Pulp and paper
Mohammad Azadfallah; Hamid khodabandehlo; Amir abas Shayeghani akmal
Abstract
The properties of transformer electrical insulating papers are influenced by fiber chemical modification process. In this research, the effect of cyanoethylation of fibers and addition of cyanoethylated cellulose nanofiber (CNF) on dielectric properties including capacitance, dielectric ...
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The properties of transformer electrical insulating papers are influenced by fiber chemical modification process. In this research, the effect of cyanoethylation of fibers and addition of cyanoethylated cellulose nanofiber (CNF) on dielectric properties including capacitance, dielectric loss, insulation resistance, breakdown voltage as well as tensile strength of two grade of handsheets made of unbleached long fibers and its mixture with bagasse soda pulp (with the ratio of 1:1) were evaluated after impregnating with mineral oil. Cyanoethylation of CNF and pulp fibers was performed by grafting of acrylonitrile under alkaline condition at 40 ̊C and room temperature respectively. Then, the nitrogen content of cyanoethylated samples was determined using Kjeldahl method and degree of substitution (DS) was calculated. The results showed that cyanoethylation of pulp fibers and CNF decreased the capacitance and tensile strength of insulated papers. It was also observed that the chemical modification imposed slight effect on dielectric loss, but insulation resistance and dielectric voltage were increased.
Research Paper
Composite wood products
Saeid Ismaeilimoghadam; Afsaneh Shahraki; Fatemeh Dehdast; Samaneh Pourkarami
Abstract
The objective of this study was the evaluation of the addition of silica particles in composite on natural resistance and morphology of wood plastic composite against of white rot fungi (Trametes Versicolor). Wood flour at the ratio of 60% (w/w), polypropylene and 2 per hundred compound (phc) MAPP was ...
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The objective of this study was the evaluation of the addition of silica particles in composite on natural resistance and morphology of wood plastic composite against of white rot fungi (Trametes Versicolor). Wood flour at the ratio of 60% (w/w), polypropylene and 2 per hundred compound (phc) MAPP was mixed. Nano and micro silica at 0, 1, 3 and 5 (phc) were added as filler. The mixing process in internal mixer (HAAKE) was done and test specimens were prepared using injection molding. The test specimens were exposed to Trametes Versicolor fungi for 8, 12 and 16 weeks at 25 oC and 75% humidity according to BS 838:1961. Then the mass loss, long-term water absorption and humidity coefficient diffusion of the samples were measured. The formation of hydrogen bonds between silica and wood flour was determined by Fourier Transform Infrared (FTIR) spectroscopy and the morphology of composite was stydied using scanning electron microscopy (SEM). The result showed that with increasing period of samples exposure to fungi, the mass loss, long-term water absorption and humidity coefficient diffusion in wood plastic composite increased. However at higher silica, decay in the samples was decreased. The effect of silica nanoparticles on natural resistance of wood plastic composite was higher than sample containing silica micro particles. Infrared spectroscopy showed hydrogen bonds between wood flour and silica. The result of scanning electron microscopy showed that with increasing of exposure time to fungi, small and large cracks in composite were created. However increasing silica addition, these cracks were decreased.
Research Paper
Composite wood products
Alireza Beiazyat; Laya Jamalirad; Hedayat alah Aminian; Sahab Hejazi
Abstract
In this research, the effect of the wood filler content and coupling agent (MAPP) on the physical and mechanical properties of Polypropylene reinforced with palm wood flour from the annual pruning of palm leaves (Shahani species) composite, were studied. For this purpose, the palm wood flour in three ...
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In this research, the effect of the wood filler content and coupling agent (MAPP) on the physical and mechanical properties of Polypropylene reinforced with palm wood flour from the annual pruning of palm leaves (Shahani species) composite, were studied. For this purpose, the palm wood flour in three levels of 30%, 40%, 50% and two levels of Maleic anhydride grafted polypropylene 4% and 6% were used as variable factors. Then, the Physical and mechanical properties of samples, including thickness swelling after 2 and 24 hours of immersion in water, bending strength, bending modulus, tensile strength, tensile modulus and impact strength, were measured.The results showed that by increasing palm wood flour, the bending strength, tensile strength and impact strength were decreased but the thickness swelling, bending modulus, tensile modulus were increased. It was also found that by adding MAPP, thickness swelling, bending strength, bending modulus, tensile strength and tensile modulus were improved. The results revealed that at increased consumption of palm wood flour and adding coupling agent leads to improve quality of the interface and significant changes especially dimensional stability and MOE, are achieved.
Research Paper
Mechanical conversion of wood and wooden fittings
Mostafa Poozesh; Hamid Reza Mansouri; babak Nosrati; Alireza Samzadeh
Abstract
This objective of this investigation was to modify and improve the water resistance of urea formaldehyde (UF) bonded particleboard adding Boric acid to the resin. Four levels (1, 2, 3 and 4) of boric acid based on the dry weight of the bonder were added to the UF resin. Then these mixtures were ...
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This objective of this investigation was to modify and improve the water resistance of urea formaldehyde (UF) bonded particleboard adding Boric acid to the resin. Four levels (1, 2, 3 and 4) of boric acid based on the dry weight of the bonder were added to the UF resin. Then these mixtures were used to produce particleboard. Physical and mechanical properties were examined according to the ASTM, D1013-04. The results showed that the using of this additive increased the water absorption and thickness swelling resistance after 2 and 24 hours immersion in water. Also using this additive increased the internal bonding of the boards after 24 hours after immersion in water, compared to the control sample but in the case of dry samples, the internal bonding decreased compared to the control sample. However it was not lower than standard value. As the Boric acid levels increased to 2 percent, bending strength of the samples was increased compare to the control sample and after this level it was decreased. Also with increasing the levels to 4 percent, modulus of elasticity of boards were increased compare to the control sample
Research Paper
Pulp and paper
Mehrnoosh Tavakoli; saraeyan ahmad reza; hossein resalati; ali ghasemian
Abstract
The present study was carried out aiming to investigate the effect of using Deinked Mixed Office Waste Pulp (MOW) on the properties of Alkaline Peroxide Mechanical Pulp (APMP) from cotton stalk. APMP pulps was prepared using chelating agents such as Na2SiO3 and DTPA (control sample) and without ...
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The present study was carried out aiming to investigate the effect of using Deinked Mixed Office Waste Pulp (MOW) on the properties of Alkaline Peroxide Mechanical Pulp (APMP) from cotton stalk. APMP pulps was prepared using chelating agents such as Na2SiO3 and DTPA (control sample) and without these agents in two-stage pulping withL/Wratio 6:1(ml/g), 20 minutes impregnation time at 70 0Cfor firststage, 60 minutes impregnation at 75 0Cfor second stage. Also, pulp was preparedfrommixed office waste paper, whichweredeinked with conventional flotation and then each pulp was separately refined up to about 300 ml CSF. The handsheets were made from control sample pulps, APMP without chelating agents, MOW deinked pulp and mixing with 10%, 20% deinked pulp with control APMP. Physical and mechanical properties were determined using TAPPI standard methods. Deinked MOW pulp had the maximum values of density, brightness, strength properties and APMP pulp without chelating agents had the minimum values. Among mixed pulps, APMP pulp containing 20% deinked MOW pulp showed the maximum value of density, brightness, burst index and tear index.
Research Paper
Management and Economics wood
Mehdi Jonobi; Shabo Salehpoor; zhreh Araaznia; Yahya Hamzeh
Abstract
This study was carried out to investigate the effect of storage time on the color and chemical compounds of bagasse particleboard made. For this purpose, the three levels of stored and fresh bagasse from karoon particleboard Company were used. In addition, the chemical compositions ...
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This study was carried out to investigate the effect of storage time on the color and chemical compounds of bagasse particleboard made. For this purpose, the three levels of stored and fresh bagasse from karoon particleboard Company were used. In addition, the chemical compositions were determined according to the TAPPI test methods and also biometrical (slenderness ratio) was done using the fiber dimension measured by Franklin method. The results showed that the amount of lignin was different in the stored samples at three levels, but the difference in the amount of cellulose and extractive was not observed. The results illustrated that the color changes in the stored bagasse were more than fresh sample. Identification of the microorganisms in stored samples was done and results showed that most of microorganisms were bacteria and yeast. The results showed that the storage time can significantly effect the color and physical properties of stored bagasse.
Research Paper
Composite wood products
Habib alah Khademieslam; Mehdei Kalagar
Abstract
In this investigation, tensile and physical properties of polypropylene (as matrix)/wheat straw fiber/paper mill sludge (as filler) composites was studied. The ratio of wheat straw fiber/ paper mill sludge was selected as 40/0, 30/10, 20/20, 10/30 and 0/40 (w/w) were used. Also, for better ...
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In this investigation, tensile and physical properties of polypropylene (as matrix)/wheat straw fiber/paper mill sludge (as filler) composites was studied. The ratio of wheat straw fiber/ paper mill sludge was selected as 40/0, 30/10, 20/20, 10/30 and 0/40 (w/w) were used. Also, for better compatibility between the two phases 3% MAPP as coupling agent was used. Mixing process was done in twin screw internal mixer extruder, and then composite samples were manufactured by injection molding. Result indicated that the tensile modulus of elasticity improved with increasing fillers and also it was observed that the toughness of composite increased when compared to the pure PP, while due to the usage of more paper sludge, these properties was improved. Tensile strength of composite decreased with adding 40% wheat straw fiber, but with addition of sludge tensile strength increased significantly. Adding wheat straw in PP matrix and its hydrophilic properties resulted in the highest rates of water absorption and thickness swelling. However, adding paper sludge and lower amount of lignocellulosic material, and the compatibilizer noticeably decreased the physical properties due to better bonding between two phases.
Research Paper
Composite wood products
Alireza Sokhtesaraei; Sahab Hejazi; Laya Jamalirad; Mohammad Ahmadi; Sead behnam Hosseini
Abstract
In this study, the physical and mechanical properties of polypropylene composites reinforced with alkaline sulfite-anthraquinone, soda-anthraquinone and monoethanolamine-anthraquinone and chemical mechanical produced from non-extrated and pre-extracted bagasse with hot water were studied. MAPP coupling ...
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In this study, the physical and mechanical properties of polypropylene composites reinforced with alkaline sulfite-anthraquinone, soda-anthraquinone and monoethanolamine-anthraquinone and chemical mechanical produced from non-extrated and pre-extracted bagasse with hot water were studied. MAPP coupling agent (3%) was added and the performance of pretreated and unpretreated bagasse composites were compared. The ratio of the polypropylene and reinforcement material (pulp) was considered at 50/ 50 (w/w). The results showed that the pulping process has a significant effect on all physical and mechanical properties of produced composites. In general, composites containing chemical pulps showed greater dimensional stability and mechanical strengths but lower water absorption than that of mechanical pulp. Composites containing treated fibers with alkaline sulfite-anthraquinone and soda pulp had the highest mechanical properties and dimensional stability. Composites made from fibers in which hemicelluloses were extracted and then were treated with chemical pulping processes had the highest mechanical strength and dimensional stability among all of samples. The highest mechanical strengths and dimensional stability were observed in composites which were reinforced with treated fibers compared with control samples containing untreated bagasse fibers. In general, the results showed the superior physical and mechanical characteristics for pulp - plastic composites compared with wood flour plastic composites.
Research Paper
Composite wood products
Hassan Ziaei Tabari; Habibollah Khademieslam; Behzad Bazyar; Amir Homan Hemmasi
Abstract
A new kind of thermoplastic elastomer nano composite reinforced with nano cellulose fibers is reported. The first aim of this investigation was to study the interaction and dispersion of nano cellulose fiber into Pebax matrix. This copolymer is Polyether – b – Amide thermoplastic elastomer ...
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A new kind of thermoplastic elastomer nano composite reinforced with nano cellulose fibers is reported. The first aim of this investigation was to study the interaction and dispersion of nano cellulose fiber into Pebax matrix. This copolymer is Polyether – b – Amide thermoplastic elastomer which is synthetized from renewable resources, and its hydrophilic character allows it to interact with nano cellulose. The interaction and reinforcement effect of nano cellulose at 3 levels of nano cellulose (1%, 3% and 5%) were examined by Scanning electron microscopes (SEM), Fourier transform infrared spectroscopy (FTIR) and Mechanical tests (young module, elongation at break and impact resistance). The results achieved from these tests were indicating appropriate effects of nano cellulose fibers for the strong interaction and close contact with polyamide phase of Pebax polymer which caused high mechanical properties (at 3% of nanoellulose) in nano composites. The young module and impact resistance of nano composite were significantly increased.
Research Paper
Management and Economics wood
shahram tahmasebi; behzad bazyar; habibolah Khademi Islam; mohammad Ghofrani
Abstract
In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven Glass, Carbon and Kevlar fibers were used ...
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In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven Glass, Carbon and Kevlar fibers were used and hand lay-up was done by vinyl ester and epoxy resins. Results of load-displacement curve at yield point exhibited capability of the reinforcing layers in preventing joint opening to some extent under load. However, failure was observed at the joint due to picking fibers from wood surface or members fracture near the interface when loading increased. Since the reinforced zones of the joints by FRP show the maximum shear stress, consequently the separation of fibers from wood surfaces increased at these locations. The adhesion of FRP layers to joint surface was not appropriate due to difficult process of layering at right angle of joints followed by probable formation of air bubbles. The results of assessing FRPs reinforcing behaviour indicated that application of vinyl ester in comparison with epoxy as matrix exhibited better performance. In addition, glass and carbon fibers showed better performance than Kevlar fibers as reinforcing agents.
Research Paper
Mechanical conversion of wood and wooden fittings
Hamideh Abdolzadeh; Ghanbar Ebrahimi; Mohammad Layeghi
Abstract
In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven Glass, Carbon and Kevlar fibers were used and hand ...
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In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven Glass, Carbon and Kevlar fibers were used and hand lay-up was done by vinyl ester and epoxy resins. Results of load-displacement curve at yield point exhibited capability of the reinforcing layers in preventing joint opening to some extent under load. However, failure was observed at the joint due to picking fibers from wood surface or members fracture near the interface when loading increased. Since the reinforced zones of the joints by FRP show the maximum shear stress, consequently the separation of fibers from wood surfaces increased at these locations. The adhesion of FRP layers to joint surface was not appropriate due to difficult process of layering at right angle of joints followed by probable formation of air bubbles. The results of assessing FRPs reinforcing behaviour indicated that application of vinyl ester in comparison with epoxy as matrix exhibited better performance. In addition, glass and carbon fibers showed better performance than Kevlar fibers as reinforcing agents.
Research Paper
Composite wood products
Behzad Kord; Mehdi Roohani
Abstract
In this study, the synergic effects of cellulose nanocrystal and nanoclay on the biodegradation and migration behavior of composite films based on polylactic acid (PLA) were investigated. PLA and PLA-based nanocomposite films containing different loads of cellulose nanocrystal ...
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In this study, the synergic effects of cellulose nanocrystal and nanoclay on the biodegradation and migration behavior of composite films based on polylactic acid (PLA) were investigated. PLA and PLA-based nanocomposite films containing different loads of cellulose nanocrystal and nanoclay (0, 3 and 5 wt % each) were fabricated using a solvent casting method. In order to improve the compatibility and miscibility of the whole system with respect to PLA matrix, cellulose nanocrystal was treated with oleic acid. For evaluating the biodegradation and migration behavior of films, the enzymatic degradation, biodegradation, buried in soil and compost; and overall migration were tested. The results indicated that the biodegradability of the composites increased with the increase of nanoparticles in the enzymatic, soil and compost media. Besides, with the addition of cellulose nanocrystal and nanoclay to the polymer matrix, the overall migration of composites decreased. This could be due to a better adhesion of the nanoparticles to the polymer matrix, and the tortuousity of their path.
Research Paper
Composite wood products
Morteza Nazeryan; Vahid Moazemi; Rahim Mohebi gargari
Abstract
The aim of this study was the evaluation of treatment effect of giant reed (Arundo donax) (untreated, heat-treated and hot-water-leached treatment) used in core layer of sandwich panel, and also the effect of weight ratio of almond shell powder to melamine/urea formaldehyde at three levels (3:97, 18:82 ...
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The aim of this study was the evaluation of treatment effect of giant reed (Arundo donax) (untreated, heat-treated and hot-water-leached treatment) used in core layer of sandwich panel, and also the effect of weight ratio of almond shell powder to melamine/urea formaldehyde at three levels (3:97, 18:82 and 33:67 w/w) on the dry- and wet-pull off adhesion (after 2 hours immersion in boiling water) of sandwich panel. Statistical analysis and Duncan multiple range test showed that the type of treatment of core layer particle and the ratio of almond shell powder to melamine/urea formaldehyde statistically influenced the dry and wet-pull off adhesion. According to the FTIR spectra obtained from samples made from particle treated with hot-water, the hot-water treatment caused an increase in number of hydrogen bonds. Macroscopic photos, also, showed that hot-water treatment created the best surface quality in order to forming desirable bond. Generally, panel manufactured from hot-water-treated particles in core layer and 33% of almond shell powder in glue line had the highest pull off adhesion in dry (5.01MPa) and wet (2.86 MPa) conditions.
Research Paper
Composite wood products
Amir Norbakhsh; Abolfazl Kargarfard
Abstract
In this research the impact of micro cellulose particles length, and coupling agent (MAPP) on the mechanical and thermal properties of Nano/ wood plastics composites were investigated. The results showed that mechanical properties of the composites made with 50 micron micro cellulose particles and 5 ...
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In this research the impact of micro cellulose particles length, and coupling agent (MAPP) on the mechanical and thermal properties of Nano/ wood plastics composites were investigated. The results showed that mechanical properties of the composites made with 50 micron micro cellulose particles and 5 % of MAPP were significantly different to those of the lower length (20 micron) and 2.5% of MAPP. Addition of MAPP enhanced the mechanical and thermal properties of the blends, due to the improvement of interface bond between the filler and matrix of Nano/ wood plastics composites. The significant improvements in mechanical properties of the blended composites made with MAPP and NC were further supported by SEM and TEM micrographs. Nano/ clay particles distribution and thermo gravimetric analysis (TGA) indicated that the addition of 5% MAPP and the longer micro cellulose particles remarkably increased the thermal stability of the blends compared to other treatments of Nano/ wood plastics composites.
Research Paper
Pulp and paper
omid yazdani aghmashhadi; Ghasem Asadpoor; Esmaeil Rasoli garmarodi; Reza Imani
Abstract
Bank-note during in its lifetime exposed to different environments and various applicationns with high frequency. As it is confirmed in scientific studies, bank-note can be one of the most important and perhaps rarest of disease and parasites carriers in society. The goal of this study is evaluation ...
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Bank-note during in its lifetime exposed to different environments and various applicationns with high frequency. As it is confirmed in scientific studies, bank-note can be one of the most important and perhaps rarest of disease and parasites carriers in society. The goal of this study is evaluation of the appropriate solution for antibacterial banknote paper production using silver nanoparticles as an antibacterial agent and a cationic polyacrylamide as retention aid. Laboratory pulp of cotton fibers bleached with hydrogen peroxide with freeness of 34 °SR, consistency of 3.1% and neutral pH were prepared and then above additives were added with specified conditions (nano silver with 25, 50, 75 and 100 ppm with 0.3% percent cationic polyacrylamide) and finally 90 g/m2 standard handsheets made from above mentioned pulp. To verify the presence of silver particles in paper structure, the hand sheet papers were characterized by SEM. UV-vis spectrophotometric method was used to evaluate of antibacterial properties of paper. Also, papers were analyzed in strength and optical properties. The results showed that with increasing the silver nanoparticles consumption, paper strength properties and brightness were decreased, and opacity increased. The biological test results showed that the antibacterial properties of paper were improved with silver nanoparticles consumption. Based on the results of strength, optical and biological tests and also economic and environmental overviews, 25ppm consumption of nano-silver was determined as optimized treatment.
