Research Paper
Jafar Ebrahimpour Kasmani; Saeed Mahdavi
Abstract
This research was carried out with aim of the effect of nano-clay (NC) content on mechanical, thermogravimetry (TG) and morphological properties of wood plastic composite (WPC) made of medium density fiberboard (MDF) and particleboard (PB) wastes and recycled polypropylene and polyethylene (HDPE). For ...
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This research was carried out with aim of the effect of nano-clay (NC) content on mechanical, thermogravimetry (TG) and morphological properties of wood plastic composite (WPC) made of medium density fiberboard (MDF) and particleboard (PB) wastes and recycled polypropylene and polyethylene (HDPE). For this purpose, wastes of MDF and PB at 50 wt.% , recycled PP and HDPE at 50 wt.%, maleic anhydride grafted with polymers at a constant level of 3 wt.% and nanoclay at three different levels 3, 6, and 9 wt.% were blended by two-wire extruder. Afterward, standard test pieces were made using an injection molding machine and their mechanical properties and TGA were investigated. Scanning electron microscope (SEM) was applied to investigate the quality of nanoclay particles dispersion in the matrice as well as how the lignocellulosic and polymers are bonded at the surface of bonding. The results showed that tensile and flexural strength and their modulus of HDPE and PB composite significantly were increased by adding NC up to 3 wt.%, but the strengths were dropped in WPC's by increasing of NC content at 6 and 9 wt.%. The notched impact strength of WPC has been totally decreased by NC addition that indicates more fracture surface on WPC's. SEM micrographs revealed that porosity and cavities in WPC's especially were decreased at 9 wt.% NC, whereas it is clear an inappropriate dispersion and aggregation of NC in WPC. The thermal stability of WPC's was slightly improved at 3 wt.% NC and the residual after combustion increased compared to the control.
Research Paper
khadijeh armand; ali ghasemiyan
Abstract
In this research, the effect of sodium peroxide and sodium hypochlorite on the chemical-mechanical pulp bleaching (CMP) has been investigated. For this purpose, unbleached CMP pulp was produced from Mazandaran wood and paper mill, and bleaching with hydrogen peroxide and sodium hypochlorite was carried ...
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In this research, the effect of sodium peroxide and sodium hypochlorite on the chemical-mechanical pulp bleaching (CMP) has been investigated. For this purpose, unbleached CMP pulp was produced from Mazandaran wood and paper mill, and bleaching with hydrogen peroxide and sodium hypochlorite was carried out in two levels of 3 and 4%, during both 60 and 90 minutes in 70°C at 8% consistency. In each treatment, 30 grams of pulp with hydrogen peroxide, sodium silicate, DTPA, sodium hydroxide and sodium hypochlorite for bleaching were prepared. In the following 60 gr/m2 hand sheets were prepared and the optical properties of hand sheets were measured and analyzed based on TAPPI.The results obtained from the review of optical properties of handsheets show that by increasing the bleaching time and the level of chemicals the optical properties was improved. So that the highest brightness and minimum yellowness were observed in the 4% and 90 minutes in bleaching whit hydrogen peroxide. the lowest opacity in the control sample. Resistance properties such as tensile, burst and tear strength of bleached paper were also increased.
Research Paper
Hossein Yousefi; Elyas Afra; Davood Rasouli; mahdi mashkour
Abstract
In this study, paper and nanopaper were first produced and then treated with dodecyltriethoxysilane to prepare water repellent cellulose paper and nanopaper were made using dodecyltriethoxysilane. As the result of silane treatment, the hydrophilic surface of paper and nanopaper converted to hydrophobic ...
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In this study, paper and nanopaper were first produced and then treated with dodecyltriethoxysilane to prepare water repellent cellulose paper and nanopaper were made using dodecyltriethoxysilane. As the result of silane treatment, the hydrophilic surface of paper and nanopaper converted to hydrophobic surfaceones. The micrographs of FE-SEM confirmed the nano-scale size of cellulose nanofibers. XPS results showed that the surface of specimens contains silane. With the treatment of silane, the water droplet contact angle increased to 104 and 153 degree in nanopaper and 153 paper, respectivelydegree in paper. Because of this, the surface of treated paper can be regarded as super hydrophobic surface. TGA confirmed that the ash content of treated specimens were higher than those of untreated ones and also it was revealed that the silane treatment made a multi-layers coating on the surface of specimens. The treated specimens showed less water absorption and higher mechanical properties than untreated ones. The silane coupling treatment made water hydrophobic surfaces onof cellulose paper and nanopaper made them water-proof which can led to the development of their applications for outdoorshumid conditions.
Research Paper
Amir Mollahassani; Amir Hooman Hemmasi; Habibollah Khademi Eslam; Amir Lashgari; behzad baziyar
Abstract
The aim of this study is to evaluate the dynamic and static of elastic properties of Fir wood joints. For this purpose conventional joints in woos industry including dovetail, tongue and groove beech wood (Abies alba.) joints with polyvinyl acetate (PVA) and cyanoacrylate (CA) adhesives were used. Dimensions ...
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The aim of this study is to evaluate the dynamic and static of elastic properties of Fir wood joints. For this purpose conventional joints in woos industry including dovetail, tongue and groove beech wood (Abies alba.) joints with polyvinyl acetate (PVA) and cyanoacrylate (CA) adhesives were used. Dimensions of research samples were determined 24×50×360 (mm) according to international standard (ISO No.3129), and the results indicate that the effects of joint type, adhesive type, joint size, and also retrospective joint size became meaningful at 5% level in dynamic and static tests. As the length of groove and height of dovetail and length of dowel increased in the joints, dynamic and static elasticity modules increased, and in terms of changes in elasticity modules of the research. Elasticity module for dovetail joint, as a result of the shape, having a homogenous joint texture, and also lack of extended adhesive line in the joint, is closer to un jointed samples (control group). Also cyanoacrylate adhesive improved elasticity features of samples compared to polyvinyl acetate adhesive as a result of higher tension resistance and faster coagulation. The results of the Student's t-test indicate that there exists a not significant difference between the mean of dynamic and the mean of static modulus of elasticity, not significance at 5% level and The Pearson correlation test indicate that the dynamic and static modulus of elasticity of the samples are significant at 5% level and are of positive correlation(+.0958) .With regard to the correlation of the results of dynamic and static tests, methods for non-destructive dynamic investigation may be regarded as appropriate alternatives to destructive static tests, in order to assess and classify woods.
Research Paper
soheila izadyar; Roghayeh Hamzezadeh; Davood Efhamisisi
Abstract
The aim of this study was to investigate the effect of poplar wood saturation with nano-wollastonite and nano-wollastonite-styrene mixture on fire resistance and mechanical properties of polymer wood. Populus deltoids with 4% nano-wollastonite and 75% methanolic solution of styrene monomer was saturated ...
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The aim of this study was to investigate the effect of poplar wood saturation with nano-wollastonite and nano-wollastonite-styrene mixture on fire resistance and mechanical properties of polymer wood. Populus deltoids with 4% nano-wollastonite and 75% methanolic solution of styrene monomer was saturated by vacuum-pressure method. Four different wood treatments with nano-wollastonite, styrene, simultaneous nano-wollastonite and styrene (one-step) by 1:1 ratio and finally, the initial wood saturation by nano-wollastonite and then styrene (two-stage treatment) were investigated. In this study, the fire resistance and mechanical properties of the specimens were investigated. The results showed that the weight loss of wood against fire in two-stage treatment (NW+St) was 61.38% and in one-stage treatment (NW/St) was 69.68% better than control. NW/St treatment flame durability was approximately equal to NW treatment and improved by 30% compared to control. The reduction of carbonized area in two-stage (NW+St) and one-stage (NW/St) treatments was 28.53% and 29.06%, respectively, which showed a significant decrease. The results of mechanical tests showed that the NW/St treatment had the highest value due to the presence of condensing material in parallel to the NW/St treatment which showed an increase of 57.41% compared to the control sample. The modulus of elasticity and disruption of NW/St treatment increased by 26.77% and 35.71%, respectively. In addition, resistance to hardness of NW/St treatment increased by 10.07% compared to control. Overall, it can be concluded that mixing nano-wollastonite with styrene, while increasing the polymer wood fire resistance, also improved the mechanical properties of the polymer wood.
Research Paper
Ramin Vaysi; Yousef Yousefi-golordi
Abstract
This study was aimed to investigate the effect of cellulose nano-fibers and chitosan on optical and mechanical properties of chemi-mechanical pulp. For this purpose, some of the bleached CMP pulp of Mazandaran Wood and Paper Industries (MWPI) were randomly selected as a control sample. In addition, ...
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This study was aimed to investigate the effect of cellulose nano-fibers and chitosan on optical and mechanical properties of chemi-mechanical pulp. For this purpose, some of the bleached CMP pulp of Mazandaran Wood and Paper Industries (MWPI) were randomly selected as a control sample. In addition, the cellulose nanofibers were used as a white gel at 3 levels of 0, 2, and 3%. The chitosan was then added to the CMP pulps suspensions at 5 levels of 0, 0.5, 1, 1.5, 2%, as well. Hand-sheets with a basis weight of 60 gr/m2 were prepared from the mentioned pulps. The optical and mechanical properties were then measured and compared using TAPPI standard test methods. The results showed that by adding chitosan, tear, tensile, burst and breaking length strengths, air resistance, yellowness, and greenness increased and brightness, Cobb 60 and a* factor decreased. On the other hand, with the addition of chitosan and nano-cellulose to CMP pulp, the tensile, burst, breaking length strengths, air resistance, Cobb 60, yellowness and a* factor increased and the tear, brightness, and opacity decreased. Moreover, the findings showed that by simultaneous adding 2% chitosan, 2% chitosan, and 3% cellulose nanofibers to the CMP pulp, most of the paper properties were improved. Therefore, it can also be introduced as the best treatment.
Research Paper
Ehsan Fatehi; Mehdi Rahmaninia; Amir Khosravani; Zeynab Iron
Abstract
In production of paperboards especially the ones with high grammage, limitation of pulp drainage will drastically reduce the speed of papermaking process. In this manner, one of the common ways to improving the drainage and subsequent increasing of machine speed is producing the multilayer paperboards. ...
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In production of paperboards especially the ones with high grammage, limitation of pulp drainage will drastically reduce the speed of papermaking process. In this manner, one of the common ways to improving the drainage and subsequent increasing of machine speed is producing the multilayer paperboards. Although sometimes these layers are connected to each other without applying any additives, but most of the time starch has been applied between the layers for improving the internal bonds of multilayer paperboards. In this study, the effect of spraying two kinds of starch commonly used in industry (native and oxidized starch) with different application dosages (0, 0.5, 1, 1.5 and 2 g/m2) was investigated. The top layer of double layered paperboard was made of recycled printing and writing pulp and the back layer was produced from old corrugated carton (OCC) recycled fibers. Grammage of each layer was set about 100 g/m2. The results showed that spraying native and oxidized starch improved all considered mechanical properties comparing the control sample (without spraying any additive). Also, the native starch indicated better results in comparison with oxidized starch. Moreover, in both native and oxidized starch, the best mechanical properties were observed with applying 1.5 g/m2 of mentioned additives.
Research Paper
Farhod Firouzbehi; Davood Efhamisisi; Yahya Hamzeh; asghar tarmian; Reza Oladi
Abstract
Pyrolysis acid or wood vinegar is a dark liquid derived from the condensation of steam and smoke emitted by thermal pyrolysis of wood or any other lignocellulosic material. In this study, a heating furnace was first designed to allow a precise temperature-time program. The wood from three ...
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Pyrolysis acid or wood vinegar is a dark liquid derived from the condensation of steam and smoke emitted by thermal pyrolysis of wood or any other lignocellulosic material. In this study, a heating furnace was first designed to allow a precise temperature-time program. The wood from three different species including oak, citrus and cypress were pyrolyzed under a specific temperature-time schedule. The smoke emitted from the furnace were cooled and condensed in a 20 m pipe using the flow of cold water, and then was dumped in a container as liquid. Pyrolysis was performed at three different temperature ranges of 200, 260 and 330 ° C. The obtained pyrolysis acids had different color and acidity depending on the temperature and species of wood used. Under the heating conditions used in this study, cypress had lower pyrolysis rate than hardwoods. The weight percentage gain of the treated beech and pine wood varied from 5 to 35%, which was depended to the wood species for treatment, the temperature as well as the wood used for pyrolysis. Acid pyrolysis at higher temperatures resulted in higher weight percentage gain. The acid pyrolysis obtained at lower temperature was leached at higher rates from treated wood. Also the wood types used for pyrolysis had significant effect on the amount of lechant from treated woods.
Research Paper
Amir Hossein Mehranfar; Amir Khosravani; Mehdi Rahmaninia
Abstract
As the papermaking fibers contain negative charge, therefore some polymer additives used in the pulp slurry, possess counter-ions (cationic polyeletrolyte). Meanwhile, due to increase of electrical conductivity (EC) in the suspension, the performance of many polyelectrolytes encounter some problems. ...
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As the papermaking fibers contain negative charge, therefore some polymer additives used in the pulp slurry, possess counter-ions (cationic polyeletrolyte). Meanwhile, due to increase of electrical conductivity (EC) in the suspension, the performance of many polyelectrolytes encounter some problems. Hence, according to the efforts for the water system closure, less raw water consumption, and therefore higher EC of the pulp suspension, how the performance of polyelectrolyte-based additives such as cationic starch-anionic nanosilica is adversely affected. In this due, the effectiveness of EC on the performance of the mentioned additive combination was investigated. The results confirmed that the EC negatively affected the performance of the wet-end additive system; although the amount of effectiveness was dependent on the type of the pulp property. Such that for low polyelectrolyte dosage and high EC, in certain properties, the positive effect of this additive system was not significant anymore. But, in the case of some other properties such as internal bond and freeness, despite of the negative effects of high EC, the performance of cationic starch-anionic nanosilica system was significantly remarkable.
Research Paper
Fardad Golbabaei; Reza Hajihassani; Kamyar Salehi; Asghar Tabei
Abstract
The aim of this study was to construct lightweight structures and reduce energy loss. The aim of this study was to produce cement wood or composite products by combining organic particles such as wood fibers and lignocellulosic materials with monolith. The investigated product consisted of cement wood ...
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The aim of this study was to construct lightweight structures and reduce energy loss. The aim of this study was to produce cement wood or composite products by combining organic particles such as wood fibers and lignocellulosic materials with monolith. The investigated product consisted of cement wood made from scrap wood fibers and poplar wood particle thickness of 20 mm on both sides of the structure and 10 mm thick unolith in the middle of the structure. Products manufactured by Unolite Cement will have a combination of cement and Unolite properties. In this study, according to the studied variables including lignocellulosic materials and amount of additive (such as calcium chloride (Cacl) at two levels of 3 and 5%, the best specimens were prepared using 10% lignocellulosic materials. The thickness of the specimens was uniform at the two monolithic surfaces and all fabrication conditions such as discharge rate, press pressure, coalescence rate were assumed to be uniform and constant.In static bending experiment the mean maximum load force for ordinary brick failure was 3933.26N and the mean. The maximum load for breaking the cement stick was 389/78 N, which was approximately It has 10% resistance to ordinary brick but ordinary brick breaks abruptly when fractured, while the monolithic brick is gradually broken and the insulation properties due to the cellulosic fibers and the monolith in it are higher than the ordinary brick due to its low resistance to use. Recommended in partitions.
