Research Paper
Pulp and paper
Ali Safizadeh; Hossein Jalali tarshizy; Hamidreza Rudi; Ali Partovinia
Abstract
Recycling necessity of different paper and board grades is clear from various points of view which is accompanied with huge value addition, especially in writing and printing papers. Mineral filler applicability and its more usage in papermaking are increasingly focused and for recycled pulp, include ...
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Recycling necessity of different paper and board grades is clear from various points of view which is accompanied with huge value addition, especially in writing and printing papers. Mineral filler applicability and its more usage in papermaking are increasingly focused and for recycled pulp, include binary advantages, which have recently researched. The characteristics of recycled fiber and interest in fillers, made the application of dry strength additives inevitable that natural and economical adhesives for this purpose are always seeking. In these regards, effects of precipitated calcium carbonate (PCC) and Soy Protein (SP) on recycled pulp from writing and printing waste papers were investigated. SEM micrographs proved PCC retention which is compatible with the paper Ash results, but ash percentage declined by filler more addition. SP improved initially filler retention originated from the recycled pulp and also the PCC retention. Preservation of the initially filler caused higher total retention in the presence of SP and the same effect is reportable in simultaneously utilization of PCC and SP compared to the SP absence. So, the recycled pulp total retention decreased meaningful in lack of SP. Polymeric and various functional groups in the SP biopolymer could be attributed for these results. SP employment improved freeness (CSF) of the recycled pulp up to 8% and was observed in the highest premixing of SP/PCC (15%). Replacing of recycled fibers by PCC also improved freeness, meaningful. The freeness results were proved by drainage time of the pulp in handsheet maker. PCC application in the all studied levels (10, 12, 15%) and its premixing by SP reduced the paper water absorbency, unmeaningful. However, the paper tensile index declined by PCC and SP consumption.
Research Paper
Pulp and paper
Moghadaseh Akbari; Hossein Resalati; Ahmad reza Saraeyan; Mohammad reza Dehghani Firoz Abadi
Abstract
During the paper manufacturing process, especially when mechanical pulp or recycled pulp used, a large amount of soluble and colloidal substances (DCS) are comprised and dispersed or dissolved in the process water. Accumulation of DCS during the papermaking operation with the increasing closure process ...
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During the paper manufacturing process, especially when mechanical pulp or recycled pulp used, a large amount of soluble and colloidal substances (DCS) are comprised and dispersed or dissolved in the process water. Accumulation of DCS during the papermaking operation with the increasing closure process water systems, can have a variety of deleterious effects on papermaking process and paper products. In this study, The effect of anionic trash neutraliziation was investigated by using different catcher anionic tarsh and also pulp washing (removal of anionic trash) on the CMP pulp and paper properties. After the initial preparation chemi-mechanical pulp (CMP), bleached long fiber kraft pulp and mixing the pulps with each other, filler of precipitated calcium carbonate (PCC) was added. Then a cationic retention aid That in this research has been cationic polyacrylamide were added to the mix. To neutralization of and reduce the negative effects of anionic trash, different levels of poly DADMAC with molecular weight 100000-200000 (0.025, 0.05, 0.1, 0.15%) and poly aluminium chloride (PAC) (0.1, 0.25, 0.5%) was added before adding of retention aid. Results showed that the use of different neutralizers imprived of zeta potential and drainage time of pulp, and increase of total retention; but reduces burst index of paper that was not significant statistically. CMP pulp washing and drainage treatment caused reducing COD and on the other hand reduced the amount of anionic trash with organic origin. Washing treatment pulp improved drainage time from pulp, total retention; but reduced burst index. Based on these findings, using cationic polyelectrolyte can introduce as a good strategy to reduce the harmful effects anionic trash and more retention suspension components.
Research Paper
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.
Research Paper
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%).
Research Paper
Pulp and paper
Abdolrahim Mohebalian; Ahmad Jahan latibari; Ajang Tajdini; Shadman Pourmosa
Abstract
In this research, the influence of two temperatures (60 and 90°C) and three dosages of sodium hydroxide (5, 7.5 and 10%, based on the dry weight) on hornbeam wood chips alkaline pre-hydrolysis and soda pulping was studied. Soda pulping of both pre-hydrolyzed and control chips were conducted applying ...
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In this research, the influence of two temperatures (60 and 90°C) and three dosages of sodium hydroxide (5, 7.5 and 10%, based on the dry weight) on hornbeam wood chips alkaline pre-hydrolysis and soda pulping was studied. Soda pulping of both pre-hydrolyzed and control chips were conducted applying constant pulping variables. The effect of pre-hydrolysis on hemicelluloses removal and sodium hydroxide consumption and pulp characteristic including total yield, reject, pulp freeness, kappa number, and pulp strengths were measured and statically analyzed. In case the effect of variable on measured property was statistically significant, then Duncan multiple range grouping of the measured property was arranged. The result revealed that pre-hydrolysis removed almost 4.2% (based on dry wood) of hemicelluloses of the wood and pre-hydrolysis demonstrated easier soda pulping delignification, due to weakening the lignin-carbohydrate bonds and both total yield, reject and kappa number were reduced. Tensile strength index of the pulp produced using pre-hydrolyzed chips war lower and as the dosage of sodium hydroxide increases, the tensile strength index was reduced initiated from the removal of hemicelluloses which is also lower than control pulp, Tear strength index of the soda pulp from pre-hydrolyzed chips was mildly reduced which is anticipated to be the consequence of fiber weakening and fiber breaking during cooked chips defibration. The effect of pre-hydrolysis variables on tear strength was not statistically significant. Based on the result of this study, hornbeam wood can be a potential source of bio-refining based on lignocellulosic material.
Research Paper
Pulp and paper
Farhad Zeinaly; Ali Kazemi Tabrizi; yashar Einollahi; Faraz Asadi Malek Jahan
Abstract
The first act to ameliorate bleaching process is the major elimination of lignin. Actually, the use of oxygen delignification stage before bleaching process is the essential stage in improving bleaching process and reducing process emission. In this study, the effect of conducting oxygen-delignifying ...
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The first act to ameliorate bleaching process is the major elimination of lignin. Actually, the use of oxygen delignification stage before bleaching process is the essential stage in improving bleaching process and reducing process emission. In this study, the effect of conducting oxygen-delignifying process under different process condition, on chemical, physical, mechanical and optical properties of kenaf bast kraft pulp was investigated. The kenaf bast kraft pulp with the kappa number of 22, 1154 ml/g viscosity, and 38% ISO brightness was prepared. Oxygen-delignifying treatments were carried out with three different temperatures of 90, 100 and 110°C, and two oxygen pressures of 5 and 7 bars, with and without magnesium sulfate addition. Results indicated that oxygen delignification treatment led to intense decrease in pulp kappa number, while the pulp viscosity did not change significantly. Results of measuring delignified pulp viscosity showed that the magnesium sulfate addition caused to prevention of pulp viscosity downfall. The increase in reaction temperature had a significant effect on the process improvement, but raising the oxygen pressure did not have a meaningful effect on the process. Also, the pulp brightness was increased about 7%.
Research Paper
Pulp and paper
Ghasem Asadpour; Hadi Boroshkian; Hossein Resalaty
Abstract
The purpose of this study is to investigate the effect of pH on cellulase enzyme activity on the drainage and strength properties of OCC pulp. Recycled OCC pulp was pretreated with consistency 0.4 percent, in constant condition the temperature is 50˚C, duration 1 hour and range pH:4-4.5, 8-8.5 with ...
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The purpose of this study is to investigate the effect of pH on cellulase enzyme activity on the drainage and strength properties of OCC pulp. Recycled OCC pulp was pretreated with consistency 0.4 percent, in constant condition the temperature is 50˚C, duration 1 hour and range pH:4-4.5, 8-8.5 with cellulase enzyme at three levels 0.1, 0.3 and 0.5 percent (according to paper pulp dry weight). The results showed that pretreatment of cellulase enhances the freeness of pulp in comparison with the control samples, but by increasing the concentration of enzyme, the freeness of pulp was reduced in pH:4-4.5 the highest freeness is at the level of 0.1 percent and in pH:8-8.5 at the level of 0.3 percent. Also, papers were evaluated for resistance properties. The results showed that the increase in the use of cellulase enzyme has increased the tensile and burst strength index. As, in the alkaline pH, the effect of the cellulase enzyme on the increase of these strength was higher than the acid pH. The OCC pulp strength tear index, only in low levels of cellulase enzyme and in acidic pH, increased strength was observed, but with increasing enzyme consumption, there was a decrease in tear strength. Also, for strength to crushing, there was no specific trend regarding the amount of enzyme and pH on enzyme function.
Research Paper
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.
Research Paper
Mechanical conversion of wood and wooden fittings
Fardad Golbabaei; Reza Hajihassani; Kamyar Salehi
Abstract
With full respect for the principles of linking wood and conservation project Eldar pine because having good mechanical properties and availability of a wood structure in the form of pavilions chose alcove to the octagon without internal column with computer software Sketch up of Alborz research center ...
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With full respect for the principles of linking wood and conservation project Eldar pine because having good mechanical properties and availability of a wood structure in the form of pavilions chose alcove to the octagon without internal column with computer software Sketch up of Alborz research center with trees and landscaping of the complex was built. In making these structures all stages of the preparation of the wooden parts of drying are quite principled and dried in the open air during the six months were roof wood structure with the use of Eldar pine just Lambe was made in setting up the ceiling of solar connection on an octagonal timber wood using mortise and tenon mode and auxiliary metal was used. Sliding windows can be made to occupy less space. After completion of the period of three months to review the different pieces in different parts of the structure and measurements of physical densities, shrinkage and swelling and mechanical testing of hardness and impact resistance and protection review different parts of the fungal infection and decay structures was investigated. Since shortly after the beginning of the measure is going to change in the early stages of measuring statistically Darnbvdh but in the last stage of a decrease in density of about 5% and reduce the hardness of about 8% were signs of shrinkage and swelling in various parts of it to be seen.
Research Paper
Asghar Tarmian; Marjan Ebrahimi; Reza Oladi
Abstract
In this research, the effects of vessel features, including vessel diameter, density and porosity on drying rate and casehardening of beech (Fagus Orientalis) and oak (Quercus castaneifolia) was investigated. For this purpose, flat-sawn boards with dimensions of 170×50×80 mm (L×T×R) ...
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In this research, the effects of vessel features, including vessel diameter, density and porosity on drying rate and casehardening of beech (Fagus Orientalis) and oak (Quercus castaneifolia) was investigated. For this purpose, flat-sawn boards with dimensions of 170×50×80 mm (L×T×R) were cut from the sapwood and were then dried in laboratory kiln at 50˚C and 50 % relative humidity to final moisture content of 8%. After drying, the severity of casehardening of dried boards was measured using prong test. For anatomical studies and measuring vessel features, white chalk and black marker method was used and scanned sections were analyzed using ImageJ. Pearson correlation was applied between vessel features and drying properties using SPSS software. Results showed that vessel proportion and porosity have more pronounced effect on the drying rate than vessel diameter and the latter feature can be ignored; as drying rate in the free-water domain was lower for oak having larger but fewer vessels than beech. Results also showed that correlation between casehardening and vessel diameter was significantly positive; however, a negative correlation was observed between porosity and casehardening.
Research Paper
Pulp and paper
Hasan Davodian; Ghasem Asadpour; Seyed majid Zabizadeh
Abstract
In this study, the comparison of the use two combination of additives including the use of nano silica with cationic starch and the use of nano cellulose with cationic poly acrylamide on the physical and strength properties of cotton based paper. For this purpose, the pulp of the chemical pulp of bleached ...
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In this study, the comparison of the use two combination of additives including the use of nano silica with cationic starch and the use of nano cellulose with cationic poly acrylamide on the physical and strength properties of cotton based paper. For this purpose, the pulp of the chemical pulp of bleached cotton fibers is made with a 45˚RS grade peroxide and then the additives with specified conditions (cationic starch 1 and 1.5%, nano silica 0.3 and 0.7%, nano cellulose 1, 2 and 3% and cationic poly acrylamide 0.3, 0.5 and 0.7%) added to it and in the end 70 grams of handsheets were made. Similary, the paper was evaluated for physical and strength properties. The results indicated that the combination of cationic poly acrylamide and nano cellulose did not have much effect on increasing the majority of chemical pulp strength of cotton. As the reduction density, tensile strength, strength to tearing and no signification effect on strength to cutting. While the use of cationic and nano silica starches has significantly increased the strength and density properties of pulp paper significantly. Therefore, considering the results of physical and physical tests, it is possible to use the combination of cationic starch and nano silica to increase the chemical properties of cotton pulp.
Research Paper
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.
Research Paper
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.
