Yahya Hamzeh; Shayan Barzagar; Sahab Hadjazi; Soheila Izadyar
Abstract
Mineral fillers are the second most important elements used in papermaking. Increasing filler content in writing and printing papers without decreasing the mechanical properties is always desired for enhancing the optical and printing properties and cost effective papermaking process. In this study, ...
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Mineral fillers are the second most important elements used in papermaking. Increasing filler content in writing and printing papers without decreasing the mechanical properties is always desired for enhancing the optical and printing properties and cost effective papermaking process. In this study, to increase the filler content in paper, calcium silicate was loaded by in situ precipitation on bleached bagasse fibers. The effect of reaction temperature on the loading and precipitation of calcium silicate on fibers was investigated using ash content measurement, XRD spectroscopy, SEM imaging and EDX analysis. Finally, the effect of treated pulp content on the physical and mechanical properties of pulp was investigated. Ash measurement results showed that calcium silicate precipitation in bleached bagasse fibers was achieved and the amount of calcium silicate loading increased with increasing the reaction temperature. XRD spectroscopy confirmed the formation of calcium silicate and calcium carbonate, and their precipitation in cell walls, lumen and interior spaces of the bleached bagasse fibers was confirmed by SEM imaging. The precipitated minerals on the fiber surface consisted of particles with various diameters. The EDX analysis confirmed the presence of silica and calcium in the treated fibers. With the constant basis weight of 80 g/m2, brightness and apparent density increased significantly, however the paper strength decreased by increasing the content of treated fibers in handsheet 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.
Pulp and paper
Mohsen Mohammadi Achachlouei; Fahimeh Yousefi
Abstract
Paper is a dominant tool that is traditionally used for recording human knowledge and cultural heritage. Paper as organic material is at risk of biodegradation processes by various microorganisms including fungi, which cause irreversible degradation, color modification and instability of the historical ...
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Paper is a dominant tool that is traditionally used for recording human knowledge and cultural heritage. Paper as organic material is at risk of biodegradation processes by various microorganisms including fungi, which cause irreversible degradation, color modification and instability of the historical papers. Thus, the utilization of appropriate conservation methods and restoration treatments to minimize the adverse effects of fungi on historical papers have received great attention. Recently, Benomyl as an antifungal revealed a significant inhibitory effect on the fungal growth on the historical papers. In this study, the effect of Benomyl on gall ink as a popular and important ink used in cultural heritage was investigated. In a first step of the evaluation, the gall ink was prepared based on the historical recipes and then was implemented on surface on filter paper. The prepared samples were dipped into 100 ppm Benomyl-ethanol solution and aged after drying. The effect of Benomyl on gall ink was evaluated by the pH values of aqueous extracts, CIE Colorimetry, paper strengths, FTIR-ATR spectroscopy and SEM microscopy. Results indicated that the Benomyl in concentration of 100 ppm had no adverse effect on the gall ink and paper surface. However, dipping of paper in the Benomyl-ethanol solution resulted in a significant loss of paper strengths. In order to overcome this problem, it would be necessary to use a suitable solvent or another technique such as spraying for surface application of Benomyl.
Chemical conversion
Atefe Rahimi; Ali Abdolkhani; Yahya Hamzeh; Sahab Hedjazi
Abstract
DOR:98.1000/1735-0913.1398.34.124.66.1.9.1580 Rice straw rice is one of the most important lignocellulose wastes in Iran and the world. In this research, rice straw as renewable lignocellulosic materials were used to produce nano-structural lignocellulosic aerogel. For this purpose, rice straw powder ...
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DOR:98.1000/1735-0913.1398.34.124.66.1.9.1580 Rice straw rice is one of the most important lignocellulose wastes in Iran and the world. In this research, rice straw as renewable lignocellulosic materials were used to produce nano-structural lignocellulosic aerogel. For this purpose, rice straw powder was first pre-treated in sodium hydroxide aqueous alkali solution and resulting gel form mixture was transformed into physically bonded lignocellulosic porous and ultra-lightweight aerogel through consecutive processes including freezing-thawing, solvent exchange and freeze-drying. The product properties including apparent density and total porosity were determined, and other physical and chemical properties were evaluated by SEM, FTIR, XRD, nitrogen absorption (BET) and DSC methods. The results showed that a significant amount of the rice straw compounds dissolved in aqueous alkali solution and removed during the subsequent stages of aerogel production. The resulting aerogel showed a nano dimensional structure composed of particles and interconnected nanofibers, which had a great chemical and physical difference from the original rice straw.
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.
Pulp and paper
Ali Ahmadi ladjimi; Mohammad Azadfallah; Mehdi Rahmaninia; Yahya Hamzeh
Abstract
Stickies is among the major challenges in paper recycling mills. This substance deposits on paper machine components and cause to break paper web as well as loss of end product quality. So, it is necessary to control the stickies and lessen its detrimental effects. It is known that cationic polymers ...
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Stickies is among the major challenges in paper recycling mills. This substance deposits on paper machine components and cause to break paper web as well as loss of end product quality. So, it is necessary to control the stickies and lessen its detrimental effects. It is known that cationic polymers as fixing agents can control the stickies efficiently. Therefore, the control of stickies of OCC pulp using a commercial cationic polymer called GL at 0.4, 0.8 and 1.2 percent based on oven dry weight of pulp at pH 4 and pH 5 were investigated. Macro- and microstickies, dissolved and colloid substances (DCS), turbidity, and drainage time were measured to evaluate GL efficiency and compared with control sample. The results indicated that GL dosing at 0.4 and 0.8 percent in pH 4 and 7 due to flocculation and fixing the stickies onto the fiber caused to decrease in macro stickies, microstickies and DCS while improved the drainage time. Although, no efficient performance was observed in controlling stickies at higher content of GL i.e. 1.2 percent. Generally, it is concluded that with consuming at desired pH and dosage content, GL can be used as efficient agent to control stickies in processing of OCC pulp.
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.
Pulp and paper
Hamed Sharifi tasco; yahya hamzeh; shademan pourmousa
Abstract
In this study dispersed deinked pulp (DIP) of Latif Company which includes a mixture of straw printers, mixed office waste (MOW) and mechanical recycle paper was used to investigate the effect of bleaching variables on pulp and paper properties. Six variables of bleaching process including the amount ...
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In this study dispersed deinked pulp (DIP) of Latif Company which includes a mixture of straw printers, mixed office waste (MOW) and mechanical recycle paper was used to investigate the effect of bleaching variables on pulp and paper properties. Six variables of bleaching process including the amount of hydrogen peroxide, sodium hydroxide, and sodium silicate, bleaching time, bleaching temperature and final pH were optimized in order to improve wet and dry tensile index of handsheet. Design Expert software was used for analyzing and modeling. Results in from of the central composite design (CCD) were investigated and response surface methodology (RSM) was modeled and analyzed. Optimized wet and dry tensile were obtained by appling 1.55% hydrogen peroxide, 1.55% sodium hydroxide and 1.55% silicate, 90 minutes bleaching time, 83 0C bleaching temperature, and final pH equal to 8.5. The result showed that bleaching variables affect significantly the optical properties sample as well as mechanical strength of paper, and also dry and wet tensile strengths can be improved by optimization of bleaching condition.
Pulp and paper
masoumeh mollaei; Mohammad Azadfallah; Yahya Hamzeh; faramarz khodaian chegini
Abstract
The Effect of Chitosan - Poly (vinyl alcohol) Coatings on Strength and Barrier Properties of Packaging PaperAbstract In this research the mechanical and barrier properties of hand-sheets made of virgin and recycled fibers were studied after coating by chitosan and poly (vinyl alcohol) polymer blends. ...
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The Effect of Chitosan - Poly (vinyl alcohol) Coatings on Strength and Barrier Properties of Packaging PaperAbstract In this research the mechanical and barrier properties of hand-sheets made of virgin and recycled fibers were studied after coating by chitosan and poly (vinyl alcohol) polymer blends. Therefore to evaluate coatings effects on barrier properties, water vapor transmission rate (WVTR), water absorbance, air resistance and grease proof of coated papers were determined. Moreover, mechanical strength including tensile strength and burst strength were measured. According to the results, the barrier properties and mechanical strength of coated papers improved dramatically than uncoated ones. The best results in WVTR and mechanical strength tests were obtained for coatings with the same ratio of polymers. On the other hand, coating with 75%chitosan - 25% poly (vinyl alcohol) composition exhibited excellent resistance against the grease penetration and water absorption.Keywords: Coating, chitosan, poly (vinyl alcohol), barrier properties, mechanical strength
Kamrava Pourhooshyar Ziabari; Javad Torkaman; Alireza Ashori; Yahya Hamzeh
Abstract
Physical and mechanical properties of lightweight cement blocks made from lignocelluosic fibers and rice husk ash (RHA) were investigated. The cement blocks were made using three types of natural fibers including old corrugated container (OCC), virgin kraft pulp and fiberboard fibers representing 25% ...
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Physical and mechanical properties of lightweight cement blocks made from lignocelluosic fibers and rice husk ash (RHA) were investigated. The cement blocks were made using three types of natural fibers including old corrugated container (OCC), virgin kraft pulp and fiberboard fibers representing 25% of dry weight of the block. Rice husk ash varied at 0, 25 and 50 WT% combined with 5 WT% CaCl2. Density, water adsorption and compressive strengths of blocks were measured and compared using a factorial experiment with two factors at three levels. The results showed the significant effect of fiber type on the properties of blocks. OCC fibers provided the highest density and compressive strength and had the lowest water adsorption. The density of blocks reduced at higher dosage of RHA varied from 0 to 50%, and the lowest water adsorption and highest compressive strength was obtained at 25% RHA charge. The interactive effects of raw material on the properties of cement blocks were significant and the optimum properties were obtained with OCC fibers and RHA at 25%. رص�" ��0#� pl� � همراه 5 درصد کلرید کلسیم در قالب طرح فاکتوریل دو عامله 3´3 و با سه تکرار، مجموعاً 27 بلوک سیمانی تهیه شد و دانسیته، مقدار جذب آب و مقاومت فشاری آنها مقایسه شد. تحلیل آماری مقاومت فشاری بلوکها نشان داد که اثر هر سه نوع الیاف در سطح 5 درصد معنیداری است. بهطوریکه بلوکهای ساخته شده از الیاف بازیافتی دارای بیشترین دانسیته و مقاومت فشاری و همچنین کمترین مقدار جذب آب بودند. البته اثر مقدار خاکستر سبوس برنج بر خواص بلوکها نشان داد با افزایش مقدار خاکستر از صفر درصد به 50 درصد، دانسیتة بلوکها کاهش مییابد، ولی بهترین نتایج جذب آب و مقاومت فشاری در میزان 25 درصد خاکستر سبوس برنج حاصل شد. بررسی اثر متقابل مواد استفاده شده بر خواص بلوکها نیز نشان داد که مقدار خاکستر سبوس برنج و نوع الیاف بر هم اثر معنیداری دارند و مطلوبترین بلوکها با استفاده از الیاف کاغذ بازیافتی و مقدار خاکستر سبوس به مقدار 25 درصد سیمان حاصل شد.
Iman Rashidi joibari; Mohammad Azad falah; Yahya Hamzeh; Hossein Resalatii; Saeid Mahdavi
Abstract
Mechanical and chemi-mechanical pulps such as CMP, due to the weaker strength properties, have found limited application in the production of high quality papers as compared with chemical pulps. Therefore, appropriate modification of such fibers could be used to overcome such deficiencies. This study ...
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Mechanical and chemi-mechanical pulps such as CMP, due to the weaker strength properties, have found limited application in the production of high quality papers as compared with chemical pulps. Therefore, appropriate modification of such fibers could be used to overcome such deficiencies. This study investigated the effect of cationic pretreatment of the CMP fibers to improve the potential of the fibers in paper production. First, fibers were treated by 20% sodium hydroxide, and then the fiber surface was cationized by grafting with one of the dosages of 5, 10 and 15% EPTMAC, based on fiber oven dry weights. The cationized fibers were mixed with 100, 20 and 40 % non-cationized fibers and the mixture was used to make hand sheets. The tensile and burst indices of the hand sheets were measured. The highest tensile and burst indices were measured on hand sheets produced containing either 20 or 40% fibers grafted with 10% cationic agent.
Pulp and paper
Mohammad Molaei; Aliakbar Enayati; Yahya Hamzeh; Maryam Rostaei
Abstract
A fundamental study was carried out to explore the canola stalks properties in order to increase the use of abundant agricultural residuals in pulp and paper production. In this study, the morphological, chemical composition and soda pulping properties of Canola stalks were investigated. The results ...
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A fundamental study was carried out to explore the canola stalks properties in order to increase the use of abundant agricultural residuals in pulp and paper production. In this study, the morphological, chemical composition and soda pulping properties of Canola stalks were investigated. The results showed that except the thicker cell wall, the morphological properties of Canola stalks fibers were comparable to those of nonwoods and hardwoods fibers. Chemical analysis indicated that Canola stalks contains lower amount of cellulose (44%), while the lignin, hemicelluloses and ash content of Canola stalks are comparable to other non-woods. In comparison with most of non wood fiber resources, soda pulping of Canola stalks required higher chemical charge and pulping time. Soda pulping of Canola stalks in 22% active alkaline and 100 min in max temperature produced pulp with 82.6% ISO of brightness The strength properties of bleached Canola stalks soda pulp include tensile index (Nm/g), burst index (kpam2/g) & tear index (mNm2/g) showed respectively 63.6, 2.22 & 4.9.
Pulp and paper
Yahya Hamzeh; Mohammad hassan Ekhtera; Ali Abdolkhani; Sohila Ezadyar; Kambiz Pourtahmasi
Abstract
In this study the effects of several parameters on the sizing efficiency of test liner using poly aluminum chloride and rosin under neutral condition in reverse and premixing sizing processes were investigated. The results indicated that the individual effects of poly aluminum chloride amount, rosin ...
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In this study the effects of several parameters on the sizing efficiency of test liner using poly aluminum chloride and rosin under neutral condition in reverse and premixing sizing processes were investigated. The results indicated that the individual effects of poly aluminum chloride amount, rosin amount, interval time as well as interaction effect of poly aluminum chloride -rosin amounts in both sizing processes affect significantly sizing performance. The most important variable was the poly aluminum chloride amount. The effect of poly aluminum chloride amount on the sizing efficiency depended on the properties of fiber surfaces. This study showed that the interval time on the sizing efficiency is significant. To obtain an identical degree of sizing, it is possible decrease the amount of poly aluminum chloride and rosin amounts by increasing the interval time. In addition, the results confirmed two different mechanisms involved in the premixing sizing process.
