Pulp and paper
Saeed Mahdavi; Behnam Gholampoor
Abstract
Background and objectives: In addition to reducing the consumption of various resources such as water, energy, and wood, paper recycling is constantly increasing in different countries due to less pollution. One of the major defects of the old corrugated container (OCC) is its relatively weak strength, ...
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Background and objectives: In addition to reducing the consumption of various resources such as water, energy, and wood, paper recycling is constantly increasing in different countries due to less pollution. One of the major defects of the old corrugated container (OCC) is its relatively weak strength, which has limited its use in various sections of the packaging industry. In this study, the effect of using some additives was studied to improve the strengths of OCC to make the top liner of cartons in both wet and dry conditions.Methodology: OCC was prepared from domestically produced cartons. To determine the performance and optimal amount of additives, corn cationic starch (at 1, 1.4 and, 2%), wet strength resin (at 1, 2 and, 3%), AKD (at 1, 2 and, 3%), and imported tea envelope recycled long fiber paper (at 10, 15 and, 20%) were separately used as additives based on the dry weight of OCC pulp. The handsheets made by laboratory sheet former with a basis weight of 120 g/m2 and then tensile, burst, and tear indices were measured at wet and dry conditions to compare the effect of additives. Also, water absorption was measured by the Cobb test on the test samples. The optimal level of each additive was determined based on the results, then handsheets made from optimal combination treatment including appropriate levels of all additives, and different properties of handsheets were statistically compared.Results: The water absorption of handsheet was decreased by 90% compared to the control by adding AKD. This additive was able to decline the water absorption of handsheet made from OCC to about 20 g/m2 as the suitable range. The greatest increase of wet tensile strength of the handsheet was achieved using 3% wet strength resin compared to the control. The resin maintained the wet tensile, burst, and tear indices of the residual strength of handsheet by 25, 46, and 58%, respectively, compared to dry strengths so it has good performance. The results showed that by adding cationic corn starch and recycled long fiber paper, all the dry strengths of handsheet independently increased compared to the control. The optimal combination treatment was determined according to the independent use of additives in OCC pulp, including 1% cationic starch, 1% AKD, and 3% wet strength resin based on technical-economic considerations. There is no significant difference between dry tensile and burst strength of handsheet using this treatment and 20% recycled long fiber paper, which both means ranked statistically in the same group. Conclusion: The use of 20% recycled long fiber paper of tea wrapper has significantly improved the dry strength of OCC pulp, but adding 1% cationic corn starch to OCC pulp caused a few increases of dry strength. The wet strength of handsheet was significantly improved by adding 3% wet strength resin whereas 1% AKD significantly decreased the water absorption of the OCC pulp to 14 g/m2. The optimal combination treatment of chemical additives including 1% cationic corn starch, 1% AKD, and 3% wet strength resin improved the wet and dry strength of handsheet made from OCC pulp that could be used for packaging products that should be kept in refrigerator and freezer.
Chemical conversion
Saeed Hasani; Mohammad Talaei poor; behzad baziyar; Amir Homan Hemmasi; Saeed Mahdavi
Abstract
AbstractIn this study, black poplar (Populus nigra) cut from Zanjan province was used in two age groups of 18 and 38- year-old. Timbers with thicknesses of 4, 5 and 6 cm were prepared from each age group. The prepared timbers were modified during the heat treatment process (Thermowood) at a constant ...
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AbstractIn this study, black poplar (Populus nigra) cut from Zanjan province was used in two age groups of 18 and 38- year-old. Timbers with thicknesses of 4, 5 and 6 cm were prepared from each age group. The prepared timbers were modified during the heat treatment process (Thermowood) at a constant temperature of 212 °C. Experimental samples were obtained from the surface and middle depth of heat-treated timbers. Heat-treated and control wood samples were subjected to accelerated weathering for 150 hours. Color lightness (L*), color difference (ΔΕ*) and water droplet contact angle were measured for heat-treated and control samples before and after weathering. In order to investigation of the wettability content, the method of measuring the contact angle of the water drop - static according to the ASTM D 5946 standard was used. In general, before weathering, the brightness of the heat-treated samples decreased compared to the control sample, but after weathering, the color lightness of the control samples decreased and the color lightness of the heat-treated samples increased. Also, the content of color difference of samples after weathering compared to before weathering showed a significant decrease statistically. Heat treatment increased the contact angle of water droplets of the samples 60.31% and the contact angle of water droplets of the heat-treated and control samples increased significantly after weathering compared to before weathering.
Jafar Ebrahimpour Kasmani; Ahmad Samariha; Saeed Mahdavi
Abstract
This study was carried out to compare the individual and combined effects of nanolignocelluloses (NLC), cationic polyacrylamide (CPAM), cationic starch (CS) and imported chemical long fiber (LF) in the manufacture of recycle liner and fluting paper for packaging. Individual treatments of OCC were included ...
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This study was carried out to compare the individual and combined effects of nanolignocelluloses (NLC), cationic polyacrylamide (CPAM), cationic starch (CS) and imported chemical long fiber (LF) in the manufacture of recycle liner and fluting paper for packaging. Individual treatments of OCC were included 15% LF, 6% NLC, 1.5% CS and 0.15% CPAM as addetives. Combined treatments were included 6% NLC and 1.5% CS, 6% NLC and 0.15% CPAM. Handsheets were made with grammage of 127 g/m2 by application the mentioned treatments. Finally, the physical, mechanical properties and microscopic structure of handsheet were investigated. The results showed that addition of LF and NLC caused the density of handsheets decreased compared to the control. The individual and combined treatments led to increasing the tensile and burst strength of handsheet. Also, the tear strength of handsheet increased compared to the control except for the combined treatment of NLC and CS. FE-SEM images showed pores relative reduction in handsheet that prepared from combination treatments. It showed negative effect on water drainage. The addition of 6% NLC and 0.15% CPAM to OCC pulp resulted in the highest crush strengths as RCT and CMT compared to the control. SEM micrographs showed relatively reduced pores in handsheets prepared from combined treatments, which could have negative effect on the dewatering of OCC pulp.
Saeed Mahdavi; Mohammad Hadi Rezvani
Abstract
Kenaf as an industrial plant can play an important role in providing shortage of virgin fiber for paper and board based on the history of cultivation in Iran. Harvesting time of kenaf is one of the most important economic-technical aspect, so the growth rate of kenaf (variety of Cuba) and the weight ...
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Kenaf as an industrial plant can play an important role in providing shortage of virgin fiber for paper and board based on the history of cultivation in Iran. Harvesting time of kenaf is one of the most important economic-technical aspect, so the growth rate of kenaf (variety of Cuba) and the weight ratio of bast, core and pith individually were measured at 5, 6 and 7 months after planting and kenaf biomass was determined after 7 month. Soda-AQ pulping from kenaf bast fiber was adjusted at 14% and 16% chemical charges, 175°C, 120 min., liquor to bast fiber of 5:1 and adding 0.2% AQ. Handsheet was made by the bast pulp from the three harvested times with base weight of 110 g/m2. The results showed that by increasing the harvest period from 5 to 6 and 7 months, stalk height and diameter increased 9% and 5%, and vice versa, respectively. The weight ratio of kenaf bast to core has decreased by increasing of harvest time. Dry and green biomass of kenaf was determined at 33.1 and 7.7 t/ha, respectively. Screen yield, kappa number, and reject were of pulp were measured for combinations of optimal cooking in range of 48.8% to 52.9%, 35.4 to 72.6, and 0.92% to 2.5%, respectively. The beating energy consumption of pulp that prepared from 7 month harvesting time was greater than the others. Optimal conditions were determined as harvesting time of 5 month and cooking variables of 120 min, 165 °C and 16% NaOH for carton top liner. Handmade paper properties compared to kraft liner paper confirms the superiority of paper made from virgin kenaf bast fiber according to national standard of Iran (ISIRI 3054).
Masoudreza Habibi; Saeed Mahdavi; Vahid Pezeshki; Farshid Niromand; Hossein Familian
Abstract
This study was carried out to investigate the effect of Bagasse alkaline treatment (hydroxide sodium) on Medium Density Fiberboard (MDF) properties. For this purpose, wet depitted and storage bagasse was used. Cooking process was done for fibers preraring in 10 liters digester. Liqure to bagasse ratio ...
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This study was carried out to investigate the effect of Bagasse alkaline treatment (hydroxide sodium) on Medium Density Fiberboard (MDF) properties. For this purpose, wet depitted and storage bagasse was used. Cooking process was done for fibers preraring in 10 liters digester. Liqure to bagasse ratio was 10 to 1. Hydroxide sodium content was 0%, 4% and 5% based on oven dry weigth of bagasse. Cooking time and temperature were 5 min and 170 centigrade respectively. Fiber slides were obtained by using optical microscope. Chemical components such as holocelloulose and lignin contents were determined. Liqures pH was mesearued before and after cooking. Urea formaldehyde resin was used for MDF producing. Resin content was 12% based on oven dried bagasse. Bending properties (MOR & MOE), internal bonding and thickness swelling of the boards were determined based on EN-310, EN-319 and EN-317 respectively. The results showed that when using 4% alkaline treatment, were seen the minimum fibers cutting and crusing. With increasing of hydroxide sodium content, lignin content decreased and holocelloulose increased. Bulk density increased when increasing hydroxide sodium content. The maximum MOR, MOE and internal bonding of the boards were obtained in 4% hydroxide sodium content. Also thickness swelling of the boards was minimum.
Saeed Mahdavi
Abstract
The aim of this study was to solve the environmental problems caused after the bleaching of bagasse pulp by hypochlorite sodium in Pars paper mill. For this purpose, ECF bleaching method was used by performing OQPDEP sequence. The properties of bleached paper were compared to the bagasse unbleached paper ...
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The aim of this study was to solve the environmental problems caused after the bleaching of bagasse pulp by hypochlorite sodium in Pars paper mill. For this purpose, ECF bleaching method was used by performing OQPDEP sequence. The properties of bleached paper were compared to the bagasse unbleached paper as control and some paper properties that made from bagasse bleached pulp by EH sequence in Pars paper mill. The results showed that increasing the bleaching time of bagasse pulp from 30 to 120 minutes by oxygen had no significant effect on paper brightness, but paper density, burst and tear indices decreased. Pulp bleaching by O1QP3D(EP) sequence compared to bagasse unbleached paper led to the paper brightness of about 75% ISO that is about 5% ISO more than the Pars commercial bleached paper. Paper strengths were similar to Pars commercial paper made of soda bagasse and the national standard of Iran (ISIRI 4120). Soda pulp bleaching using O1QP3D(EP) sequence has led to acceptable physical, optical and mechanical properties in addition to environmental benefits such as reduce pollution. So, it is recommended to replace the current bleaching method of Pars paper mill by the mentioned sequence.
Mohammad Ali Hossein; Mohammad Talaeipoor; Amir Hooman Hemmasi; behzad baziyar; Saeed Mahdavi
Abstract
The effect of applying the sequence of enzymatic treatment and refining was investigated on the properties of deinked pulp from mixed office waste paper (MOW). Refining was applied for 700 and 1500 revolutions. Enzymatic treatment was applied for 60 minutes with temperature of 60°C and 13% of consistency. ...
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The effect of applying the sequence of enzymatic treatment and refining was investigated on the properties of deinked pulp from mixed office waste paper (MOW). Refining was applied for 700 and 1500 revolutions. Enzymatic treatment was applied for 60 minutes with temperature of 60°C and 13% of consistency. Applying enzymatic treatment led to decrease in strength properties of paper and also decrease in freeness of the pulp. The refining process resulted in increase of paper properties and decrease in freeness of the pulp. By applying enzymatic treatment before refining, the freeness of pulp changed significantly so that, the freeness of the pulp was 496 and 390 for 700 and 1500 refining revolution respectively just for refining but these numbers changed to 397 and 544 for same revolutions for “enzymatic treatment + refining” sequence. In a normal condition increase of refining revolution lead to decrease in pulp freeness but that was interestingly the freeness increased for 1500 refining revolution. This means that the enzymatic treatment was effective. Generally, refining itself improved the quality parameters of pulp and paper, but applying this process after enzymatic treatment changed everything.
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.
Physics and Mechanical Wood
Saeed Mahdavi
Abstract
The use of renewable energies, such as biomass, is becoming increasingly important as countries realize that bioenergy present an approach to their international commitments to reduce greenhouse gas emissions. Biomass with higher thermal energy value and optimal composition is more desirable for the ...
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The use of renewable energies, such as biomass, is becoming increasingly important as countries realize that bioenergy present an approach to their international commitments to reduce greenhouse gas emissions. Biomass with higher thermal energy value and optimal composition is more desirable for the thermal conversion systems. In present investigation, properties of ten type's wood biomass relevant to combustion were evaluated. Important characteristics requiring analysis for the biomass were moisture and ash content, volatile matter, elemental composition (C, H, N, S, and O), and high and low heating values (HHV and LHV). The heating value has been determined based on experimental and computational methods by colorimeter bomb and elemental content, respectively. The results showed that eldarica pine biomass had the highest content of biomass sulfur, which is undesirable environmental factor in the bioenergy system. Regarding to the fixed carbon to volatile matter ratio, Citrus sinensis var. thomson has the lowest ratio, so it is the best biomass for the gasification process. The highest and lowest heating values were determined for the poplar pruning residues (group a) and apple (group b and c), respectively. The highest and lowest of HHV and LHV were measured for P. deltoides and Malus spp., respectively.
Composite wood products
masoudreza habibi; Ahmad Jahan Latibari; Saeed Mahdavi
Abstract
This study was carried out to investigate the effect of storage time and moisture content of bagasse on the physical and mechanical properties of particleboard. For this purpose, wet depitting bagasse was used and samples were maintained in bailing storage method. In this study, was applied 4 storage ...
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This study was carried out to investigate the effect of storage time and moisture content of bagasse on the physical and mechanical properties of particleboard. For this purpose, wet depitting bagasse was used and samples were maintained in bailing storage method. In this study, was applied 4 storage times (1.5, 3, 4.5 and 6 months) and 2 moisture content of Bagasse (45% and 55%). According to these variables, particleboards were made. Also chemical properties (pH, acid and alkaline buffering capacity) of Bagasse were determined. The mechanical and physical properties of the boards were measured and statistically analyzed using factorial experiment and complete randomized design. Then Duncan multiple range test was used for grouping of the averages. The results revealed that with decreasing of Bagasse moisture content, Bagasse sample pH and acid buffering capacity were decreased and increased, respectively. Also bending properties and thickness swelling after 24 hours immersion of the boards were improved. With increasing of storage time, the chemical properties of Bagasse tend to be alkaline, and the minimum of board internal bond strength was obtained in 1.5 month storage time. The physical properties of boards were improved with increasing of storage time
Pulp and paper
Mohammad Mahdi Barazandeh; Saeid Mahdavi; Abbas Fakhryan
Abstract
Because of importance and wide usage of different species of Populus wood in paper pulping, the delignification reaction in pulping process of P. deltoides was investigated in order to obtain the relation between residual lignin in the pulp and cooking time. The samples were 10 years olded of Populus ...
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Because of importance and wide usage of different species of Populus wood in paper pulping, the delignification reaction in pulping process of P. deltoides was investigated in order to obtain the relation between residual lignin in the pulp and cooking time. The samples were 10 years olded of Populus deltoids woods which were collected from Chamestan Research Station located in Noor city of Mazandaran province. Kraft method was used for pulping the condition of which were 25% sulfidity, 14% alkali, 5:1 the ratio of liquor to sample, maximum cooking temperature as 155, 165, 175 degree centigrade. Kappa number and the yields of pulps were estimated and residual lignin was calculated for each sample. Using the models predicted for rate equation and trial and error method in excell software, the order and rate constant of delignification reaction were evaluated for each cooking temperature. The results show that the rate equations of delignification reaction of Populus deltoides in temperatures of 155°C, 165°C and 175°C have the orders of 5.5, 2.5 , 1 and the rate constants of 1.8× 10-7 min.-1 conc.-4.5, 7.7× 10-4 min.-1 conc.-1.5 and 3.5× 10-3 min.-1 , respectively. Using these equations it will be possible to control the pulping process and predict the time required to obtain a desired lignin concentration in the pulp.
Pulp and paper
Mohtaba Goli; Majid Zabihzadeh; Saeed Mahdavi; Hassan Sadeghifar
Abstract
The objective of this study was determination of the best method of bleaching including refining and bleaching (RB) or bleaching and then refining (BR) on chemical mechanical pulp (CMP) for the production of newsprint. Wood raw material consists of mixed wood forest species was chipped and air dried ...
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The objective of this study was determination of the best method of bleaching including refining and bleaching (RB) or bleaching and then refining (BR) on chemical mechanical pulp (CMP) for the production of newsprint. Wood raw material consists of mixed wood forest species was chipped and air dried to calculate the moisture content. Wood composition percentages for CMP pulping was 40% poplar, 30% maple, 7.5% oak, 7.5% alder, 7.5% willow, and 7.5% Persimmon. In order to remove heavy metal ions of pulp, the chelating was carried out with DTPA. TCF Bleaching carried out by 3% H2O2 and 2.5% NaOH based on dry weight of pulp with initial brightness of 44.6% ISO. Pulp bleaching was done in two stages, before and after the refining by laboratory PFI mill beater. Finally, handsheets were made from the RB and BR treated pulps and the sheet properties were evaluated according to TAPPI test methods. The results showed that BR treatment increased tensile, burst, tear indices, brightness, scattering coefficient, and density, but reduced yellowing, opacity, and light absorption coefficient. The results confirmed the conventional method of CMP pulp treatment (BR) in MWPI.
Chemical conversion
Fatemeh Jadidyan; Mohammad Talaeipoor; Saeed Mahdavi; Amirhoman Hamasi
Abstract
The purpose of this study is the evaluation of bagasse pith for heating energy and activated carbon production. To assess the energy production of the pith, bulk density, melting point, and heating value were measured. Furthermore, percentage of moisture, ash, volatile compounds, fixed carbon, lignin, ...
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The purpose of this study is the evaluation of bagasse pith for heating energy and activated carbon production. To assess the energy production of the pith, bulk density, melting point, and heating value were measured. Furthermore, percentage of moisture, ash, volatile compounds, fixed carbon, lignin, and elements contents were determined. Ash and volatile content average were measured at 30.23% and 67.14%, respectively. The bulk density average of the pith powder with 80 meshes was determined at 0.15 g/cm3. Lignin content and melting point of pith is measured 23.1%, and 1050 °C, respectively. Sulfur content is important in terms of environmental pollution and it was determined 0.3%. Gross heating value was measured directly by calorimeter bomb to 10.30 MJ/kg that is lower than bagasse and wood. The activated carbon produced from pyrolysis of bagasse pith was chemically activated with zinc chloride. The chemically activated carbons were characterized by measuring iodine of 504 mg/g, specific surface (BET) of 478 m2/g, and pore diameter of 7.45 nanometer. It is suitable for liquid absorption according to the pore size.
Pulp and paper
Saleh Ghahrmani; Sahab Hejazi; Saeid Mahdavi
Abstract
In this research, capacity of cellulose nanofibers to reinforce of high yield kraft pulp produced (HYKP) from Populus deltoides clone 69-55 for making unbleached top kraft liner (UTKL) was investigated. The variable conditions of cooking were included the cooking time and temperature each one in two ...
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In this research, capacity of cellulose nanofibers to reinforce of high yield kraft pulp produced (HYKP) from Populus deltoides clone 69-55 for making unbleached top kraft liner (UTKL) was investigated. The variable conditions of cooking were included the cooking time and temperature each one in two levels. Sulfidity and active alkali were constant in the all cooking and liquid to wood ratio was 4 to 1. Optimum pulp was selected according to the pulp yield and kappa no. to reinforce by cellulose nanofiber. Then, it was refined by PFI mill beater to achieve 385 ml. CSF. The cellulose nanofiber was added in three levels (5, 10 and 15%) to HYKP, then mixed for 5 min. and handsheet made by special wire. The result indicated that 15% adding of cellulose nanofiber to high yield kraft pulp increased tensile index by 39%, burst index by 33%, tear index by 17.7%, bending stiffness index by 38% and ring crush tests (RCT) by 55.47%, respecting to the HYKP. In overall, it is recommended nanofiber adding to HYKP for UTKL making according to the yield and also physical and strength of reinforced pulp.
Pulp and paper
mojtaba goli; Ghasem Asadpur; Saeed Mahdavi; Abdollah Barimani
Abstract
Importing of wood is a solution to supplying raw material in the Iranian paper industry because of wood shortage. Therefore, the effect of mixing the imported aspen roundwood with the two hardwood native forest species including hornbeam and beech were perused on the optical and mechanical properties ...
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Importing of wood is a solution to supplying raw material in the Iranian paper industry because of wood shortage. Therefore, the effect of mixing the imported aspen roundwood with the two hardwood native forest species including hornbeam and beech were perused on the optical and mechanical properties of CMP pulp. Cooking constant conditions consist of maximum temperature were 170 °C with a liquor-to-wood ratio (L/W) of 7, and chemical content of 20% based on the oven-dry weight of the wood chips. CMP pulps were prepared at different cooking times of 30 to 120 minutes using 20, 30, 40, 60, and 100% aspen wood in combination with the two species to achieve the yield of nearly 85%. Standard laboratory handsheets were made after pulp refining by 300 ml CSF, and then the strengths and optical properties were measured. Statistical analysis of result showed that there were significant differences among of the properties of CMP pulps by increasing the aspen wood ratio. All the properties have been improved except opacity paper. The required strength of newsprint and printing/writing paper made in Mazandaran wood and paper industries (MWPI) could be achieved by mixing of 20 and 30% imported aspen wood to the native species used in currently, respectively.
Composite wood products
Hossein Ahmadi; Amir hooman hemmasi; Saeed Mahdavi
Abstract
The aim of this study is investigating the mechanical properties of recycled HDPE (high-density polyethylene) filled by furfural residue produced from bagasse. For this purpose, rHDPE was used at three levels 58, 68 and 78% and furfural residue as a filler was added at levels of 20, 30 and 40%. The grafted ...
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The aim of this study is investigating the mechanical properties of recycled HDPE (high-density polyethylene) filled by furfural residue produced from bagasse. For this purpose, rHDPE was used at three levels 58, 68 and 78% and furfural residue as a filler was added at levels of 20, 30 and 40%. The grafted maleic anhydride with polyethylene (PE-g-MA) was used at constant amount of 2% as compatibilizer which prepared from Arya polymer Co. The ingredients mixed in two screw extruder and test samples were made using injection molding method. Composite properties such as tensile strength, flexural and V-notch impact were measured according to ASTM standards. The results showed that with increasing the filler content of 20 and 30% by weight, tensile modulus and flexural strength increased compared to the control and then reduced by 40 percent of filler. FTIR spectroscopy of the furfural residue and composite filled by 30% was carried out. Also, by increasing the filler content of 20 to 40% by weight, V-notch impact strength of composite decreased. FTIR spectroscopy revealed that the absorption bands of carbonyl groups (C=O) in 1750-1600 cm-1 wavelength has slightly increased in the present of maleic anhydride compatibilizer which resulted maximum increasing of mechanical properties of composite using 30% residual furfural.
Pulp and paper
Afshin Veisi; Saeed Mahdavi; Mohammad Talaeipoor
Abstract
In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals ...
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In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals charge and 10:1 cooking liquor and straw ratio. The yield after defibration treatment varied between 56.5% and 72.5%. Two optimum pulps bleached by TCF method applying 2% and 3% NaOH, 1.5% and 2% H2O2, and 60 and 120 minutes bleaching time. One way analysis variance method showed that bleaching time had the most significant effect on optical properties of handsheet. Applying 3% (based on oven dry weight of the unbleached pulp) NaOH, 2% H2O2, and 120 min. in bleaching improved the brightness and opacity to 52.9%, and 79.5% ISO, respectively. Optimum pulp strengths including tensile, burst and tear indices were measured 43.87 Nm/g, 2.18 kPa.m2/g, and 8.46 mN.m2/g, respectively. All the strengths were higher than newsprint paper strength produced by Mazandaran wood and paper and Korean companies.
Pulp and paper
farzaneh shiralizadeh; mohammad azadfallah; ali Abdolkhani; mohammad Layeghi; saeed mahdavi
Abstract
This study was conducted with the aim of producing laboratory samples of transparent paper using overbeating method. Hence, bagasse bleached soda pulp was subjected to post-bleaching sequence of DED to remove residual chromophores. Then this pulp was refined in a PFI mill to reach different ...
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This study was conducted with the aim of producing laboratory samples of transparent paper using overbeating method. Hence, bagasse bleached soda pulp was subjected to post-bleaching sequence of DED to remove residual chromophores. Then this pulp was refined in a PFI mill to reach different levels of 55, 130, 200, and 260 mL,CSF (Canadian standard freeness) freeness. Then handsheets were made according to TAPPI standard T 205 om– 8. Results indicated that refining has significant effect on optical properties especially transparency so that the maximum value was observed using pulp with the minimum freeness, i.e. 55 ml. The variations of transparency due to refining were also further explained by measuring scattering coefficient, opacity and brightness of the specimens. In addition, mercury porosimetry and analyzing the pictures of scanning electron microscopy (SEM) demonstrated the extensive variations of pore structure in paper during refining which impose great influence on developing transparency.
Saeid Mahdavi; Masoudreza Habibi
Abstract
Cereal straws including grain sorghum varieties can be used for pulp production due to the significant amount of residual straw after harvesting. This study showed that there are no significant differences between fiber dimension and papermaking coefficients of two varieties of sorghum (Kimia and Sepideh). ...
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Cereal straws including grain sorghum varieties can be used for pulp production due to the significant amount of residual straw after harvesting. This study showed that there are no significant differences between fiber dimension and papermaking coefficients of two varieties of sorghum (Kimia and Sepideh). The average of fiber length, fiber width, lumen diameter, and cell wall thickness were measured as 1.19 mm, 23.20, 15.34, and 3.93 µm, respectively. Significant difference (P < 0.05) was found among all chemical composition of two varieties except lignin content. The average content of holocellulose, alpha-cellulose, lignin, extractive, and ash were determined as 62.13%, 37.71%, 21.05%, 9.58% and 6.97%, respectively. The result revealed that pulp strength produced from Sepideh variety was better. However it requires more intense delignification compared to Kimia variety. The highest screen yield (33.19%) was reached applying the treatment combination of 170°C, 12% NaOH, and 75 minutes from the Sepideh variety. Sorghum pulp could be combined with the virgin pulp to compensate cellulose raw material shortage in paper industry.
Pulp and paper
Hadi Hasanjanzadeh; sahab hejazi; saeed mahdavi
Abstract
In this study, rice straw as an abundant and cheap raw material selected to produce soda - anthraquinone pulp. Nano fiber Cellulose of rice straw were added to improve the pulp strength after cationing. Cationed suspension was mixed at three levels including 2, 5 and 10 percent with nano fiber cellulose. ...
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In this study, rice straw as an abundant and cheap raw material selected to produce soda - anthraquinone pulp. Nano fiber Cellulose of rice straw were added to improve the pulp strength after cationing. Cationed suspension was mixed at three levels including 2, 5 and 10 percent with nano fiber cellulose. Starch and polyacrylamide as cationic chemicals were used to stabilize nano fiber cellulose at 1.5% and 0.2% based on oven dried pulp, respectively. The result showed that there is linear change between stock drainage time and paper strength according to nano fiber cellulose added content. Tensile and burst index were improved at 18.66% and 18.12% respectively by adding 10% of nano fiber cellulose to suspension treated with cationic polyacrylamide. Furthermore, the two indices increased until 19.35% and 19.24% by adding of maximum amount of nano fiber cellulose (10%) to cationed pulp suspension with cationic starch, respectively. The use of nano fiber cellulose had a positive significant effect on paper properties.
Saeid Mahdavi; Masoud reza Habibi
Abstract
Paper industry has been experiencing growing shortage of cellulosic material over the last decades. As a fast-growing plant, kenaf has good potential to compensate wood shortages taking into account its long historical record of cultivation in Iran. Kenaf variety of 432 was collected from Varamin ...
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Paper industry has been experiencing growing shortage of cellulosic material over the last decades. As a fast-growing plant, kenaf has good potential to compensate wood shortages taking into account its long historical record of cultivation in Iran. Kenaf variety of 432 was collected from Varamin research station. Kenaf stalk yield was determined roughly as 10.5 air-dried metric tonnes (ADMT) per hectare for a single crop rotation. Soda pulping of core, bast and their mixture were carried out at three weight percent ratios of 50:50, 40:60 and 30:70. H-factor for the delignification process was adjusted about 800 using cooking treatment combination of 175 °C, 30 min, 18% sodium hydroxide, and 5:1 liquor to raw material ratio. Under similar cooking condition, yield and kappa no. of soda pulp prepared from the mixture of kenaf core and bast showed highest yield and kappa number. Kappa no. decreased with increasing bast fiber percent from 50% to 70%, and required increased PFI revolution to achieve certain freeness. Handsheet properties including thickness, breaking length, burst and specially tear index increased at higher bast fiber content.
Negin Nikbin; Saeid Mahdavi; Hossein Kermanian; Omid Ramezani; Amir Mohssen Nazeri
Abstract
Native starch has relatively suitable characteristics including biodegradable properties, being widely used as an adhesive in the corrugated carton manufacturing companies. Corn starch is currently used in the companies for producing adhesives. In this study, fines of NSSC pulp as natural additive and ...
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Native starch has relatively suitable characteristics including biodegradable properties, being widely used as an adhesive in the corrugated carton manufacturing companies. Corn starch is currently used in the companies for producing adhesives. In this study, fines of NSSC pulp as natural additive and ammonium persulfate as chemical oxidative additive were used to improve the adhesion properties of corn starch. Fine was added at three levels of 5%, 10%, and 15% (based on oven-dry weight of starch) and ammonium persulfate similarly was mixed at 5 levels of 0.1, 0.2, 0.3, 0.4 and 0.5 grams. Addition of fine was lead to increasing adhesion strength (PAT) of the corrugating board to the amount of 25%, 35% and 43% respectively. This improvement could be due to increasing the number and strength of hydrogen bonding of fiber layers (corrugating and liner paper) and value of solid content. Addition of ammonium persulfate revealed that the method applied similar to mixing fine had no desirable results and the other methods should be used.
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.
Mohammad amin Andalibian; Saeid Mahdavi; Hossein Kermanian; Omid Ramezani
Abstract
The possibility to improve the test liner board properties using mechanical treatments (refining) was studied. Old Corrugated Container (OCC) fibers used in a recycled paper manufacturing company were quantitatively and qualitatively analyzed and hardwood and softwood fibers content were estimated as ...
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The possibility to improve the test liner board properties using mechanical treatments (refining) was studied. Old Corrugated Container (OCC) fibers used in a recycled paper manufacturing company were quantitatively and qualitatively analyzed and hardwood and softwood fibers content were estimated as 22.6% and 60%, respectively. The mechanical treatment of pulp fiber was performed in a Valley Beater until the target freeness of 400 ml CSF. Then hand sheets with the basis weight of 127 g/m2 were made and the apparent density, Gurley air resistance, burst strength, folding endurance, Elmendorf tear strength, tensile strength and RCT were measured according to TAPPI standards. The results showed that all the properties of the refined sample increased compared to the control sample. Comparing the strength properties of the paper produced from refined pulp with the relevant values in Iranian national standards indicated the 33%, 50%, 117% increase in burst index, tensile index, and tear index, respectively. The refined pulp RCT strength increased by 28% compared to that of control sample. As the results indicated, test liner boards with suitable strength can be manufactured locally and even exported.
Pulp and paper
Ahmad Samariha; Jafar Ebrahimpoor kasmani; Saeed Mahdavi
Abstract
Rapeseed straw was collected from a cultivation farm in the vicinity of Babul, Mazandaran. Average fiber length, width, lumen diameter and cell wall thickness were measured as 860, 27.95, 18.86, and 4.42 µm respectively. Chemical components of rapeseed straw including cellulose, lignin, ash and ...
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Rapeseed straw was collected from a cultivation farm in the vicinity of Babul, Mazandaran. Average fiber length, width, lumen diameter and cell wall thickness were measured as 860, 27.95, 18.86, and 4.42 µm respectively. Chemical components of rapeseed straw including cellulose, lignin, ash and extractives were measured as 44%, 19.21%, 6%, and 13% respectively. Optimum pulping conditions to reach the pulp yield of 66%, were selected applying chemical charge of 20% (based on Na2O), cooking temperature of 170 ºC, and cooking time of 30 min. The pulps were refined to 350 and 400 ml CSF using PFI mill. Statistical analysis showed that mechanical properties of hand sheets with the basis weight of 127 g m-2 made from rapeseed straw NSSC pulp at the freeness of 350 and 400 ml CSF exhibited better properties compared to mixed hardwood NSSC pulp to produce fluting paper.
