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.
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.
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%.
Pulp and paper
Iman Akbarpoor; Hossein Resalti; Ahmad reza Saraeyan
Abstract
In this study, Deinking of old newspaper was investigated by chemical and enzymatic methods. Chemical treatment was done using chemicals at different times of 10, 20 and 30 minutes, consistency of 10%, temperature of 50±1!C along with washing, flotation and combination of washing/flotation. While, ...
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In this study, Deinking of old newspaper was investigated by chemical and enzymatic methods. Chemical treatment was done using chemicals at different times of 10, 20 and 30 minutes, consistency of 10%, temperature of 50±1!C along with washing, flotation and combination of washing/flotation. While, Enzymatic treatment was accomplished at different concentrations of 0.025, 0.05, 0.1 and 0.2% of cellulase enzyme (on the basis of oven dried waste paper), pH range of 5-5.5, different times of 10,15 and 20 minutes, consistency of 10%, temperature of 50±1!C along with washing. The results comparison of optimum chemical and enzymatic treatments showed that, deinked pulp by chemical method had higher brightness and yellowness. Also, deinked pulp by chemical method resulted the papers with higher bulk, higher caliper and higher air resistance.
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.
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.
Pulp and paper
Jalil Roshanasan; Mohammadreza Dehghani firozabadi; Mohammad Dahmardeh ghaleh no; Saeideh Sharifi
Abstract
The lignin dissolution in Kraft pulping for wheat straw was studied. Kraft pulping was carried out under the conditions: chemical charge of 18% (as NaOH, based on o.d. bagasse), sulfidity of 25% and liquor to wheat straw ratio of 10:1. Six cooking maximum temperatures of 85,100,110,120,130 and 150 ◦C, ...
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The lignin dissolution in Kraft pulping for wheat straw was studied. Kraft pulping was carried out under the conditions: chemical charge of 18% (as NaOH, based on o.d. bagasse), sulfidity of 25% and liquor to wheat straw ratio of 10:1. Six cooking maximum temperatures of 85,100,110,120,130 and 150 ◦C, were selected and reaction time varied from 0 to 250 min. based on maximum temperature. The Klason lignin, acid soluble lignin, ash and extractive contents of wheat straw were 18.4%, 2.07%, 3.24% and 4.56 respectively.
During alkaline pulping of wheat straw, about 64% and 52% of lignin was removed before reaching to the temperature 100 ◦C and 85 respectively. The values pulp and carbohydrates yield were, about 64%, 58% for 85 ◦C and 61%, 57% for 100◦C.
Pulp and paper
Jafar Ebrahimpoor kasmani; Amir mohssen Nazeri; Ali Ashryeh
Abstract
In this investigation , effects of different humidity and heat on quality of Corrugated board , was studied , and optimum treatment indicated Variables in this Paper was : Corrugator speed (50,100,150m/min) ,wraping angle of the paper around preheaters ...
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In this investigation , effects of different humidity and heat on quality of Corrugated board , was studied , and optimum treatment indicated Variables in this Paper was : Corrugator speed (50,100,150m/min) ,wraping angle of the paper around preheaters (90,180,300 degree) and moisture of paper (6.5%,7%,8.5%). Papers that treated for this purpose was included : 125gsm kraft liner ,127 gsm medium paper and 140gsm test liner paper. A flut type of 3ply Corugated board was selected for this study.Moisture of paper was measured in 3 places : Paper on roll stand before single facer , paper after singlefacer preheater and paper before incoming doublefacer in hot plate unit. Also temprature was measured in corrugator rolls ,hot Plates in double facer and final Board after Exiting of the Machine.
Results show that , warp of final board decreased in speed 50 and 100m/min ,moisture 7% and 1800 wraping angle of the paper around preheater.
That means lower speeds and higher wraping angles cause to more heat on corrugated board and decreasing in warp content resulted.It should be noted that lower humidity more than 7% and increase wraping angle more than 180 degree cause to over drying and intensive moisture decrease in final board that cause to reverse warp in final board.
Pulp and paper
fatemeh rajabi; seyed majid zabizadeh
Abstract
The objective of this study was the evaluation of optical, mechanical properties of chemi-mechanical pulp which were bleached by one and two stage bleaching sequence of hydrogen peroxide and sodium hypochlorite. Also the environmental effects of effluents from bleached paper liquor were studied. For ...
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The objective of this study was the evaluation of optical, mechanical properties of chemi-mechanical pulp which were bleached by one and two stage bleaching sequence of hydrogen peroxide and sodium hypochlorite. Also the environmental effects of effluents from bleached paper liquor were studied. For this purpose, unbleached CMP pulp mixed of hardwoods was prepared from Mazandaran Wood and Paper mill. Then, these pulps were bleached using P (hydrogen peroxide), H (Sodium Hypochlorite), PH (Hydrogen Peroxide and Sodium Hypochlorite) and HP (Sodium Hypochlorite and hydrogen peroxide) stages. 60 gr/m2 hand sheets were prepared and the optical, mechanical properties of hand sheets and also their effluent bleaching liquor characteristics were measured and analyzed based on TAPPI and APHA Standards. The results showed that when peroxide was applied at the last stage of bleaching, then the properties such as tear, tensile and brightness have increased and yellowness has decreased. Generally, the role of single sequence of bleaching by P and two sequence of bleaching with HP were more effective than single sequence of H or unbleached pulp. Based on results, the highest and lowest COD load is related to bleaching liquor of H and PH respectively. Moreover, bleaching liquor of hydrogen peroxide had the highest BOD load and the lowest amount of BOD is related to PH sequence of bleaching.
Pulp and paper
Jafar Azizi; Omid ramezani; Esmaeel Rasooly; Hamidreza Rudi
Abstract
Cellulosic fines are essential parts of paper making system which impart remarkable effects on the production process parameters and the quality of final product. In this study, properties of fiberfines prepared from three kinds of pulps including Kraft, chemical mechanical (CMP), and recycled (OCC) ...
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Cellulosic fines are essential parts of paper making system which impart remarkable effects on the production process parameters and the quality of final product. In this study, properties of fiberfines prepared from three kinds of pulps including Kraft, chemical mechanical (CMP), and recycled (OCC) were investigated. Required amounts of fines were prepared using Valley Beater apparatus. Then the fines were classified into three categories using dynamic drainage Jar (DDJ): fines passing a 100 mesh remained on 200 mesh (P100/R200), fines passing a 200 mesh remained on a 325 mesh (P200/R325), and fines passing a 325 mesh (P325). Fines properties including dimensional size, special hydrodynamic volume, colloidal charge, alkalinity, turbidity, viscosity, and specific area were examined. The results revealed that PH of fiber suspensions tended alkaline concurrently to the decreasing in dimensional size of fines. Additionally, the colloidal charge of the three types of fines, especially the charge associated with the fines passed through 200 mesh screen and remained on 325 mesh one, showed a different behaviour compared to those in the same classes with the adverse trend to the viscosity variation. Special hydrodynamic volume is consistent with the dimensional size and dimensional ratio with the lowest amount of it observed in the recycled pulp fines. Turbidity has a direct relationship with particles size, homogenous distribution and the specific area of the finesThe results of turbidity related to the fines passed through 200 mesh size showed different behaviour compared to other categories.
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.
Pulp and paper
Hossein Resalati; Mostafa Nikkhah Dafchahi
Abstract
One of the drawbacks of utilizing non-forest fast growing species of Poplar as raw materials to produce newsprint in Mazandran Pulp and Paper Mill is fairly low bulk and opacity of produced paper at the yield of 85% (current CMP yield of the Mill). In this research work, the effect of process parameters ...
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One of the drawbacks of utilizing non-forest fast growing species of Poplar as raw materials to produce newsprint in Mazandran Pulp and Paper Mill is fairly low bulk and opacity of produced paper at the yield of 85% (current CMP yield of the Mill). In this research work, the effect of process parameters (cooking yield and freeness) on the optical and mechanical properties of chemi-mechanical pulp was investigated. The chemi-mechanical pulps of poplar was prepared at four various levels of cooking yield, through changing the cooking time, and their properties at different level of freeness were evaluated in comparison with the control sample of Mazandran Pulp and Paper Mill (75% hornbeam and 25% beech). Strength properties of the paper pulps stemmed from the cooking yields of 85.25% to 90.4% were higher and more favorable than the control sample. By contrast, the strength properties of the produced paper pulp from the cooking yield of 94.6% were inferior to prepared paper pulp from the control sample. According to the results, there is the possibility of significant improvement of the strength properties, opacity and bulk of the chemi-mechanical pulps of poplar trough controlling the process parameters like cooking yield and freeness to utilize it as raw material of newsprint production in Mazandran Pulp and Paper Mill.
Pulp and paper
Hamid reza Rodi; Ali Soleymanisadati; Hosein Jalalitorshizi
Abstract
In this research, the effect of adding precipitated calcium carbonate filler combined with nanocellulose as reinforcement was examined to compensate the strengths loss of papers made of bagasse pulp. About 2 % of nanocellulose based on oven dry fibers suspended in water with 0.1 % consistency homogenized ...
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In this research, the effect of adding precipitated calcium carbonate filler combined with nanocellulose as reinforcement was examined to compensate the strengths loss of papers made of bagasse pulp. About 2 % of nanocellulose based on oven dry fibers suspended in water with 0.1 % consistency homogenized by ultrasonic was added to the pulp having 15 % PCC filler and was compared with the same sample without nanocellulose and base pulp (without any additives). Cationic polyacrylamide retention agent was added to the pulp suspension at the constant level of 0.14 % based on oven dry fibers. Statistical analysis of results revealed that the drainage time increased by adding of PCC and nanocellulose system to the bagasse pulp suspension. Addition of nanocellulose has enlarged filler particle retention due to the formation of adhesive flocs. Prepared SEM images from paper samples confirm filler particles flocculation, larger filler retention and their better distribution in paper network. Moreover, in papers filled by PCC and nanocellulose with roughly equal similar opacity and brightness, loss of strength characteristics due to adding of filler has been compensated. Although relatively higher drainage time of this pulp suspension is a substantial limitation, but pretreatment of filler with nanocellulose prior to its addition to the pulp can be investigated as a promising alternative.
Pulp and paper
Hamid reza Rodi; Haseibeh Saeedi; Kermanian Hossein
Abstract
Improvement the strength properties of papers made from recycled fibers is of important aims in papermaking industries. Current researches revealed that higher retention of strength induced additives through alternative absorption of polymers having opposite charge is one of promising approaches to obtain ...
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Improvement the strength properties of papers made from recycled fibers is of important aims in papermaking industries. Current researches revealed that higher retention of strength induced additives through alternative absorption of polymers having opposite charge is one of promising approaches to obtain such purpose. In this study, treatment of fibers prepared from neutral sulfite semi-chemical papers with cationic starch and anionic CMC was conducted in pH~7, pH~10 and 0.001 M NaCl salty suspension. Then, fibers water retention value and zeta potential was measured. Standard handsheets with 60±3 g/m2 basis weight were made from untreated and treated pulps. The results have shown that fibers WRV significantly increased by absorbing of these two water-loving polymers. Consecutive changes of zeta potential confirmed charge reversion of fibers surface and sequential absorption of couple polymers. Scanning electron micrographs prepared from the samples of untreated and treated papers presented new variations in amount of fibers bend area due to the larger absorption of these two reinforcement polymers. Moreover, considerable development in paper mechanical characteristics (tensile, burst and tear indices) proved the success of high absorption of applied bio-polymers.
Pulp and paper
Mojtaba Goli; Saeed Mahdavi
Abstract
Abstract In recent years, environmental problems of irregular wood harvesting and shortages of raw materials made wood and paper Ind. & country to be faced serious crises. And some researchers and industry experts have led to fundamental and long-term solution for supplying raw materials to these ...
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Abstract In recent years, environmental problems of irregular wood harvesting and shortages of raw materials made wood and paper Ind. & country to be faced serious crises. And some researchers and industry experts have led to fundamental and long-term solution for supplying raw materials to these industries. This present study aimed to determine the optimum conditions of pulping and bleaching for several hardwood forest species (as a separate cooking & Combining with 40% popular, 15% beech and hornbeam 45%) and paper evaluation. After preparing CMP in accordance with the terms of an 85% efficiency , Different cooking times (25-60 minutes, temperature of 170 °C, the ratio of L TO W & 7 TO 1 and Making hand sheet with standard 60 gram per square meter, Optical and mechanical properties of paper was evaluated. The results showed that, A species that was used in cooking, Poplar were better in terms of total properties with mechanical and optical properties. Also in Bleaching stage, the tensile strength index is decreased & Burst and tear strength index is improved. The maximum brightness is related to poplar species with mixing and without species and after bleaching the beech is the lowest ones. In both methods the rate of opacity and yellowness is decreased.
Pulp and paper
Alireza Sukhtesaraie; Mohammad Azadfallah; Saeed Bastani
Abstract
Flexographic printing is the most usable technology in the packaging industry. But the lack of proper adhesion of water-based ink on cardboard coated with polyethylene is one of the most important problems. Silane adhesion promoters are considered among the best compounds used as the crosslinking and ...
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Flexographic printing is the most usable technology in the packaging industry. But the lack of proper adhesion of water-based ink on cardboard coated with polyethylene is one of the most important problems. Silane adhesion promoters are considered among the best compounds used as the crosslinking and waterproofing agents in coating and ink industries. In this study, N-(2-Aminoethyl) (3-aminopropyl) methyldimethoxysilane and 2-(3, 4-Epoxycyclohexyl) ethyltriethoxysilane were used to improve the adhesion of water-based ink on paper boarded-coated with polyethylene. Results showed that highest amount of adhesion were achieved by adding 5% of N-(2-Aminoethyl) (3-aminopropyl) methyldimethoxysilane to ink. Adding silane compounds to ink formulation increased the contact angle of the ink film on the surface of cardboard coated with polyethylene which means that inks containing silane compounds act more successful in the formation of hydrophobic surface. It is worth noting that surface tension was decreased by addition of silane components to the formulation of the ink.
Pulp and paper
Ramin Vaysi; Ali reza Bagheri
Abstract
The objective of this research was accomplished on the effects of total chlorine free (TCF) and elemental chlorine free (ECF) bleaching on optical and mechanical properties of bagasse soda pulps. For this purpose, some unbleached bagasse soda pulps were randomly selected from Ahvaz Pars industry. Then ...
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The objective of this research was accomplished on the effects of total chlorine free (TCF) and elemental chlorine free (ECF) bleaching on optical and mechanical properties of bagasse soda pulps. For this purpose, some unbleached bagasse soda pulps were randomly selected from Ahvaz Pars industry. Then these pulps were bleached with one, two and three P, OP, OPY, O(Ep)P, EHP and O(Ep)H bleaching stages by using oxygen(O) hydrogen peroxide(P), alkali extraction with hydrogen peroxide(Ep), sodium hypochlorite(H) and sodium dithionite(Y). The hand sheets with 70 gr/m2 were prepared from above-mentioned of pulps, and then the optical and mechanical properties were measured and compared according by using TAPPI standard test methods. The results showed that brightness, greenness, tear (except EHP stages), tensile, burst, breaking length strengths and folds were increased and opacity and a* factor were decreased by ECF and TCF bleaching stages. The effects of TCF bleaching stages were more sensible than ECF bleaching stages in improve of bagasse soda properties, too. In general, role of three OPY and O(Ep)H stages and two OP bleaching stages were better than EH(control) stage and unbleached bagasse soda pulps mill in improve of brightness and its paper strengths, too.
Pulp and paper
zahra takzare; kermanian hossein; omid ramezani; Esmaeil Rasooly Garmaroody; Ali Abdolkhani
Abstract
In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, ...
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In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, and in four times 15, 30, 60 and 90 minutes and rate of liquor to waste 7:1 in Soda process. Obtained Soda pulps were evaluated in yield, lignin percentage, water retention value (WRV), viscosity and crystallinity. Results showed that by prolonging of cooking time, pulp yield and lignin percentage were decreased and WRV increased. Also, pulp viscosity in 30, 45 min was increased by increasing in cooking time that according to other results, it seems that it is false viscosity. In addition, accordance with characterizing of samples by XRD, by progressive cooking time from 15 to 45 min, sample crystallinity decreased and in 60 min its value is increased. According to the pulps viscosity and downward trend of lignin removal with progressive cooking time, this addition can be due to crystallization of hemicellulose like xylan on the crystalline zone of cellulose chain. Therefore, according to the results and based on Bio-refinery concept, cooking time 30 min suggested as the best option for production of high value-added products in saccharification process.
Pulp and paper
Bagher Ashrafi Rad; Mohammad Azadfallah; Fatemeh Kolaei Moakhar; Soheila Izadyar; Mehdi Rahmaninia
Abstract
Utilization of paper as packaging material and developing applied technological program on paper-based substrate are drastically dependent to control of cellulosic fiber hydrophilicity and to enhancement of its hydrophobic properties. Then this work carried out with the aim of developing hydrophobic ...
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Utilization of paper as packaging material and developing applied technological program on paper-based substrate are drastically dependent to control of cellulosic fiber hydrophilicity and to enhancement of its hydrophobic properties. Then this work carried out with the aim of developing hydrophobic surface on cellulosic fiber with layer by layer (LBL) method while keeping and enhancing the properties of paper network. The deposition was implemented by titanium dioxide nanoparticles and poly acrylic acid as cationic and anionic layer respectively on the fibers of unbleached hardwood Kraft pulp and using Zycosil and fluoroalkyl silane on the last layer. The hand-sheets were then made by this modified fiber. The contact angle and roughness were measured to evaluate the effect of layers on hydrophobicity. The results indicated that roughness increased with the number of layers. The instant contact angle was also increased with the number of layers and reached approximately to 110 degree at 7th layer. The dynamic contact angles dropped more lately with increasing the number of layers. The fluorosilane deposition as 8th layer in comparison with Zycosil showed more effect on surface energy reduction. The instant contact angle of Zycosil treated paper was measured 125 degree which dropped significantly to 48 degree after 30 seconds. However, fluorosilane modified paper exhibited contact angle of 140 degree at the same time. In addition, the presence of titanium dioxide nanoparticles on the surface of fiber was demonstrated by scanning electron microscopy (SEM) of paper surface.
Pulp and paper
Hossein Resalati; Mostafa Nikkhah Dafchahi
Abstract
Due to shortage of harvestable forest wood in Iran, the potential of CMP pulp production from various species of salix (alba, fragilis and aegyptica), in comparison with populus deltoides, was investigated across this research work. The cooking liqour of Mazandaran wood and paper Mill, consisting of ...
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Due to shortage of harvestable forest wood in Iran, the potential of CMP pulp production from various species of salix (alba, fragilis and aegyptica), in comparison with populus deltoides, was investigated across this research work. The cooking liqour of Mazandaran wood and paper Mill, consisting of 50:50 ratios of sodium sulfite and sodium bisulfite, and hydrogen peroxide, were used for Chemical treatment and bleaching of the pulps, respectively. The results showed that the paper pulps of fragilis salix and alba salix had higher bulk and lower opacity than other species, respectively. From the strength properties point of view, the highest and lowest tensile strength of produced papers were related to alba and fragilis species, and, the highest and lowest burst and tear strength of the prepared papers have belonged to Salix aegyptica and Populus species, respectively. The data have shown that Salix species have a good pothential to be used as raw material to produce CMP pulp at the cooking yield of 85%. According to the results of this research work, alba salix and aegyptica salix are in first and the second priority to produce CMP pulp ,at the cooking yield of 85%, respectively.
Pulp and paper
Ramin Vaysi; Mohammad reza Salimifar
Abstract
This study and it aim was accomplished on the effect of TCF bleaching on optical and mechanical properties of CMP pulp. For this purpose, some unbleached CMP pulps were randomly selected from Mazandaran Wood and Paper Industries (MWPI). Then these pulps were bleached with two and three OP, OPY, PY and ...
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This study and it aim was accomplished on the effect of TCF bleaching on optical and mechanical properties of CMP pulp. For this purpose, some unbleached CMP pulps were randomly selected from Mazandaran Wood and Paper Industries (MWPI). Then these pulps were bleached with two and three OP, OPY, PY and O(Eo)P bleaching stages by using oxygen(O), alkali extraction with hydrogen peroxide(Eo), sodium dithionite(Y) . The hand sheets with 70 gr/m2 were prepared from above-mentioned of pulps, and then the optical and mechanical properties were measured and compared according by using TAPPI Standard test methods. The results showed that brightness, greenness, folds breaking length, tensile and tear strength were increased and opacity and a* factor were decreased. In general, role of three O(Eo)P stages and two OP and PY bleaching stages were better than P stage and unbleached CMP pulp mill in improve of brightness and its paper strength, too.
Pulp and paper
Hamid reza Rodi; Hossein Jalali Torshizi; Esmaeil Rasooly Garmaroudy
Abstract
The aim of this study was to investigate the effect of using different fillers in the presence of cationic rosin sizing agent on the properties of pulp and paper made from CMP fibers. For this purpose, cationic rosin internal sizing agent at the levels of 0, 0.5, 1 and 1.5 % based on oven dry fibers, ...
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The aim of this study was to investigate the effect of using different fillers in the presence of cationic rosin sizing agent on the properties of pulp and paper made from CMP fibers. For this purpose, cationic rosin internal sizing agent at the levels of 0, 0.5, 1 and 1.5 % based on oven dry fibers, and fillers including grounded carbonate calcium (GCC), precipitated carbonate calcium (PCC), Talc and Zeolite in 25 % level based on oven dry paper accompanied with cationic polyacrylamide retention agent at the constant level of 0.3 % based on oven dry fibers were added to the CMP pulp suspension according to the TAPPI standard. In order to examine the effect of different fillers in the presence of cationic rosin, handsheets with basis weight of about 60±3 g/m2 were prepared from each experiment. Then, various pulp and paper characteristics were measured. Statistical analysis of the results revealed that type of filler has dissimilar behavior on the pulp and paper properties in the presence of cationic rosin. Drainage time of pulp suspension was lower when adding Zeolite and GCC fillers. Talc and PCC decreased more the paper strengths properties. Ultimately optical properties of papers improved more when Talc and PCC were added to the CMP pulp. Consequently, with respect to the priority of brightness and opacity for the copy and print papers made from CMP fibers, addition of Talc and PCC in the presence of cationic rosin sizing agent may be meet more the requirements compare to Zeolite and GCC fillers.
Pulp and paper
Sobhan Jahanshahlou; Amir Khosravani; Mehdi Rahmaninia
Abstract
Production of test liner and fluting from old corrugated containers, is one of the most common paper recycling processes in Iran. This type of papers, have high basis weight and also contain significant fine fibrous and non-fibrous materials; hence, the drainage and in addition, the retention of fine ...
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Production of test liner and fluting from old corrugated containers, is one of the most common paper recycling processes in Iran. This type of papers, have high basis weight and also contain significant fine fibrous and non-fibrous materials; hence, the drainage and in addition, the retention of fine materials, are the obstacles these paper mills may encounter. In these cases, usually application of drainage/retention aids, such as nanoparticle systems can be of much help. In this due, colloidal silica and bentonite are the two of the most commonly used nano-particles with polyelectrolytes in papermaking wet-end. Therefore, in this research, the effect of bentonite and silica sol nano-particles on the performance of cationic starch was compared in terms of drainability, retention and strength properties of paperboard from recycled old corrugated containers. The analysis of the particle size for these two nanoparticles showed that although the thickness of bentonite platelets (maximum 22 nm) was less than nanosilica dimensions (less than 50 nm), the effect of bentonite-cationic starch was not significant in terms of retention, against the nanosilica. Regarding the drainability, following dosing of both silica and bentonite, the parameter much improved (up to 186% in the case of nanosilica). On the other hand, application of cationic starch containing systems in paper handsheets resulted in improvement in tensile and tear indices, however, these properties decreased following addition of nano-particles. Also, internal bonding (Scott- type) incredibly increased (up to 354%) by application of cationic starch and nanosilica. At last, generally in the case of OCC furnish, the nanosilica-cationic starch system had a better performance in terms of drainability, retention of fine materials and fiber fines and also strength properties, rather than cationic starch-bentonite.
Pulp and paper
Fatemeh Naijian; Hossein Resalati; Hamid reza Rodi; Hossein Jalali-Torshizi; Kamal Pirmoradian
Abstract
Nowadays, recycled fibers are the main fiber source for manufacturing packaging papers. Sizing of such papers, based on the type of application, is of great importance. In this research, the effect of alum-cationic rosin consumption amount in pH of about 6.5 on the properties of papers made from white ...
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Nowadays, recycled fibers are the main fiber source for manufacturing packaging papers. Sizing of such papers, based on the type of application, is of great importance. In this research, the effect of alum-cationic rosin consumption amount in pH of about 6.5 on the properties of papers made from white sheets trimmings was examined. In order to optimize consumption extent, pulp suspension sizing with alum in six level of 0, 4, 5, 7, 8, and 10 %, and rosin with the ratio of 50 % of alum based on oven dry (OD) pulp was done according to the TAPPI standard methods. Then by preparation of handsheets with basis weight of about 65±5 g/m2, their Cobb test (45 second), structural and strength characteristics were investigated. Statistical analysis of the results have shown that alum and rosin consumption amount of about 7 and 3.5 % based on OD pulp is the best suitable level for internal sizing of white sheets trimmings fibers. In these alum-rosin level, Cobb value of papers decreased from 120±11.6 g/m2 the lowest value of about 64±9.7 g/m2. Contact angle of water droplet with the paper surface increased from 24.81º to 96.53º. Paper tensile index decreased up to 125±9.7 N.m/g by such sizing level and again increased with increasing alum-rosin level. Seemingly, such phenomena can be attributed to the alum role in charge neutralizing, cellulosic fines retention and improving bonding-ability of paper network. Meaningful decrease of paper surface roughness from 10.34±0.54 µm in control sample to 8.23±1.37 µm in sized papers in optimized level confirmed this assumption.
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.
