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.
Pulp and paper
Hamid reza Rodi; Hasibeh Saeidi
Abstract
Current study was done with the aim of investigating the effect of polymeric multilayers of cationic starch and anionic starch upon CMP fibers using layer-by-layer technique on its pulp and paper properties. Consecutive cationic and anionic starches layering experiments (respectively 1% and 0.5% dose ...
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Current study was done with the aim of investigating the effect of polymeric multilayers of cationic starch and anionic starch upon CMP fibers using layer-by-layer technique on its pulp and paper properties. Consecutive cationic and anionic starches layering experiments (respectively 1% and 0.5% dose of each starch based on oven-dry fibers) with layering time of about 10 minutes were conducted to assemble one to five successive ionic starches onto CMP fibers. Pulp properties including: freeness, water retention value and zeta potential were examined. Then, handsheets with basis weight of about 60 g/m2 were prepared and their properties were analyzed. Succeeding variation of zeta potential designated formation of successive layers of starches onto the CMP fibers. Furthermore, pulp freeness and water retention value has been enlarged by increasing the number of formed layers. The results of paper properties analysis showed that bonding-ability of fibers including tensile index and burst index have been considerably improved. The prepared SEM micrographs indicated of making more bonds between fibers due to the higher absorption of cationic starch.
Pulp and paper
Seyyed Abbas Mehdikhah; Shademan Pourmousa; Aghang Tajdini
Abstract
Wet tensile strength is very important in some cellulosic health products. When these products produced during the recycling process some of the characteristics in pulp suspension due to lack of stability of desirable quality properties is difficult to achieve. In this study, using a variety of different ...
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Wet tensile strength is very important in some cellulosic health products. When these products produced during the recycling process some of the characteristics in pulp suspension due to lack of stability of desirable quality properties is difficult to achieve. In this study, using a variety of different doses of cationic polymers with laboratory methods, at first reduced the anionic charge amount in pulp suspension gradually. Then the Poly (amine) amide epichlorohydrin and its stabilizer injected to the suspension. The pulp suspension and physical properties of handsheets were evaluated. The type and amount of cationic polymers have a significant effect on the reduction of anionic charge of pulp suspension and the resulting increase in wet tensile strength and other physical resistance of handsheets. The effect of polymers resulted that anionic charge of suspension improved from 237 µeq /L in control samples to32µeq/L in the best conditions. Physical properties of handsheets improved after chemical treatments with different amounts of variety of polymers. Wet tensile strength increased than13 N/m to 121N/m, dry tensile strength improved 2730 N/m to 2860 N/m the burst resistance increased than 146 KPa to 160KPa in superior treatment using 135 mg/L of Gfloc F10. Stepwise regression analysis showed the significant relationship of the anionic charge in the pulp suspension and the physical properties of handsheets. So using different cationic polymers can be reduced the anionic charge of the pulp suspension and improved the quality properties of paper base products.
Pulp and paper
Mohammad Ahmadi; Sahab Hejazi; Kamiar Salehi
Abstract
In this study, the effect of beating time on morphologic, physical and strength properties of soda and monoethanolamine pulps obtained from wheat straw was studied, in order to optimize the time for beating operation. Beating of the pulps was applied in different time by laboratory jokromill beater. ...
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In this study, the effect of beating time on morphologic, physical and strength properties of soda and monoethanolamine pulps obtained from wheat straw was studied, in order to optimize the time for beating operation. Beating of the pulps was applied in different time by laboratory jokromill beater. The results showed that rising time of beating leads to increasing the freeness (SR) of pulps and monoethanolamine pulp reached to maximum amount of freeness (SR) in less time as compared to soda pulp. In addition, it is found that monoethanolamin pulp obtained the maximum amount of tensile index (91.3 N.m/g) after 30 min beating time and after that longer time of beating process had no significant effect on increasing the tensile index. About soda pulp it is observed that tensile index was increased significantly by rising the time of beating process and for this kind of pulp, maximum amount of tensile index (87.7N.m/g) was obtained in 50 min beating process. The highest burst index for soda pulp was 5 Kp.m2 which was obtained by 50 min beating process. About mono ethanolamine pulp burst index increased by rising time of beating Process and reached to its maximum amount (5.6 Kp.m2) and after that its amount decreased. Rising the time of beating process led to decreasing the tear index in both of kinds of pulp consist of monoethanolamin and soda pulp. The results showed that mono ethanolamine pulp had the higher yield and better beating ability in comparison with soda pulp which can be caused by better ability for carbohydrates and minerals retaining in monoethanolamin pulp.
Pulp and paper
Mina Akbari; Ghasem asadpour; noorodin nazarnezhad
Abstract
As a result of water treatment and during the water softening and hardness reducing process, calcium carbonate deposits with other impurities produced, collected and buried as mineral sludge. This study was done to investigate the effect of using calcium carbonate filler (as a byproduct of water treatment ...
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As a result of water treatment and during the water softening and hardness reducing process, calcium carbonate deposits with other impurities produced, collected and buried as mineral sludge. This study was done to investigate the effect of using calcium carbonate filler (as a byproduct of water treatment process in Mazandaran wood and paper mill) on strength properties of fluting paper produced from both old corrugated container (OCC) and neutral sulfite semi chemical(NSSC) pulps. Calcium carbonate added to the pulps at levels of 5, 10 and 15 percentage of bone dry weight of paper. The air resistant with the tensile index, burst index, tear index and resistant to fluting of handsheets were measured and compared to control handsheets (samples without calcium carbonate). The results showed that the use of calcium carbonate from the water treatment has a negative impact on fluting paper strength properties. Calcium carbonate filler negative impacts on virgin pulp (NSSC) and recycled pulp (OCC) is different and is more in OCC pulp.
Pulp and paper
Javaher Chabavizadeh; Hossein Ahmadi; Mohsen Mohammadi achachlouei; mahshid shirdavani
Abstract
Paper relics have historical, artistic and scientific values in the human cultural heritage viewpoint. Given the importance of this material, its preservation is a matter of great interest. Biodeterioration and specially fungi are one of main decay factors of cellulose structure of paper. The aim of ...
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Paper relics have historical, artistic and scientific values in the human cultural heritage viewpoint. Given the importance of this material, its preservation is a matter of great interest. Biodeterioration and specially fungi are one of main decay factors of cellulose structure of paper. The aim of this study was to determine the minimum inhibitory concentration (MIC) of Benomyl for Aspergillus niger, Aspergillus Terreus, Penicillium and Cladosporium isolated from infected papers and manuscripts. Isolates were tested for sensitivity to benomyl also been compared with each other. Fungal genera were identified based on macroscopic and microscopic characteristics of isolated samples by using slide culture method and optical microscope disk diffusion method was used In order to determine the minimum inhibitory concentration of Benomyl alcohol treatments on paper. ASTM D 2020-92 Standard Test Methods for Mildew were used to assess fungal resistance of treated paper. These test methods cover the qualitative determination of mildew (fungus) resistance of paper and paperboard, particularly those types which have been given a fungus resistant treatment. The results showed that all tested fungi are sensitive to Benomyl and Benomyl alcohol treatment prevents the growth of isolates on paper. Penicillium has the least MIC 12/5 ppm, and the highest MIC, 100 ppm, belong to Aspergillus niger. MIC obtained for Aspergillus terreus and Cladosporium was 50 ppm. In all isolates with increasing concentration of ethanolic solution of Benomyl the diameter of colonies in comparison with the control group, decreased And the percentage inhibitionof fungal growth on paper increased the results demonstrarte that the 100 ppm concentration of Benomyl in ethanol can be the lowest concentration necessary to provide an efficient antifungal action.
Pulp and paper
Mahdis Shafaee; Ali Ghasemiyan; Mohammad reza Dhghani Firozabadi; Poneh Ebrahimi
Abstract
In recent years, there has been a lot of attention in producing and using of renewable and environmental friendly cellulose film and coverage. Regarding to the application of these films and coverages in different industries such as food, packaging and medical industries, their antimicrobial property ...
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In recent years, there has been a lot of attention in producing and using of renewable and environmental friendly cellulose film and coverage. Regarding to the application of these films and coverages in different industries such as food, packaging and medical industries, their antimicrobial property is apparent. The purpose of this research is producing cellulose antibacterial film. At first, long fibr pulp convert to NFC using a supergrinder and then nanosilver treated films prepared applying silver nitrate through two different ways. In the first method, silver nanoparticles with considerations of 5 and 10 ppm reduced on NFC particles’ surface using retention aid. In second methods the prepared NFC film has been immersed in solution of Ag nanoparticle in concentration levels of 5 and 10 ppm. On higher concentration of used nanosilver solution, the amount of retained Ag nanoparticle in the first method was higher than the second one whereas, on lower concentration one, the differences of retained nanosilver values between two methods was a little. It has worth of mentioning that immerging method has the benefit of avoiding Ag nanoparticle wasting during pulp draining and nanosilver solutions could be reused simply.
Pulp and paper
Ramin Vaysi; Mohammad Nikkar; Hamidreza Salarian
Abstract
In this study, the possibility of using ash and orange bleached CMP pulp as replace in the full or part of CMP pulp of Mazandaran Wood and Paper Industries (MWPI) for making newsprint was investigated. For this purpose, first, ash and orange CMP pulps were prepared by using cooking conditions of MWPI ...
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In this study, the possibility of using ash and orange bleached CMP pulp as replace in the full or part of CMP pulp of Mazandaran Wood and Paper Industries (MWPI) for making newsprint was investigated. For this purpose, first, ash and orange CMP pulps were prepared by using cooking conditions of MWPI with 101 gr/lit Na2O at the yield 85% in 75 minutes. Then some of the CMP pulps bleached with hydrogen peroxide, then its mixed samples with 15, 30, 45 and 60 percent to CMP pulp mill (control sample). From the mixed pulps provided hand sheets with 60 gr/m2 and these optical and mechanical properties measured and the data average were analyzed and compared. The results showed that newsprint from ash CMP pulp were more suitable than CMP pulp mill in all measured properties (except brightness) and orange CMP pulp (except opacity). Following bleaching with hydrogen peroxide, the brightness, tear, burst, tensile and breaking length strengths increased and opacity decreased. The results showed that ash and orange unbleached CMP pulps are not good properties for newsprint production and these pulps have to bleach with hydrogen peroxide. In generally, the best mixed pulps were includes 45-60 percent ash and orange bleached CMP pulps with 40-55 percent MWPI CMP pulp for newsprint production.
Pulp and paper
Noradin Nazaneghad; seid najeh Mosavi; Seid Majid Zabihzadeh
Abstract
Abstract The aim of this study is investigate the effect of Tapioca and Corn cationic starch on the mechanical characteristics of paper from old corrugated containers. The paper recycling decrease its properties and affected on the paper quality. For promoting these fibers may be effective the use of ...
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Abstract The aim of this study is investigate the effect of Tapioca and Corn cationic starch on the mechanical characteristics of paper from old corrugated containers. The paper recycling decrease its properties and affected on the paper quality. For promoting these fibers may be effective the use of different treatments. Cationic starch is effective treatment for recycled fibers Promotion. In this study, the cationic starch of Tapioca and Corn, each at three different levels 0.5, 1 and 1.5 % and comparison with samples (without cationic stretch). Hand sheets with a grammag of 120 g/m2 were made and their strength properties were measured. As well as, the absorption rates of two kinds of starch on the pulp were calculated using the Acid- Phenol method. The results indicated that the use of 1.5% of Tapioca starch and 1% Corn starch had an optimum effect in increasing the strength of the produced paper. Concerning the comparison of these different types of starch, the tapioca starch was more effective than the corn starch.
Pulp and paper
fatemeh asadi; Noradin Nazarneghad; Ghasem Asadpoor atoeei
Abstract
Nowdays, algae considering marine ecosystem are regarded as producers and the first continuum that receives solar energy. Hence, they ensure the needed energy for the aquatic organism living. In global herbal division, algae have 1800 genus and 21000 types. Because of their presence in air rather than ...
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Nowdays, algae considering marine ecosystem are regarded as producers and the first continuum that receives solar energy. Hence, they ensure the needed energy for the aquatic organism living. In global herbal division, algae have 1800 genus and 21000 types. Because of their presence in air rather than underground water, algae allocate larger arena to themselves in comparise to other herbage. Based on accomplished studies, it is rated that algae have more than 7000 types in terms of biological diversity. Algae are used a lot. They are consumed in food industry, dung preparation, medicinal consumption and etc. In this study the green algae nanocellulose was used to improve CMP resistance.For the preparation of pure cellulose, algae samples initially affected the soda process and then were affected by bleaching sequence.. Next, the obtained cellulose has been converted to Nano-cellulose by using ultrasonic method. Nano-cellulose from cladophora algae was mixed with CMP in the ratios of 2, 5 and 8 percent. Finally, handmade paper was made and its resistive (strengh) properties were studied and compared with the pure hardwood CMP pulp. The results revealed that 8% treatment group had the highest density, tensile strength, burst strength, and control group had the lowest amount. Furthermore, the highest tear strength was related to control group; while, the lowest tear strength was for 8% treatment group.
Pulp and paper
Maryam Alipoor; Ghasem Asadpur Atouei; Seaid Majid Zabihzadeh; Zohreh Ghazvini
Abstract
With considering that in chemical-mechanical pulp (CMP) production process , the wood chips washing pre-treatment is important , so this research was conducted to investigate the effect of pre-treatment washing of populous deltoids wood chips on CMP Optical(brightness and opacity) and Strength(tensile ...
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With considering that in chemical-mechanical pulp (CMP) production process , the wood chips washing pre-treatment is important , so this research was conducted to investigate the effect of pre-treatment washing of populous deltoids wood chips on CMP Optical(brightness and opacity) and Strength(tensile and burst indexes) properties. Pre-treatment was accomplished with pure hot water and alkaline solutions (NaOH) at three levels of 0.5, 2 and 3.5 percent too. Pre-treated populous deltoids wood chips and control (chips without washing) were converted to pulp by CMP process. The results of this research indicated that the pretreatment of populous deltoids wood chips with hot water and also alkaline solutions caused wood chips mass and using of these treated chips for pulping caused pulp yield and brightness increscent, pulp strength reduction and also energy consumption increscent. . Removing of some part of chips hemicellulos have negative effect on the pulp refinability and cause pulp strength reduction.
Pulp and paper
Hamid reza Rudi; Morteza Nazeryan
Abstract
In this study, the effect of using Layer-by-Layer (LbL) treated pulp as mixed with refined OCC recycled pulp was investigated on paper physical properties. The LbL treatments were conducted to build 7 consecutive cationic and anionic starch layers. Afterwards, at three levels of 10, 20 and 30 percent, ...
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In this study, the effect of using Layer-by-Layer (LbL) treated pulp as mixed with refined OCC recycled pulp was investigated on paper physical properties. The LbL treatments were conducted to build 7 consecutive cationic and anionic starch layers. Afterwards, at three levels of 10, 20 and 30 percent, LbL-treated pulp was added to the 10, 15 and 20 minutes refined pulp. From mixed pulp, handsheets with basis weight of 60 g/m2 were prepared and its physical properties including: thickness, density, roughness and formation was examined. The results of LbL treatment using AFM micrographs indicated that the surface of fibers was covered with starch polymer particles by means of Layer-by-Layer treatment. Also, SEM micrographs confirm starch impregnated fibers surface and formation of rough surfaces. Analysis mutual effect of independent variables revealed that addition of LbL-treated pulp to the refined recycled pulp had only significant effect on paper thickness and surface roughness, while variation of refining time had significant influence on all physical properties. In current research, considering the results of ANOVA test and the mutual effect of the content of LbL-treated pulp and different refining time levels on the paper physical properties using response surface methodology, adding of 10 % of LbL-treated pulp to the OCC pulp and applying the refining time of about 18.66 minutes was selected as optimum condition.
Pulp and paper
Mohammad Azadfallah; Hamid Khodabandehlo; Amirabas Shaygani Akmal
Abstract
The oil-impregnated dielectric papers are the main components of distribution transformer which govern its service time. Therefore, durability enhancement of this grade of paper will cause to extend transformers life. Hence in this research long fiber unbleached Kraft pulp and mixture of it with bagasse ...
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The oil-impregnated dielectric papers are the main components of distribution transformer which govern its service time. Therefore, durability enhancement of this grade of paper will cause to extend transformers life. Hence in this research long fiber unbleached Kraft pulp and mixture of it with bagasse soda pulp with the ratio of 20% to 80% were used to make oil-impregnated dielectric papers with the grammage of 60 g/m2. The effect of dicyandiamide application with different content in paper structure and thermal aging were then assessed on dielectric properties and tensile strength of the insulation papers. The results showed that with increasing dicyandiamide content, the capacitance and tensile strength index decreased in comparison with untreated samples, but dielectric loss, insulation resistance, and breakdown voltage were improved. However, slight changes were observed in most dielectric properties during aging, but dicyandiamide caused to prevent loss of the tensile strength of insulated papers. Generally it could be concluded that dicyandiamide acts efficiently in thermal stabilization of insulation paper exposed to aggressive conditions inside the oil-filled transformer.
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.
Pulp and paper
Ahmad reza Saraeyan; Somayeh Heidari; Ahmad reza Shakeri
Abstract
Increased environmental concerns over the use of certain synthtic packaging in combination with consumer demands led to increased interest in alternative packaging materials research. Paper is biodegradable and widely used in packaging applications therefore perfectly safe for the environment. In an ...
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Increased environmental concerns over the use of certain synthtic packaging in combination with consumer demands led to increased interest in alternative packaging materials research. Paper is biodegradable and widely used in packaging applications therefore perfectly safe for the environment. In an effort to produce more environmentally friendly materials, renewable and biodegradable biopolymers have been utilized as paper coating substances. in this study carried out to determine effect of the four type of biopolymers such as anionic starch, chitosan, polyvinyl alcohol and etylenvinyl alcohol, on the smoothness, Water absorption, air resistance, burst Index properties paper made of bagasse soda pulp. Coating done whith coater tester. Coating weight was 3-6 g/m2. The results of the mechanical and physical properties of the handsheets showed that, led to increase index burst handsheets coated with etylenvinyl alcohol and anionic starch indices as 34.4 and 26.26% compared to control sample. Air resistance and smoothness was for coated paper with starch more than control sample indices as 173.23 and 18.73%. also coated paper with chitosan showed minimum value..
Pulp and paper
Sahba Aliniyay Lakani; Elyas Afra; Hossein Yousefi
Abstract
In this research, nano fibrillated cellulose, as a reinforcement nano material and environmentally biodegradable material which has recently attracted the attention of most researchers and paper producers, has been added to chemi-mechanical pulp used for manufacturing of liner board at different charges ...
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In this research, nano fibrillated cellulose, as a reinforcement nano material and environmentally biodegradable material which has recently attracted the attention of most researchers and paper producers, has been added to chemi-mechanical pulp used for manufacturing of liner board at different charges of 5, 20, 50 and 100% in two different levels of freeness. Also, the effect of wet press, one of the the most important processing agents on the properties of paper reinforced with nano fibrillated cellulose, in two levels of press pressure which included 3 and 6 bar, has been investigated. Finally, physical, barrier and strength properties of the papers produced have been measured according to TAPPI test methods. Addition of nano fibrillated cellulose was resulted in improved tensile and air resistance of chemi-mechanical pulp and increasing trend in improving of these properties with increase in press pressure was one of the important achievements of the present research.
Pulp and paper
Farhad Zeinaly; Ahmad Reza Saraeian; Mohammadhadi Aryaei monfared; Ali Kazemi Tabrizi
Abstract
In conducting environmentally friendly processes for pulp production, first step is to reduce the effluent pollution load in each stage, and because the bleaching process is the most polluting stage in the production of pulp, improving it is one of the most important matters. The first act to ameliorate ...
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In conducting environmentally friendly processes for pulp production, first step is to reduce the effluent pollution load in each stage, and because the bleaching process is the most polluting stage in the production of pulp, improving it is one of the most important matters. The first act to ameliorate bleaching process of chemical pulps is the reduction of colored materials, mostly lignin, which enter to the bleaching section. Thus, the use of oxygen delignification stage after pulping and before bleaching process is the key stage in improving process and cleaner production. In this study, the effect of conducting oxygen-delignifying treatment by two kinds of machines, and under different process condition, on chemical, physical, mechanical and optical properties of bagasse soda pulp was investigated. The bagasse soda pulp with the kappa number of 20, 955 ml/g viscosity, and 37% ISO brightness was prepared from Pars Hafttapeh Company. 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, by two kinds of machines. Results indicated that oxygen delignification treatment led to intense decrease in pulp kappa number, while the pulp viscosity did not change. 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. The pulp brightness was increased about 4-6%. And also, due to the need of shorter time in order to reach the reaction temperature in the Iranian made machine, pulp delignifying by this machine was a little lower than Quantum machine.
Pulp and paper
Ramin Veisi; Rabi Behroz; Iman Khajeh Ali
Abstract
This study and it aim was accomplished on the effect of ECF bleaching on optical and mechanical properties of bagasse soda pulp. For this purpose, some soda unbleached pulps were randomly selected from Pars mill. Then these pulps were bleached with OD(Ep)P and OD(Ep)D stages by oxygen, chlorine dioxide ...
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This study and it aim was accomplished on the effect of ECF bleaching on optical and mechanical properties of bagasse soda pulp. For this purpose, some soda unbleached pulps were randomly selected from Pars mill. Then these pulps were bleached with OD(Ep)P and OD(Ep)D stages by oxygen, chlorine dioxide and hydrogen peroxide. The hand sheets with 60 gr/m2 were prepared from soda unbleached and bleached from EH(control), OD(Ep)P and OD(Ep)D stages pulps, then the optical and mechanical properties were measured and compared according by using TAPPI Standard test methods. The results showed that residual lignin and kappa number decreased following above-mentioned of bleaching stages. The brightness, greenness and K/S ratio were increased in bagasse soda pulps by bleaching. In different treatments, the brightness, opacity, absorbance coefficient, burst, breaking length, tensile, tear strength sensible increased in OD(Ep)P and OD(Ep)D as compared with EH (control) mill bleaching stages. In general, first OD(Ep)P stage, then OD(Ep)D were better than EH (control) mill stage in more of were measured properties.
Pulp and paper
Mohammad Azadfallah; Hamid khodabandehlo; Amir abas Shayeghani akmal
Abstract
The properties of transformer electrical insulating papers are influenced by fiber chemical modification process. In this research, the effect of cyanoethylation of fibers and addition of cyanoethylated cellulose nanofiber (CNF) on dielectric properties including capacitance, dielectric ...
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The properties of transformer electrical insulating papers are influenced by fiber chemical modification process. In this research, the effect of cyanoethylation of fibers and addition of cyanoethylated cellulose nanofiber (CNF) on dielectric properties including capacitance, dielectric loss, insulation resistance, breakdown voltage as well as tensile strength of two grade of handsheets made of unbleached long fibers and its mixture with bagasse soda pulp (with the ratio of 1:1) were evaluated after impregnating with mineral oil. Cyanoethylation of CNF and pulp fibers was performed by grafting of acrylonitrile under alkaline condition at 40 ̊C and room temperature respectively. Then, the nitrogen content of cyanoethylated samples was determined using Kjeldahl method and degree of substitution (DS) was calculated. The results showed that cyanoethylation of pulp fibers and CNF decreased the capacitance and tensile strength of insulated papers. It was also observed that the chemical modification imposed slight effect on dielectric loss, but insulation resistance and dielectric voltage were increased.
Pulp and paper
Mehrnoosh Tavakoli; saraeyan ahmad reza; hossein resalati; ali ghasemian
Abstract
The present study was carried out aiming to investigate the effect of using Deinked Mixed Office Waste Pulp (MOW) on the properties of Alkaline Peroxide Mechanical Pulp (APMP) from cotton stalk. APMP pulps was prepared using chelating agents such as Na2SiO3 and DTPA (control sample) and without ...
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The present study was carried out aiming to investigate the effect of using Deinked Mixed Office Waste Pulp (MOW) on the properties of Alkaline Peroxide Mechanical Pulp (APMP) from cotton stalk. APMP pulps was prepared using chelating agents such as Na2SiO3 and DTPA (control sample) and without these agents in two-stage pulping withL/Wratio 6:1(ml/g), 20 minutes impregnation time at 70 0Cfor firststage, 60 minutes impregnation at 75 0Cfor second stage. Also, pulp was preparedfrommixed office waste paper, whichweredeinked with conventional flotation and then each pulp was separately refined up to about 300 ml CSF. The handsheets were made from control sample pulps, APMP without chelating agents, MOW deinked pulp and mixing with 10%, 20% deinked pulp with control APMP. Physical and mechanical properties were determined using TAPPI standard methods. Deinked MOW pulp had the maximum values of density, brightness, strength properties and APMP pulp without chelating agents had the minimum values. Among mixed pulps, APMP pulp containing 20% deinked MOW pulp showed the maximum value of density, brightness, burst index and tear index.
