Noraldin Nazarnezhad; mahin avrand; Hosin Resalati
Abstract
One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, much research have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides ...
Read More
One of the problems of papers and cardboards in the packaging industry is the poor resistance to water, gas, and oil penetration. Nowadays, much research have been done on the use of biodegradable films and coatings based on polysaccharides to solve this problem. Chitosan is one of these polysaccharides that can be used as a biodegradable coating in packaging papers. In this study, the effect of chitosan on the strength and barrier properties of coated liner paper was investigated. Chitosan was used in three levels 10, 15, and 20 g/L acetic acids (1%) and with two softener ratios (glycerol) of 0.5 and 1 (based on dry weight of chitosan) for papers coating. Strength properties including tensile, burst and tear index and barrier properties including water absorption, air resistance, and oil absorption in the coated samples were investigated. The Statistical analysis of results showed that the barrier properties increased significantly. Also, the effect of increasing the concentration of softener in the coating solution on the properties of air resistance and oil absorption was positive but negative for water absorption. The basis weight, burst and tear index of the coated samples increased with increasing coating weight, on the other hand the tensile strength decreased. Moreover, increasing the concentration of softener in the coating solution showed a negative effect on the properties of the samples. The results of the scanning electron microscope images showed that formation of chitosan film and the increase in the uniformity of the liner paper surfaces, especially in higher consumption amounts.
rouzbeh asadi khansari; Mohammadreza Dehghani Firouzabadi; Hossein Resalati
Abstract
The purpose of this research is to evaluate the effect of various paper coatings on initial contact angle and its evolution over time. We investigated nine coatings on two types of 75 g and 125 g printing papers. Seven coating compositions containing 80% clay, 20% ground calcium carbonate, dispersing ...
Read More
The purpose of this research is to evaluate the effect of various paper coatings on initial contact angle and its evolution over time. We investigated nine coatings on two types of 75 g and 125 g printing papers. Seven coating compositions containing 80% clay, 20% ground calcium carbonate, dispersing agent and various levels of polyvinyl acetate and lactic acid as binders were used. In the last two coatings, we used 100% precipitated calcium carbonate pigments, cationic starch, methacrylate, dispersant and two levels of cellulose nanofibers. In these suspensions, the amount of cellulose nanofibers in composition 8 is twice composition 9. After coating using rod method, the papers were dried then coated and control samples were calendered. We then performed contact angle measurements using water droplet and Kit No were performed. We noticed largest contact angle and smallest angle change over time for sample 6 containing 75% binder. Last two coatings contained cellulose nanofibers, which caused presence of hydroxyl group on the surface and lowered the contact angle. Composition eight was the most hydrophilic sample. Best barrier property Kit No and largest droplet volume after 20 seconds was accompanied with the increase of the binder percentage in the formulation. For the control sample and three treatments with highest binders, the contact angle over time remains relatively constant which is a sign of hydrophobicity. The correlation between contact angle and volume of the water droplet was determined to be 0.951 and 0.936 in the 75g and 125g papers relatively. We did not notice a significant difference in contact angle and Kit No between 75g and 125g samples.
Pulp and paper
ali barzan; hossein resalati; ali ghasemian; ahmadreza saraeyan; ghasem asadpour
Abstract
In this study, the effect of pigment composition on the properties of paper prepared from CMP pulp was studied. There for 3 different pigment combinations (100% calcium carbonate (GCC), 70% calcium carbonate and 30% kaolin clay (70GCC30Clay) and 70% calcium carbonate and 25% gritty and 5% titanium dioxide ...
Read More
In this study, the effect of pigment composition on the properties of paper prepared from CMP pulp was studied. There for 3 different pigment combinations (100% calcium carbonate (GCC), 70% calcium carbonate and 30% kaolin clay (70GCC30Clay) and 70% calcium carbonate and 25% gritty and 5% titanium dioxide (70GCC25Clay5TiO2)) were made with anionic starch, latex and dispersersant and Used for coating. Physical properties included (surface roughness of the paper, Ash content and Apparent density) And the optical properties included (brightness, absorption and diffusion coefficient) and paper resistance characteristics including tensile strength, bursting resistance, tear strength based on standard TAPPI standardized measurements and Using factorial design, analysis of variance was performed and the mean of paper properties was compared with Duncan's test. The purpose of this research is to achieve the best combination for coating the paper with the improvement of physical and optical properties and maintaining resistance properties. By adding clay and dioxide titanium to calcium carbonate, the roughness of the paper surface decreased The highest roughness of the surface of the paper in the diet was observed for the control paper and the lowest was seen in the treatment of 70GCC30Clay surface. Also, the highest degree of brightness is related to 70GCC25Clay5TiO2 treatment. The highest index of tensile strength and burst strength index was related to gypsum treated paper (GCC) and also the highest tear strength index for treated paper at level 2 (70GCC30Clay).
Chemical conversion
Hamedeh Kiani; Hosein Resalati; Seyed Hassan Sharifi
Abstract
Carboxymethyl cellulose (CMC) is one of the important cellulose derivatives in industries, which is widely used as anti-caking agent, emulsifier, stabilizer, dispersing agent, thickener, and gelling agent. The main raw material of cellulose derivative is cellulose from wood and cotton linter. In this ...
Read More
Carboxymethyl cellulose (CMC) is one of the important cellulose derivatives in industries, which is widely used as anti-caking agent, emulsifier, stabilizer, dispersing agent, thickener, and gelling agent. The main raw material of cellulose derivative is cellulose from wood and cotton linter. In this study, the cotton linter alpha-cellulose was used for producing CMC. Acidified sodium hydroxide process was applied to extract the cellulose from linter alpha-cellulose. Carboxymethyl cellulose was then prepared from cellulose. The optimization of reaction conditions was studied by using response surface methodology (RSM). The design experiment is Box-Behnken design consists of 3 factors (reaction time, % NaOH in mercerization process and mass ratio of monochloroacetic acid to cellulose in etherification process) with 3 levels. Based on it, the optimum values of independent variables are the reaction time of 54.23 min, NaOH concentration of 41.25 % and mass ratio of MCA to cellulose of 1.44 which the CMC had the DS of 0.656, the viscosity of 6634.76 cP. Fourier Transform Infrared spectra (FTIR) were used to characterize the product and starting Cotton Linter Alpha-cellulose.
Pulp and paper
Moghadaseh Akbari; Hossein Resalati; Ahmad reza Saraeyan; Mohammad reza Dehghani Firoz Abadi
Abstract
During the paper manufacturing process, especially when mechanical pulp or recycled pulp used, a large amount of soluble and colloidal substances (DCS) are comprised and dispersed or dissolved in the process water. Accumulation of DCS during the papermaking operation with the increasing closure process ...
Read More
During the paper manufacturing process, especially when mechanical pulp or recycled pulp used, a large amount of soluble and colloidal substances (DCS) are comprised and dispersed or dissolved in the process water. Accumulation of DCS during the papermaking operation with the increasing closure process water systems, can have a variety of deleterious effects on papermaking process and paper products. In this study, The effect of anionic trash neutraliziation was investigated by using different catcher anionic tarsh and also pulp washing (removal of anionic trash) on the CMP pulp and paper properties. After the initial preparation chemi-mechanical pulp (CMP), bleached long fiber kraft pulp and mixing the pulps with each other, filler of precipitated calcium carbonate (PCC) was added. Then a cationic retention aid That in this research has been cationic polyacrylamide were added to the mix. To neutralization of and reduce the negative effects of anionic trash, different levels of poly DADMAC with molecular weight 100000-200000 (0.025, 0.05, 0.1, 0.15%) and poly aluminium chloride (PAC) (0.1, 0.25, 0.5%) was added before adding of retention aid. Results showed that the use of different neutralizers imprived of zeta potential and drainage time of pulp, and increase of total retention; but reduces burst index of paper that was not significant statistically. CMP pulp washing and drainage treatment caused reducing COD and on the other hand reduced the amount of anionic trash with organic origin. Washing treatment pulp improved drainage time from pulp, total retention; but reduced burst index. Based on these findings, using cationic polyelectrolyte can introduce as a good strategy to reduce the harmful effects anionic trash and more retention suspension components.
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, ...
Read More
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 ...
Read More
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
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 ...
Read More
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
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 ...
Read More
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
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 ...
Read More
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
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 ...
Read More
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.
Pulp and paper
Ali Barzan; Hossein Resalati; Ghasem Asadpour atoei
Abstract
After water purification and softening, a lot of calcium carbonate with other impurities produce and these byproducts gather and bury as mineral sludge.In this research, The quality of calcium carbonate from water softening process in mazandran wood and paper industry (MWPI) mill and effects of loading ...
Read More
After water purification and softening, a lot of calcium carbonate with other impurities produce and these byproducts gather and bury as mineral sludge.In this research, The quality of calcium carbonate from water softening process in mazandran wood and paper industry (MWPI) mill and effects of loading of this byproduct on fine paper production was investigated and the results were compared with other industrial fillers like grounded calcium carbonate(GCC) and precipitated calcium carbonate(PCC) and also china clay (kaolin).From the paper structural viewpoint , the fine paper that filled with water softening calcium carbonate (derived after water softening process) have more bulk(bulkier) and more porous and rougher surface compare to fine papers that filled with the common industrial fillers.From the paper strength properties viewpoint , the fine paper that filled with water softening calcium carbonate have less decrease in tensile and burst strength but have not suitable tear strength properties. From the paper optical properties viewpoint, the fine paper that filled with water softening calcium carbonate, because of particles size and impurities of this filler have the least light scattering coefficient and consequently have less brightness and opacity.Adding of 10 and 20 percent precipitated calcium carbonate to by water softening calcium carbonate cause paper porosity and strength decreasing but the optical properties of hand sheets was increased.
Pulp and paper
Mostafa Nikkhah Dafchahi; Hossein Resalati
Abstract
This research was performed to evaluate the potential of acid pre-hydrolysis soda-AQ process for the production of dissolving pulp including high α-cellulose content from Populus deltoides. To achieve the aim, a pre-hydrolysis liquor containing 0.06% acid sulfuric, soda-AQ pulping, and OD0ED1 bleaching ...
Read More
This research was performed to evaluate the potential of acid pre-hydrolysis soda-AQ process for the production of dissolving pulp including high α-cellulose content from Populus deltoides. To achieve the aim, a pre-hydrolysis liquor containing 0.06% acid sulfuric, soda-AQ pulping, and OD0ED1 bleaching sequence were used. The results show that using at least 0.40 kappa factor at D0 stage was necessary to gain access a high quality dissolving pulp including characteristics like having brightness level and α-cellulose content higher than 86% and 98%, respectively. A kappa reduction of 40.3% was achieved by performing a single stage oxygen delignification after soda-AQ pulping to drop kappa number of pulp from 14.1 to 8.4 prior to entrancing the pulp into the final bleaching stage. The results illustrated that producing acid pre-hydrolyzed soda-AQ dissolving pulp including high α-cellulose content and brightness, and even viscosity is completely feasible through controlling and optimizing the acid pre-hydrolysis, pulping, oxygen delignification stages, and D0ED1 bleaching sequence.
Pulp and paper
Moghadaseh Akbari; Nadia Kabodi torabi; Hossein Rrsalati; Gasem Asadpour atoei; Mohammad reza Dehghani firozabadi
Abstract
Aim of this study is precipitated calcium carbonate cationic modification and comparison of impact of using its with conventional filler (unmodified) on strength properties of paper. One of the defects of adding fillers to paper is decreasing of mechanical strength of paper because of reduction in bonding ...
Read More
Aim of this study is precipitated calcium carbonate cationic modification and comparison of impact of using its with conventional filler (unmodified) on strength properties of paper. One of the defects of adding fillers to paper is decreasing of mechanical strength of paper because of reduction in bonding area between fibers. In this study whit purpose of maintaining the strength of paper, and change the surface charge of precipitated calcium carbonate and replace it with conventional fillers are used.in this research with aim of precipitated calcium carbonate and replacing it with conventional filler was used. Condition of cationic precipitated calcium carbonate preparation was 90 ċ temperature, 3 hours time and 55% water content of cooking process. loading amount of starch was 9, 12 and 15 percent based on precipitated calcium carbonate weight.Papers made at three level: 10, 16, 30 percent of filler in paper sheets contain conventional fillers were compared. Results indicated that papers containing modified-filler have more values of retention rather than those with unmodified filler, both in 20% and 30% filler dosages.papers contained cationic filler have more mechanical strength index in respect of papers contained conventional fillers.
Pulp and paper
Nazbakht Hezbi; Elyas Afra; Hossein Resalty
Abstract
In this research, the effect of different steps of enzymatic treatment including enzymatic pre-refining and post-refining by Endoglucanase was investigated on the quality of OCC pulp. Three pulps including a: control sample (without enzyme addition), b: enzymatic pre-refining (enzyme treatment + refining) ...
Read More
In this research, the effect of different steps of enzymatic treatment including enzymatic pre-refining and post-refining by Endoglucanase was investigated on the quality of OCC pulp. Three pulps including a: control sample (without enzyme addition), b: enzymatic pre-refining (enzyme treatment + refining) and c: pre and post enzymatic refining (enzyme + refining + enzyme) were made from OCC pulps. Enzymatic treatment was done at optimum conditions before determined (concentration of 1u and time duration of 0.5 hour) under constant process conditions and refining accomplished at given revolution of 2000. Obtained results from this research indicated that applying enzymatic pre-treatment had efficient in improving the physical and mechanical of paper and showed the highest strength than to the other treatments. Using Endoglucanase at two stages (before and after refining) caused to improve pulp drainability and decrease the paper strength properties. In general, the maximum tear index was observed in enzymatic pre-refining step.
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 ...
Read More
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.
Saeid Kamrani; Ahmad reza Saraeian; Hossein Resalati; Ali Ghasemian
Abstract
The main objective of this study was to determine the trends of fiber dimension variation along the longitudinal direction of wheat straw as a criteria for papermaking. Zagross wheat straw was collected from the agricultural and natural resources research center, Golestan province .The fiber biometric ...
Read More
The main objective of this study was to determine the trends of fiber dimension variation along the longitudinal direction of wheat straw as a criteria for papermaking. Zagross wheat straw was collected from the agricultural and natural resources research center, Golestan province .The fiber biometric characteristics including fiber length, fiber diameter, lumen diameter and cell wall thickness in three internodes were determined .Results showed that, the difference in fiber diameter, lumen diameter and cell wall thickness were sttistically significant between three internodes of wheat straw at 99% confident Based on the computed papermaking indices (flexibility ,softness and runkle number), it was predicted that the papers produced from the first and the third internode of wheat straw may have higher tensile,folding and burst strength and the papers produced from the second internode may have higher tear strength.
Pulp and paper
Saeideh Sharifi; Ahmad reza Saraeyan; Hossein Resalati
Abstract
Preparation and pre-treatment of raw material influences the pulp production time and color elimination. Pulp consistency during the treatment also influences the color reaction. In the preparation of the APMP pulp, bagasse was pretreated by either boiling water, 1% NaOH as well as 1% NaOH + 1% ...
Read More
Preparation and pre-treatment of raw material influences the pulp production time and color elimination. Pulp consistency during the treatment also influences the color reaction. In the preparation of the APMP pulp, bagasse was pretreated by either boiling water, 1% NaOH as well as 1% NaOH + 1% H2O2. The liquor to bagasse ratio, treatment time and temperature of alkaline peroxide treatment were constant as 10:1, 30 min, and 70 °C respectively. The treatment duration was determined so that at least five percent of the initial hydrogen peroxide remained at the end of chemical treatment. Characteristics of hand sheets were determined according to the TAPPI standard. The results showed that, the duration of the treatment for pulp consistency of 10, 15 and 20% was 50, 30 and 10 minute, for sample pretreated with boiling water and 290, 230 and 170 minute for the sample pretreated with 1% NaOH + 1% H2O2. The highest brightness of the paper reached with bagasse pretreated in boiling water at 20 % consistency.
Iman Akbarpoor; Hossein Resalti; Ali Solimani
Abstract
In this study, the effect of elimination and relative decrease of sodium silicate along with substituting the organic complex of sulvy-x was investigated on optical properties of CMP pulp bleached by hydrogen peroxide. The brightness of paper were increased to 66.8%, yellowness decreased to 22% and opacity ...
Read More
In this study, the effect of elimination and relative decrease of sodium silicate along with substituting the organic complex of sulvy-x was investigated on optical properties of CMP pulp bleached by hydrogen peroxide. The brightness of paper were increased to 66.8%, yellowness decreased to 22% and opacity decreased to 80% with increase in sodium silicate charge from 0.7% to 3%. Also, with complete elimination of sodium silicate and using of sulvy-x at different levels of 0.4, 0.5, 0.7 and 1% , highest brightness and lowest yellowness were shown at 0.5% sulvy-x. These values were 66.1% and 21.8%, respectively. The brightness of paper enhanced from 61.2% to 67.3% with increasing of sulvy-x charge from 0.4% up to 0.5% blended with constant value of 0.7% sodium silicate. But the brightness decreased at higher levels. Generally, pretreatment by DTPA prepared the paper with lower brightness and higher yellowness at two different states namely silicate-free and silicate-containing with sulvy-x. Pretreatment by DTPA at silicate-free state led to decrease of opacity but at silicate-containing state terminated to improve of opacity values. Increasing of bleaching time up to 120 minutes resulted in the paper with higher brightness, higher opacity and lower yellowness at silicate containing state with sulvy-x. At silicate-free state, increasing of bleaching time up to 120 minutes led to improve of opacity while brightness improved and yellowness reduced with increase in bleaching time to 90 minutes. Also, the brightness of paper decreased at higher times (120 minutes) and yellowness increased. In conclusion, achieved results from comparison of optical properties of paper produced from peroxide bleaching of hardwood CMP pulp indicated that we could produce the paper with desirable or even better optical properties by replacing of sulvy-x rather than sodium silicate compared to conventional peroxide bleaching.
Pulp and paper
Mohammad taghi Asdolah zadeh; Hossein Resalti; Ali Ghasemian
Abstract
In the present study the effects of hot water pre-extraction and alkaline catalyzed were evaluated on soda-aq pulping of kenaf whole stem. In this respect, following kenaf chips pre-extraction at various temperature and time conditions, pulp preparation were carried out on oven-dried weight loss levels ...
Read More
In the present study the effects of hot water pre-extraction and alkaline catalyzed were evaluated on soda-aq pulping of kenaf whole stem. In this respect, following kenaf chips pre-extraction at various temperature and time conditions, pulp preparation were carried out on oven-dried weight loss levels of 8.5, 11.5 and 14.5 % of the samples, and the reference untreated kenaf chips performed by using Soda-AQ at 3 levels of H-factors ( 983, 1408 and 1832 hours). Results indicated that kenaf chips weight losses increased while the pre-extracted pH decreased as pre-extraction temperature and time increased. The required H-factor for achieving certain level of weight loss was reduced by adding small amounts of alkali (0.15 % on oven dried kenaf) on hot water extraction stage. The Pulp yields were reduced by increasing cooking H-factor and extracted weight loss. Averages comparison indicated that significant differences were observed, at 95% confidence, between the pulp yield and kappa number from reference pulp and pre-extracted pulp samples at levels of about 8.5, 11.5 and 14.5 %, and pulp yields and their kappa number were higher in reference pulps than pre-extracted samples. In addition, pulp yield average was higher in pre-extracted samples by alkaline catalyzed than pre-extracted samples by hot water, however, no significant differences were observed between their kappa number average. Meanwhile, to obtain a certain (similar) kappa number, pre-extracted kenaf chips in comparison with reference untreated kenaf chips require lower H-factor.
Pulp and paper
Ali Solimani; Hossein Resalati; Eiman Akbarpoor
Abstract
In this research, effects of mixing the birch wood with hornbeam and beach on optical and physical properties of papers produced at constant freeness range of 300 ml, CSF and yield of 85% and reference of CMP pulp (75% hornbeam plus to 25% beach) was investigated. CMP pulp was produced from birch ...
Read More
In this research, effects of mixing the birch wood with hornbeam and beach on optical and physical properties of papers produced at constant freeness range of 300 ml, CSF and yield of 85% and reference of CMP pulp (75% hornbeam plus to 25% beach) was investigated. CMP pulp was produced from birch chips at 10,20,30 and 40% content within the conditions of pulp yield:85%, liquor to dried chip ratio (L/W) of 7/1, sulfite percent of 20% on oven-dried wood chips, cooking temperature:1600C, cooking time:85-135 minutes blended with 60-90 % hornbeam and beach. After defibration and refining the cooked wood chips, the standard hand sheets of 60 g/m2 were made from different pulps and the optical and physical properties of paper produced were compared. The results from comparing the optical properties of paper showed that using up to 40% birch chips blended with hornbeam and beach led to brightness improvement and yellowness and opacity reduction compared to control CMP pulp. Increase of birch use to 30% indicated no significant effect on opacity values at confidence level of 99% compared to control CMP pulp. Utilizing 40% birch resulted in the preparation of papers with lower caliper, smoother surface and higher air resistance.
Iman Akbarpoor; Hossein Resalati; Ahmad reza Saraeian
Abstract
In this study, deinking of waste newspaper was investigated by conventional and enzymatic methods. Conventional deinking was done in pulping times of 10, 20 and 30 minutes along with different processes of washing, flotation and combined washing/ flotation. Enzymatic deinking was accomplished ...
Read More
In this study, deinking of waste newspaper was investigated by conventional and enzymatic methods. Conventional deinking was done in pulping times of 10, 20 and 30 minutes along with different processes of washing, flotation and combined washing/ flotation. Enzymatic deinking was accomplished at different charges of 0.025, 0.05, 0.1 and 0.2% cellulase enzyme (based on oven-dried waste paper), pulping times of 10,15 and 20 minutes, pH range of 5-5.5 along with one-stage washing process. Optimum compositions were selected from chemical and enzymatic treatments and then physical and mechanical properties of the paper produced in optimum conditions were compared. Achieved results from comparison of the physical properties of optimum chemical and enzymatic treatments showed that, the paper produced from deinked pulp by conventional method had higher calliper, bulk and porosity. Using of 0.1% cellulase resulted the papers with higher tensile and breaking length compared to chemical treatments. The papers could be produced with similar burst and tear indexes compared to chemical treatments using of 0.1% cellulose, as well.
Pulp and paper
Iman Akbarpour; Hossein Resalati
Abstract
This research was accomplished in order to investigate the replacement of organic complex of Glanapone Stab with sodium silicate on optical properties of hardwood CMP pulp bleached by hydrogen peroxide. The highest brightness of 65.5% and the lowest yellowness of 21.6% was attained at silicate-free ...
Read More
This research was accomplished in order to investigate the replacement of organic complex of Glanapone Stab with sodium silicate on optical properties of hardwood CMP pulp bleached by hydrogen peroxide. The highest brightness of 65.5% and the lowest yellowness of 21.6% was attained at silicate-free followed by replacement of 0.7% and 1.5% Glanapone. But the highest opacity 98.2% was gained using 0.5% glanapone. The brightness of paper increased to 68.1% and the yellowness decreased to 20.8. by adding of glanapone consumption from 0.4% to 0.5% in blended with 0.7% sodium silicate. At higher levels than 0.5% glanapone, the brightness of paper decreased and the yellowness increased. Using Higher levels of 1 and 1.5% glanapone in blended with 0.7% sodium silicate resulted the highest opacity 97.9% and 98%, respectively. Increasing of peroxide usage up to 5% at two different states of silicate-free and silicate-containing with glanapone resulted in the paper with higher brightness and lower yellowness and opacity. CMP pulps bleached at 120 minutes resulted the highest brightness of 71.1% and the lowest yellowness of 18.3% at silicate-containing state with glanapone. Maximum opacity of 98.3% and 98% were shown at bleaching time 30 minutes at two states silicate-free and silicate-containing state with glanapone, respectively. In this research with regard to optical properties in relation to paper produced from CMP pulp bleaching at two states silicate-free and silicate-containing with glanapone,it can be said that possibility of producing the paper with similar optical properties or even better using 0.7% or 1.5% at silicate-free is in compared to conventional hydrogen peroxide bleaching. Also, we could produce the paper with higher brightness along with lower yellowness and similar opacity followed by bleaching time of 120 minutes and hydrogen peroxide 5% in combination of 0.7% sodium silicate with 0.5% glanapone in compared to higher consumed values of sodium silicate.
Pulp and paper
Hossein Resalti; Morteza Abdolah bik marandi; Ahmad reza Saraeyan
Abstract
The effect of using commercial xylanase enzyme in prebleaching of bagasse kraft pulp was investigated. Xylanase enzyme from Trichoderma viride was added to pulp at various doses of 10, 25 and 50 IU/g pulp for reaction time 2h and then the enzyme treated pulp was bleached in ADED sequences (Acid sulfuric ...
Read More
The effect of using commercial xylanase enzyme in prebleaching of bagasse kraft pulp was investigated. Xylanase enzyme from Trichoderma viride was added to pulp at various doses of 10, 25 and 50 IU/g pulp for reaction time 2h and then the enzyme treated pulp was bleached in ADED sequences (Acid sulfuric +Dioxide chlorine 4, 6, 8, 10% + Alkaline extraction + Dioxide chlorine 2% as available chlorine). The results have shown that with increased dioxide chlorine in D1 bleaching sequence, final brightness of bleached pulp was increased significantly (P<0.01). Furthermore, in the case of treated samples by xylanase enzyme optical properties of bleached pulp such as brightness and opacity were increased significantly (P<0.01). For yellowness, revolution of refiner for distinct pulp freeness and kappa number have shown decreased significantly (P<0.01). Maximum of brightness and minimum of kappa number and yellowness were belong to 25 IU/g pulp treatment that about 10.8, 3.98% and 2.24 unit have difference significantly (P<0.01) as compared with control sample respectively. Maximum of opacity and Minimum was belong to 50IU/g pulp treatment that about 3 and 13.24% have difference significantly as compared with control sample respectively. Regardless of obtained results 25IU/g pulp treatment could be selected as optimal treatment.
Pulp and paper
Said mohammad Mazhari mosavi; Saeed Mahdavi; Syed zyaldin Hosseini; Hossein Resalti; Hossein Usefi
Abstract
This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. ...
Read More
This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. Cellulose, lignin, extractive material (acetone solved) and ash were measured 41.66, 16.00, 1.63, and3.46 percent, respectively. Cooking condition was determined as follow: Soda as 16, 18, and 20 percent on the basis of rapeseed dry straw, temperature was set at 175 and 185 Cº, cooking time was set at 40 and 70 minutes, and straw to liquid ratio was set at 1/8. The amount of anthraquinone added to cooking liquor was 0.2%, based on rapeseed dry straw. Using severe cooking factors caused reduction of yield and Kappa number in both methods. Refining was performed on selected pulps in order to reach 35025 (ml,CSF) freeness. The 60 gr/m² hand sheets were made in order to determine mechanical strength and physical properties. Average thickness, density and bulk is measured at 86.4µ, 0.69gr/cm³ and 1.44cm³/gr respectively. Average tear index, burst index, breaking length and tensile indexare measured at 4.6 mN.m²/gr, 3.5 kpa.m²/gr, 7.4km and 72.6Nm/g respectively.
The results showed that however screen yield of rapeseed straw pulp is low but kappa number and mechanical properties of pulp is suitable,compared with the other agriculture residues, so Rapeseed pulp can be used in paper making industries.
