Pulp and paper
Ramin Vaysi; Iesa Rezazadeh; S. ESHAGH EBADI
Abstract
Background and aim: Today, with the increase in population, increasing demand for paper, as well as greater restrictions on raw materials, the production of pulp from high-yield pulps and mechanical pulps has found a special place. These pulps have a high yield greater than 85%, but due to the presence ...
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Background and aim: Today, with the increase in population, increasing demand for paper, as well as greater restrictions on raw materials, the production of pulp from high-yield pulps and mechanical pulps has found a special place. These pulps have a high yield greater than 85%, but due to the presence of lignin, extracts, and metal ions, their use is limited to short-term usage, as in the long run they suffer from brightness reversion and photo-yellowing. This study aimed to investigate the effect of DTPA, nano-cellulose, and nano-chitosan spray on the optical properties of chemical-mechanical pulp (CMP). Materials and methods: For this purpose, first, a quantity of bleached chemical-mechanical pulp (CMP) was selected as a control sample from Mazandaran wood and paper industry. Papers with a base weight of 60 gr/m2 were prepared from the mentioned paper pulp. In this study, the nano-fibrillated cellulose (NFC) was purchased from Nano Novin Polymer Co. (Sari, Iran), which was prepared from softwood alpha cellulose pulp with an average fiber diameter of 32 nm. The NFC was loaded at 2% by spraying onto papersheets. Nanochitosan (“Seafresh”, Thailand), obtained from exoskeletons of crustaceans, with a deacetylation degree of 93% and a molecular weight of 270 kDa was used. Nanochitosan was loaded at 1 and 2% of the dry pulp weight. Diethylene triamine penta acetic acid (DTPA) was prepared from DIPER-Samchun (South Korea), with a 50% solid content and 25 cps viscosity. To spray the DTPA onto the paper surface, 0.5% DTPA was prepared. To prepare samples for the surface modification, paper sheets with a basis weight of 60 g/m2 were made. Then, 0.5% DTPA, 2% nanochitosan, and 2% nanocellulose were sprayed separately on the papersheets. In addition, another treatment named mixed-solution (containing 0.5 % DTPA + 2% nanochitosan + 2% nanocellulose) was sprayed onto the handsheets. The spraying time and distance were 20 s and 20 cm, respectively, and the treatment process was named “spray-coated”. Then, the optical properties (brightness, opacity, yellowness, and greenness) of the hand-sheets were measured according to ASTM and TAPPI standard methods. Results:The results showed that by DTPA, nano-cellulose, and nano-chitosan spray in the handsheet paper, brightness, yellowness, greenness, L* factor, and the opacity increased and the a* factor decreased. By spraying nano-cellulose on the test samples, most of the optical properties were significantly improved except for the yellowness of the hand-sheet paper. In addition, the most appropriate properties were observed in the paper obtained from DTPA spray and also in the simultaneous spray treatment of DTPA, nano-cellulose, and nano-chitosan on hand-sheet papers. Therefore, it has caused a very sensible increase and improvement in all the optical properties, which can be selected and suggested as the best treatment. The evaluation results of the brightness reversion of the hand-sheet paper from CMP pulp showed that most of the treatments led to a relative reduction of the return of the paper brightness. On the other hand, the lowest and highest brightness return values in the hand-sheet paper were obtained from 0.5% DTPA spray and nano-chitosan spray, respectively. The evaluation results of the SEM images of the test samples compared to the control sample showed that the hand-sheet paper with nano-chitosan and nano-cellulose spray and also in the simultaneous spray treatment of DTPA, nano-cellulose, and nano-chitosan had more favorable surface and structural properties. The existence of less empty spaces (cavity) and more overlap of fibers in the test samples can be a reason for the higher quality of the properties, as well.Conclusion:The results showed that by spraying nanocellulose, nano- chitosan and DTPA on the test samples, the optical properties, brightness, greenness, opacity, a* factor, l* factor , yellowness and brightness durability improved. In addition, among the various treatments, the DTPA treatment in long-term thermal aging and the use of nano-chitosan and nano-cellulose in the short-term aging had noticeable effects on brightness durability and decrease in the color reversion. As a result, there was an increase in the durability of the paper against thermal deterioration.
Eysa Rezazadeh; Ramin Vaysi; Mogtaba Soltani; Abdollah Najafi; S. ESHAGH EBADI
Abstract
This study was aimed to investigate the effect of polyalumium chloride and nano-chitosan on optical and mechanical properties of chemi-mechanical pulp. For this purpose, some of the bleached CMP pulp of Mazandaran Wood and Paper Industries (MWPI) were randomly selected as a control sample. In addition, ...
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This study was aimed to investigate the effect of polyalumium chloride and nano-chitosan on optical and mechanical properties of chemi-mechanical pulp. For this purpose, some of the bleached CMP pulp of Mazandaran Wood and Paper Industries (MWPI) were randomly selected as a control sample. In addition, the polyalumium chloride were used as a white powder at 4 levels of 0, 0.5, 1, and 1.5%. The nano-chitosan was then added to the CMP pulps suspensions at 3 levels of 0, 1, and 2%, as well. Hand-sheets with a basis weight of 60 gr/m2 were prepared from the mentioned pulps. The optical and mechanical properties were then measured and compared using TAPPI standard test methods. The results showed that by adding polyalumium chloride and nano- chitosan(separate) to the CMP pulps, brightness, opacity, greenness,tear, tensile, burst strengths, air resistance increased , but Cobb 60 and a* factor decreased. On the other hand, with the addition of nano-chitosan and polyalumium chloride to CMP pulp, the brightness and greenness increased, but tensile, burst, tear strengths, air resistance, Cobb 60 and opacity low decreased and then suitable increased. Moreover, the findings showed that by simultaneous adding 1% polyalumium chloride and 2% nano-chitosan(separate) and 2% nano-chitosan with 1.5% polyalumium chloride to the CMP pulp, most of the paper properties were improved. Therefore, it can also be introduced as the best treatment.
Ramin Vaysi; Yousef Yousefi-golordi
Abstract
This study was aimed to investigate the effect of cellulose nano-fibers and chitosan on optical and mechanical properties of chemi-mechanical pulp. For this purpose, some of the bleached CMP pulp of Mazandaran Wood and Paper Industries (MWPI) were randomly selected as a control sample. In addition, ...
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This study was aimed to investigate the effect of cellulose nano-fibers and chitosan on optical and mechanical properties of chemi-mechanical pulp. For this purpose, some of the bleached CMP pulp of Mazandaran Wood and Paper Industries (MWPI) were randomly selected as a control sample. In addition, the cellulose nanofibers were used as a white gel at 3 levels of 0, 2, and 3%. The chitosan was then added to the CMP pulps suspensions at 5 levels of 0, 0.5, 1, 1.5, 2%, as well. Hand-sheets with a basis weight of 60 gr/m2 were prepared from the mentioned pulps. The optical and mechanical properties were then measured and compared using TAPPI standard test methods. The results showed that by adding chitosan, tear, tensile, burst and breaking length strengths, air resistance, yellowness, and greenness increased and brightness, Cobb 60 and a* factor decreased. On the other hand, with the addition of chitosan and nano-cellulose to CMP pulp, the tensile, burst, breaking length strengths, air resistance, Cobb 60, yellowness and a* factor increased and the tear, brightness, and opacity decreased. Moreover, the findings showed that by simultaneous adding 2% chitosan, 2% chitosan, and 3% cellulose nanofibers to the CMP pulp, most of the paper properties were improved. Therefore, it can also be introduced as the best treatment.
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 ...
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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).
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 ...
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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
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
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
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
mojtaba goli; Ghasem Asadpur; Saeed Mahdavi; Abdollah Barimani
Abstract
Importing of wood is a solution to supplying raw material in the Iranian paper industry because of wood shortage. Therefore, the effect of mixing the imported aspen roundwood with the two hardwood native forest species including hornbeam and beech were perused on the optical and mechanical properties ...
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Importing of wood is a solution to supplying raw material in the Iranian paper industry because of wood shortage. Therefore, the effect of mixing the imported aspen roundwood with the two hardwood native forest species including hornbeam and beech were perused on the optical and mechanical properties of CMP pulp. Cooking constant conditions consist of maximum temperature were 170 °C with a liquor-to-wood ratio (L/W) of 7, and chemical content of 20% based on the oven-dry weight of the wood chips. CMP pulps were prepared at different cooking times of 30 to 120 minutes using 20, 30, 40, 60, and 100% aspen wood in combination with the two species to achieve the yield of nearly 85%. Standard laboratory handsheets were made after pulp refining by 300 ml CSF, and then the strengths and optical properties were measured. Statistical analysis of result showed that there were significant differences among of the properties of CMP pulps by increasing the aspen wood ratio. All the properties have been improved except opacity paper. The required strength of newsprint and printing/writing paper made in Mazandaran wood and paper industries (MWPI) could be achieved by mixing of 20 and 30% imported aspen wood to the native species used in currently, respectively.
Pulp and paper
Ramin Veisi
Abstract
This research and aim was using Bamboo and Reed CMP pulp for newsprint production. For this purpose, some chips of bamboo stem in the west of Mazandaran were randomly chosen. Then CMP Pulps were prepared at the yield 85%in 120 minutes(Bamboo) and 31 minutes(Reed), by using cooking conditions of Wood ...
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This research and aim was using Bamboo and Reed CMP pulp for newsprint production. For this purpose, some chips of bamboo stem in the west of Mazandaran were randomly chosen. Then CMP Pulps were prepared at the yield 85%in 120 minutes(Bamboo) and 31 minutes(Reed), by using cooking conditions of Wood and Paper Industries of Mazandaran 60 gr/m2 newsprint handsheets were prepared from the Bamboo and Reed CMP and Mill(MWPI) CMP pulps, first in a separate and then mixed way with 25,50,75 percents. Then the optical and mechanical properties were measured and compared according by using TAPPI Standard test methods. The results showed that the most strength of the burst, breaking length, tensile, tear strength, yellowness and opacity were in the handsheets obtained from 100% the bamboo CMP pulp and the lowest strength (except brightness) was in Reed CMP pulp. The results also pointed out that the above-mentioned all strengths (except brightness) can be improved by using 25-100% of the bamboo CMP pulp, too. The results also indicated that 25-100% of the bamboo CMP pulp and 25% of the Reed CMP pulp can use for newsprint production.
Pulp and paper
Afshin Veisi; Saeed Mahdavi; Mohammad Talaeipoor
Abstract
In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals ...
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In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals charge and 10:1 cooking liquor and straw ratio. The yield after defibration treatment varied between 56.5% and 72.5%. Two optimum pulps bleached by TCF method applying 2% and 3% NaOH, 1.5% and 2% H2O2, and 60 and 120 minutes bleaching time. One way analysis variance method showed that bleaching time had the most significant effect on optical properties of handsheet. Applying 3% (based on oven dry weight of the unbleached pulp) NaOH, 2% H2O2, and 120 min. in bleaching improved the brightness and opacity to 52.9%, and 79.5% ISO, respectively. Optimum pulp strengths including tensile, burst and tear indices were measured 43.87 Nm/g, 2.18 kPa.m2/g, and 8.46 mN.m2/g, respectively. All the strengths were higher than newsprint paper strength produced by Mazandaran wood and paper and Korean companies.
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 ...
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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
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 ...
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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.
Somayeh Ghasemi; Rabie Behroz
Abstract
Using high consistency pulp especially in bleaching plant is highly attractive due to considerable reduction in energy and water consumptions and low effluent volume. This research investigates the effect of consistency CMP pulp on bleaching by hydrogen peroxide. For this purpose, unbleached mixed hardwood ...
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Using high consistency pulp especially in bleaching plant is highly attractive due to considerable reduction in energy and water consumptions and low effluent volume. This research investigates the effect of consistency CMP pulp on bleaching by hydrogen peroxide. For this purpose, unbleached mixed hardwood CMP pulp of Mazandaran wood and paper CO. mill was used. Bleaching was carried out with QP sequences. Pretreatment or Q stage was carried out by DTPA as a chelating agent for removing transition metals. Chelating stage had a similar condition for all pulps. bleaching with hydrogen peroxide was carried out in three levels of hydrogen peroxide 2, 3, 4% and proportion NaOH to H2O2: 0.8, 0.7, 0.6 by adding 3% sodium silicate in 70˚C and 150min at four consistency level (10, 15, 25 and 30%). After bleaching, handsheets were made with grammage 60gr/m2 from bleached pulp. The experimental results showed that high brightness and opacity and lower yellowness was obtained at 30% consistency by 2 and 3% peroxide charge. However, by using 4% hydrogen peroxide, higher brightness and lower yellowness attained at 25% consistency. Brightness is increased continuously by increasing consistency from 10 to 30% at 2, 3% peroxide. But at 4% peroxide charge, brightness is increased from 10, 15 and 25%, and then at 30% consistency is decreased significantly. Also under conditioning of 2% peroxide and 30% consistency and 2% peroxide at 25% consistency can obtain similar brightness to 3% peroxide and 25% consistency and 4% peroxide at 10% consistency. That it means of 25, 30% decrease in consumption peroxide and sodium hydroxide.
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 ...
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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
Amir mohsen Nazeri; Mohammad Talaeipoor; Seeyed Ahmad Mirshokraie
Abstract
The present study deals with effects of CMP fines on optical and physical properties of newsprint papers, for which, different batches for CMP fines (0%, 10%. 20%. 30%) of totally 80% pulp is taken, Where the remaining 20% of imported long fiber pulp was taken as fixed amount .
The study ...
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The present study deals with effects of CMP fines on optical and physical properties of newsprint papers, for which, different batches for CMP fines (0%, 10%. 20%. 30%) of totally 80% pulp is taken, Where the remaining 20% of imported long fiber pulp was taken as fixed amount .
The study focused on surving the effects of CMP fines on optical and physical properties of newsprint paper ,after mixing the pulps and making the handsheets .
Generally, the results show the increase in CMP fine amount lead to increase ,Air Resistance and Opacity and decrease Caliper and Roughness, Also that changes in CMP fines has no effect on Brightness .
