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% ...
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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.
Pulp and paper
Amir hooman Hamasi; Mehdi Sabor; Mohammad Talaeipoor; Mohammad Azadfallah
Abstract
The aim of present study was to investigate the effects of xylanase enzyme obtained from Trichoderma viride on APMP pulp from Populus nigra wood. Treatment temperature, time, enzyme dosage and pulp consistency were varied. The results demonstrated that treating by xylanase has considerable effects on ...
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The aim of present study was to investigate the effects of xylanase enzyme obtained from Trichoderma viride on APMP pulp from Populus nigra wood. Treatment temperature, time, enzyme dosage and pulp consistency were varied. The results demonstrated that treating by xylanase has considerable effects on pulp. Paper brightness improved in average 2.5% ISO and the highest gain was 4.5%. Also, using enzyme resulted in enhancement of tear and burst indices. Breaking length of paper from enzyme treated pulp was increased to 4098 meters. Further treatment by xylanase reduced the pulp yield by 2.78% as compared to sample without enzyme treatment. The impact of other treatment such as washing by distilled water and alkaline extraction revealed that these treatments did not have significantly effect on the results of enzyme treatment. The optimum temperature, time, enzyme dosage and pulp consistency were 40-50° C, 70 minutes, 10 U/g of oven dried pulp and 10% respectively.
Pulp and paper
Amir mohsen Nazry; Mohammad Talaeipoor; Saeed Mahdavi
Abstract
The effects of different fines with different shape and size of mechanical Pulp on Paper Properties in two fractions was investigated. Fines was classified in two categories including fibrils and flakes , and then effect of these particles on pulp properties was studied.The fibril fraction was consist ...
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The effects of different fines with different shape and size of mechanical Pulp on Paper Properties in two fractions was investigated. Fines was classified in two categories including fibrils and flakes , and then effect of these particles on pulp properties was studied.The fibril fraction was consist of fibrillar material, i.e., ribbons, fibrils, and thin lamella particles. The flake fraction consist of flake like material i.e., fiber wall fragments and thick lamella. An advanced image analysis method was used to characterize the properties of fibrils and flakes. The results indicate that the fibrils and flake fractions have distinct characteristics and effect on sheet properties. The fibrils strongly affected the strength properties, while the flakes improved light scattering. Generally, the smaller size Particles afforded higher sheet density and strength. Fines content and fibrillar material are very important parameters in mechanical pulping and can also affect quality controlling of mechanical pulp and papermaking.
Pulp and paper
Maryam Rostaei; Rabi Behroz; Saeid Mahdavi
Abstract
This research was performed to improve the properties of the pulp made of Aspen Deltoides, using antraquinone(AQ) catalizer. Neutral sulfite semichemical (NSSC) method in three efficiency levels of 55, 60, and 65% was applied. Cooking situations was selected as: Specific Temperature (175˚ C) , Time ...
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This research was performed to improve the properties of the pulp made of Aspen Deltoides, using antraquinone(AQ) catalizer. Neutral sulfite semichemical (NSSC) method in three efficiency levels of 55, 60, and 65% was applied. Cooking situations was selected as: Specific Temperature (175˚ C) , Time (Variable) , Specific Percentage of Chemicals 14% and Anthraquinone 0.1% . In all stages of cooking, weight ratio of sodium sulfide to sodium bicarbonate was set as 4.5/1. The ratio of cooking liquid to chips was 5/1. The results indicated that AQ causes an increase in efficiency and a significant decrease in Kappa. Researches also indicated that by the use of AQ, strength indexes of the paper such as strength of burst, tearing, tensile, Ring Crush Test and Corrugating Medium Test increases. Optical experiments on hand sheets following addition of AQ, indicated increase in brightness and decrease in opacity.
Pulp and paper
Ahmad Jahan latibari
Abstract
In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping ...
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In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping temperature were used. After digester yield varied between 64.65 and 71.7% and the total yield after defibration was measured as 54.45% and 62%. Unrefined pulp freeness varied between 708 and 765 ml CSF. Pulps produced applying 10-16% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected from further evaluation. These pulps were refined to about 365 ml CSF in a PFI mill and then handsheets were made for strength evaluation. The apparent density of the handsheets varied between 437-488 kg/m3, tear index between 6.51-7.11 mN.m2/g, and tensile index between 29.2 -30.8 N.m/g. Significant difference at 99% was not observed between the strength of the pulps. Then pulp produced applying 10% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected for bleaching trials. Totally Chlorine Free (TCF) bleaching sequence was used for bleaching the selected pulp. Pulps bleached applying 4% H2O2 and 3.5% NaOH, 3% sodium Silicate, 0.5% MgSO4 and 0.3% DTPA for 2 hours showed the highest brightness of 50.69% compared to 29.2% for unbleached pulp.
Pulp and paper
Somayeh Solimani; Sayed javad Sepidehdam; Hamid Malkian
Abstract
The stability of colored paper through dyes is very important in manuscript restoration. In this project Japanese papers (model papers) were colored with different dyes such as henna, walnut and tea. Artificial aging test was performed on these papers as well. Dye effect on stability of colored papers ...
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The stability of colored paper through dyes is very important in manuscript restoration. In this project Japanese papers (model papers) were colored with different dyes such as henna, walnut and tea. Artificial aging test was performed on these papers as well. Dye effect on stability of colored papers was measured through mechanical (folding endurance, tensile breaking and tear resistance) tests before/after aging test statistically; folding endurance test results in color level is significant. Tea colored paper sample was not as stable as model paper in folding resistance and the average of tea sample compare to model sample was 39.9 to 69.5. Folding endurance reduction was seen in tea and henna samples following aging test. The effects on tensile and tear resistance were not statistically different or dyes were not affected to cause any increase or decrease in stabilities. Scanning electron microscopy (SEM) images of model and dyed papers have demonstrated color and aging effects. The pH test upon henna sample, have shown acidic condition. Model paper was not the same as dyed papers in terms of weight and thickness. All samples include model and dyed papers, demonstrated decrease in brightness and yellowness and increase in redness following aging test.
Pulp and paper
Hamd Unesi kord khalili; Mehran Jalilvand; Rabi Behroz
Abstract
The purpose of this study was to investigate effects of different loading levels and addition of urea formaldehyde and polyethylene on the creep behavior of composites made from wastes of OCC recycling mills. The composites manufactured by hot press method and three-point ...
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The purpose of this study was to investigate effects of different loading levels and addition of urea formaldehyde and polyethylene on the creep behavior of composites made from wastes of OCC recycling mills. The composites manufactured by hot press method and three-point bending test performed before creep test. In general, the results showed positive effects of additive materials such as urea formaldehyde and polyethylene on the creep behavior of the composites. While adding UF and PE decreased primary and final creep as well as return deformation percentage of the composites. Also the obtained results indicated that remaining creep had higher sensitivity to loading levels compared to primary and final creep. Also the increase of the load levels from 20% to 30% led to an increase in creep content of the composites.
Pulp and paper
Ahmad Samariha; Jafar Ebrahim poor tasmani; Alireza Khakifiroz
Abstract
This research was performed to investigate the properties of CMP pulp from rape straw. Samples of Colza straw was prepared from a farm located in the vicinity of Babul. Chemo mechanical Pulping process was employed using the 20 % cooking liquor of Mazandaran pulp and paper mill (Sodium Sulphite) based ...
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This research was performed to investigate the properties of CMP pulp from rape straw. Samples of Colza straw was prepared from a farm located in the vicinity of Babul. Chemo mechanical Pulping process was employed using the 20 % cooking liquor of Mazandaran pulp and paper mill (Sodium Sulphite) based on the dry weight of colza straw. Cooking time and temperature were adjusted at 30, 40 and 50 minute and 170 degree centigrade, respectively. Pulps were refined up to 300± 25 CSF by using PFI Mill refiner and 60 g/m2 hand sheets were made from each sample of pulps. The strength indices of hand sheets were measured using TAPPI standards. The results showed that strength indices like Tensile strength, Tear strength, Burst strength, Breaking length and Stiffness increased as the pulp yield decreased.
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 ...
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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
Rabi Behroz; Hamed Unsi kord khelili; Saeid Kazemi najafi
Abstract
Effect of Kraft lignin as a compatibilizer on the short-term water absorption (2 and 24 hours) and mechanical properties of wood flour-polypropylene composites was studied. The black liquor of Chooka pulp and paper mill was acidified and Kraft lignin was extracted by precipitation. The extracted ...
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Effect of Kraft lignin as a compatibilizer on the short-term water absorption (2 and 24 hours) and mechanical properties of wood flour-polypropylene composites was studied. The black liquor of Chooka pulp and paper mill was acidified and Kraft lignin was extracted by precipitation. The extracted lignin at three levels of 2, 5 and 10 percent was mixed with wood flour by physical mixing method. All materials used were oven-dried. Wood flour, lignin and PP with or without MAPP were used to produce composites by flat hot press method. The results of this study indicated that generally lignin improved physical (short term water absorption) and mechanical properties (flexural modulus, flexural strength and impact strength). The bending test result showed that without MAPP, the composites with 2 and 10 percent lignin exhibited higher flexural modulus and strength, respectively. But at the presence of compatibilizer, the composites with 5 percent lignin exhibited the highest flexural modulus and strength. The composite with 2 percent of lignin exhibited higher flexural modulus and short-term water absorption rather than the composites with 2% MAPP. This result indicated positive effect of lignin in the composites. Also the composites with 10 percent lignin exhibited the highest impact strength and short-term water absorption. But there were no significant difference between the impact strength of composites with 5 and 10 percent lignin.
Pulp and paper
Babak Mirzaei; Kazem Dos hosseini; Esmaeil Ghasemi; Yahya Hamzeh
Abstract
In this study two types of paper sludge, prepared by Mazandaran wood and paper company and Latif papermaking company along with wood flour utilized as plastic filler in polypropylene and high density polyethylene based composites. Weight percentage ratio of coupling agent, polymer and filler were kept ...
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In this study two types of paper sludge, prepared by Mazandaran wood and paper company and Latif papermaking company along with wood flour utilized as plastic filler in polypropylene and high density polyethylene based composites. Weight percentage ratio of coupling agent, polymer and filler were kept constant 2%, 38%, and 60% in all formulations, respectively and composites were prepared by varied ratios of paper sludge and wood flour include 0: 60, 40: 20, 20: 40, and 60:0. Density, water absorption and thickness swelling of injection molded composites then measured. The results indicated the gradual substitution of wood flour by paper sludge increases the density of composites, and improves their water absorption and thickness swelling. The ratio of paper sludge to wood flour had statistically significant difference on all these properties, but the paper sludge type showed statistical difference just on the density of composites. Further to that, polypropylene based composites demonstrated lower density, water absorption and thickness swelling compared to high density polyethylene based ones.
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.
Pulp and paper
Davod Efhami; Mohammad reza Dehghani
Abstract
In this work effect of initial alkali charge were investigated on the yield and kappa number of soda beech pulp and alkali consumption pattern. The results indicated that, the regression models are useful for studying the relations between yield, kappa number and alkali consumption. Soda cooking was ...
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In this work effect of initial alkali charge were investigated on the yield and kappa number of soda beech pulp and alkali consumption pattern. The results indicated that, the regression models are useful for studying the relations between yield, kappa number and alkali consumption. Soda cooking was performed in 30, 40, 50, 60 and 70 gr.lit-1 initial alkali concentration and five different cooking times. The chips dimensions were in the range of 3-5 cm length, 1-2 cm width and 0.05 cm thickness. The results showed that increasing of alkali charge decreased the time of cooking in the same yield or kappa number. Deligninifaction decreased significantly in kappa number lower than 30. In the same kappa number, increased alkali charge gave a lower yield. The alkali consumption was regularly decreased with increasing of initial alkali charge from 30 to 70 gr/lit, but alkali charge consumption pattern varied in less and more than 30 kappa numbers.
Pulp and paper
Mohammad ali Azad far; Rabie Behroz; Ahmad Jahan - Latibari
Abstract
The influence of oxygen delignification as an environmental friendly process, was investigated on Soda/AQ pulp from Old Corrugated Container (OCC) fibers. Oxygen delignification at four levels of alkali (2, 3, 4 and 6% based on OD weight of pulp) has been applied and the optimum alkalinity to reach optimum ...
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The influence of oxygen delignification as an environmental friendly process, was investigated on Soda/AQ pulp from Old Corrugated Container (OCC) fibers. Oxygen delignification at four levels of alkali (2, 3, 4 and 6% based on OD weight of pulp) has been applied and the optimum alkalinity to reach optimum Kappa no, yield and brightness, opacity and strength based on 60 g/m2 hand sheets were determined. The results indicated that application of oxygen delignification marginally reduced the opacity of the pulp. Tear strength increased where as tensile and burst strength decreased. Based on the comparison of the data from oxygen delignified pulp, it is concluded that oxygen can be utilized to improve the properties of soda-AQ pulp from OCC prepared for bleaching step. Carbohydrates are preserved while removing lignin. Normalized equations revealed that oxygen delignification at 3% alkali produced the best results.
Pulp and paper
Yahya Hamzeh; Babak Mirzaei; Kazem Dost hosseini; Alireza Ashori; Kambiz Rashedi; Alyeh olfat
Abstract
Characteristics of pulp and paper mill solid wastes depend generally on the raw materials, stock preparation process as well as wastewater treatment plant. In order to determine the best application of paper mill solid wastes, physicochemical properties of solid waste produced in the Mazandaran Wood ...
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Characteristics of pulp and paper mill solid wastes depend generally on the raw materials, stock preparation process as well as wastewater treatment plant. In order to determine the best application of paper mill solid wastes, physicochemical properties of solid waste produced in the Mazandaran Wood and Paper Industry Co. and Latif Paper Co. were analyzed. The dry content, pH, fiber dimensions, composition of organic and inorganic compounds of the both solid were analyzed. The dry content of the produced wastes in Latif and Mazandran were determined as 69.3 and 36.7 percent, respectively. The pH of both wastes was close to neutral (pH/7.0). The fiber length of Latif and Mazandaran wastes were 1.68 and 1.08 mm, respectively. In addition, the total amount of carbohydrates, glucose and mannose quantity in the Latif waste were determined as 48.09, 29.5 and 7.2 percent that were higher than that of Mazandaran waste. In the contrary, the lignin, xylose and galactose content of Mazandaran waste were determined as 15.3, 17.3 and 3.7 percent that were higher than those of Latif waste. The mineral content of Latif and Mazandarn wastes were determined 44.7 and 39.5 percent, respectively. XRF analyses revealed that the predominant elements in the incinerated ash of both wastes contained calcium oxide, aluminum oxide and silicon oxidethat can be used as raw material for lightweight concrete and zeolite synthesis.
Pulp and paper
Reza Hosseinpoor; Ahmad Jahan - Latibari; Ajang Tajdini; Sayed javad Sapideh dam; Ramin Farnod
Abstract
The impact of chemical treatment variables including treatment time and temperature, chemical charge as well as pulp freeness on fiber quality of Colza stem chemi-mechanical pulp was studied using Fiber Quality Analyzer (FQA). Three treatment times (15, 30 and 45 minutes), two treatment temperatures ...
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The impact of chemical treatment variables including treatment time and temperature, chemical charge as well as pulp freeness on fiber quality of Colza stem chemi-mechanical pulp was studied using Fiber Quality Analyzer (FQA). Three treatment times (15, 30 and 45 minutes), two treatment temperatures (125 and 145 °C), two chemical charges (4% NaOH + 8% Na2SO3 and 8% NaOH +12% Na2SO3) as well as pulp refining were evaluated. The results revealed that at higher values of treatment variables, fiber average length was reduced and varied between 0.49 and 0.65 mm. However, the influence of pulp refining on fiber average length was not very pronounced. Pulps contained between 55 -63 % fines, which is on the high range and refining increased the fine content by 5%. Fiber coarseness varied between 10 and 41 mg/100m which was raised to 14 and 53 mg/100m upon refining. Even though refining did not alter fiber curl, but fiber kinks were increased.
Pulp and paper
Abas Fakhryan; Fardad Golbabaei; Mohammad mehdi Brazandeh
Abstract
In this research pulp and paper making characteristics of Sequoia sempervirens from Chamestan noor research station were studied. The dry and critical specific gravity of sap wood 0.352 and 0.324, heart wood 0.43 and 0.40, fiber length 2.01 mm. diameter 39.84µm. lumen 33.15µm and cell thickness ...
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In this research pulp and paper making characteristics of Sequoia sempervirens from Chamestan noor research station were studied. The dry and critical specific gravity of sap wood 0.352 and 0.324, heart wood 0.43 and 0.40, fiber length 2.01 mm. diameter 39.84µm. lumen 33.15µm and cell thickness wall 2.89µm were measured as respectively. The amount of cellulose of 52.63%, lignin 35.32%, ext. 6.68% and ash 0.45% were obtained as well. Kraft process was used for pulping. The yield of these pulps in 12% effective alkali were measured as 56% and in 18% effective alkali 39.69% respectively. In 3 hours of cooking time, the tear strength of these pulps 19.74 mNm2/gr and In 2 hours of cooking time 15.22 mNm2/gr respectively were measured.
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
Saeid Kamrani; Ahmad reza Saraeyan; Eyman Akbarpoor
Abstract
In this study, mechanical and optical properties of CMP, one stage APMP and two stage APMP pulps ( from Tajan wheat straw Golestan province ) were investigated. wheat straw collected at research center of Agriculture and Natural resources of Golestan province. Fiber dimensions such as average fiber length ...
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In this study, mechanical and optical properties of CMP, one stage APMP and two stage APMP pulps ( from Tajan wheat straw Golestan province ) were investigated. wheat straw collected at research center of Agriculture and Natural resources of Golestan province. Fiber dimensions such as average fiber length , diameter cell , lumen and fiber wall thickness were assessed at 1.18mm, 18.156, 11.461 and 3.396 microns, respectively. chemical components such as cellulose , lignin , ash and extractives were assessed at 53.7, 21.1, 5.1 and 8.5 percent, respectively. Based on the preliminary experiment results, impregnation temperature was 950C, impregnation times of 10, 20, 30, 40 minutes, caustic charge 10% and peroxide charge was 3% in CMP ,one stage APMP and two stages APMP pulps. Considering pulp properties and treatment conditions, many treatments including 20 and 40 minutes treatments were selected for making of handsheet. The selected pulps were refined up to 350 ml (CSF) freeness prior to making of hasndsheet. Final results indicated that two stages APMP pulp (impregnation in time 40 minutes) had the highest burst strength, breaking length and brightness. Also, the results of yield and tear strength showed that, there was no meaningful difference at the 5% level between three methods CMP, one and two stages of APMP pulps.
Pulp and paper
Pyvand Darabi; Hamideh Abdolzadeh; Ali naghi Karimi; Seeyed Ahmad Mirshokraie; Kazem Doosthoseini
Abstract
In this study capability of acetylated poplar flour in manufacture of high density poly ethylene composite which expose to accelerated weathering, was investigated. The acetylation degrees at medium and zero (control) levels, use of anti- oxidant and duration of weathering were considered as variables ...
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In this study capability of acetylated poplar flour in manufacture of high density poly ethylene composite which expose to accelerated weathering, was investigated. The acetylation degrees at medium and zero (control) levels, use of anti- oxidant and duration of weathering were considered as variables and their effects on discoloration and photodegradation of WPC were investigated. To determine treatments influence on changes and color fade resulting from weathering, samples were tested after o, 250, 2000 hours of weathering. The results indicated that application of acetylated wood flour in WPC can reduce about 25% of weathering discoloration in short time and about 17% in long time. Also it shows that as exposed time of weathering increase Anti oxidant loss its effect. Although in short time it can reduce 12% of weathering color changes. FTIR results show that after 2000 h of weathering all peaks samples had same decrease which mean none of the treatments were useful. But Anti oxidant can reduce depth of weathering.
Pulp and paper
Mohammad Molaei; Aliakbar Enayati; Yahya Hamzeh; Maryam Rostaei
Abstract
A fundamental study was carried out to explore the canola stalks properties in order to increase the use of abundant agricultural residuals in pulp and paper production. In this study, the morphological, chemical composition and soda pulping properties of Canola stalks were investigated. The results ...
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A fundamental study was carried out to explore the canola stalks properties in order to increase the use of abundant agricultural residuals in pulp and paper production. In this study, the morphological, chemical composition and soda pulping properties of Canola stalks were investigated. The results showed that except the thicker cell wall, the morphological properties of Canola stalks fibers were comparable to those of nonwoods and hardwoods fibers. Chemical analysis indicated that Canola stalks contains lower amount of cellulose (44%), while the lignin, hemicelluloses and ash content of Canola stalks are comparable to other non-woods. In comparison with most of non wood fiber resources, soda pulping of Canola stalks required higher chemical charge and pulping time. Soda pulping of Canola stalks in 22% active alkaline and 100 min in max temperature produced pulp with 82.6% ISO of brightness The strength properties of bleached Canola stalks soda pulp include tensile index (Nm/g), burst index (kpam2/g) & tear index (mNm2/g) showed respectively 63.6, 2.22 & 4.9.
Pulp and paper
Mohammad Ahmadi; Mohammad mehdi Faezipoor; Ahmad Jahan latibari; Sahab Hejazi
Abstract
Neutral sulfite semi chemical pulping of Canola residues has been investigated. Canola residues collected from research farm at Agriculture and Natural Resources, University of Tehran, in Karaj. Chemical composition of Canola residues including cellulose, lignin, extractives soluble in ethanol-acetone ...
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Neutral sulfite semi chemical pulping of Canola residues has been investigated. Canola residues collected from research farm at Agriculture and Natural Resources, University of Tehran, in Karaj. Chemical composition of Canola residues including cellulose, lignin, extractives soluble in ethanol-acetone and ash were determined using relevant TAPPI standard test methods. Fiber dimensions of Canola residues were also measured. Then neutral sulfite semi chemical pulps were produced from Canola residues applying following conditions: Cooking time at 3 levels(20,40,60min),chemical charge at 5 levels(8,10,12,14,16 %), Cooking temperature was kept constant for all cooks at 175ċ , Na2SO3 to Na2CO3 ratio was 3:1,and liquor to Canola residues at 8:1. Each pulping was repeated tree times. At the end of each cooking, initial defibration was carried out using a laboratory disc refiner. Total yield before defibration and yield after defibration and screened yield were determined. The highest yield (72%) was obtained at treatment combination of and the lowest yield (58.7%) was in treatment of .Both factors, time and chemical charge, had significant effect on yield and increasing these two factors caused lower yield.
Pulp and paper
Somayeh Ghasemi; Ahmad reza Saraeyan
Abstract
Comparative study of pulp yield of sap wood and heart wood of Populus deltoides under both Kraft and soda cooking process have been showed that the heart wood pulp has a lower yield than that of sap wood pulp. Yield of heart wood and sap wood soda pulps was 4 percentages higher than Kraft pulp. Contrary ...
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Comparative study of pulp yield of sap wood and heart wood of Populus deltoides under both Kraft and soda cooking process have been showed that the heart wood pulp has a lower yield than that of sap wood pulp. Yield of heart wood and sap wood soda pulps was 4 percentages higher than Kraft pulp. Contrary to yield, residual lignin content (Kappa number) is more in heart wood pulp than sap wood pulp in both processes. Kappa numbers of heart wood and sap wood Kraft pulps were about 34% lower than soda pulps. The results showed that in spite of lower yield of heart wood than sap wood, the residual lignin of heart wood pulp was more than sap wood pulp. The higher delignification efficiency of Kraft cooking is related to cooking liquor compositions, especially Na2S
Pulp and paper
Abbas Fakhryan roghani; Fardad Golbabaei; Hossein Hosseinkhani; Kamyar Salehi; Saeed Mahdavi; Sabrineh Mohsseni tavakoli
Abstract
In this reseach, chemical, anatomical and pulping properties of 12 years old Populus.triplo of adapting plan and quantity properties of this tree from karaj research station were investigated.The average of fiber length ,diameter ,lumen and thickness of cell wall 1.27 mm ,31.88 um, 23.54 um and 4.22 ...
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In this reseach, chemical, anatomical and pulping properties of 12 years old Populus.triplo of adapting plan and quantity properties of this tree from karaj research station were investigated.The average of fiber length ,diameter ,lumen and thickness of cell wall 1.27 mm ,31.88 um, 23.54 um and 4.22 um and cellulose ,lignin , Ext. and ash %53.74 , %22.87 , %1.8 and %1.5 were measured respectively.The yield and kappa number of pulps between 41.152% - 48% and 18.06 – 25.28 were measured.In 14% and 18% effective alcoholli, tearh index 9.307 mNm²/gr and 10.147 mNm²/gr were obtained.
Pulp and paper
Mohammad Azadfallah; Arezo Noori
Abstract
Yellowing of lignin-rich mechanical pulp is mainly attributed to light-induced changes in lignin structure. Hence, in this study the photodegradation of milled wood lignin (MWL) prepared from hardwood bleached chemimechanical pulp (BCMP) was investigated. The lignin preparation was then impregnated on ...
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Yellowing of lignin-rich mechanical pulp is mainly attributed to light-induced changes in lignin structure. Hence, in this study the photodegradation of milled wood lignin (MWL) prepared from hardwood bleached chemimechanical pulp (BCMP) was investigated. The lignin preparation was then impregnated on Whatman filter paper and irradiated with UV light during 4 hour exposure time. Then, photodegraded lignin was recovered and characterized by 13C-NMR.Irradiation caused to β-O-4 bonds cleavage, increase in carboxylic and phenolic hydroxyl groups, decrease in methoxyl, primary and secondary hydroxyl group. The amount of β-β and β-5 condensation structures was increased during irradiation.
