Pulp and paper
Arman Sadafi Ardejani; Esmaeil Rasooly Garmaroody; Pyam Ghorbannezhad sorkhkolaei
Abstract
Background and purpose: Cellulose fiber has an anionic property to some extent due to having acid groups created during the chemical cooking and pulp bleaching. These acid groups may be carboxylic groups (COOH) which have more activity and reactivity compared to the hydroxyl groups present on the carbohydrates ...
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Background and purpose: Cellulose fiber has an anionic property to some extent due to having acid groups created during the chemical cooking and pulp bleaching. These acid groups may be carboxylic groups (COOH) which have more activity and reactivity compared to the hydroxyl groups present on the carbohydrates of lignocellulosic materials. If it is possible to increase the number of these groups on the fiber surface, it can improve the strength of the final paper. This research was done in order to improve the characteristics of kraft pulp from Chuka pulp and Paper Company by using acid oxidation method with hydrogen peroxide.
Materials and methods: In this research, kraft pulp, which was collected from Chuka Company, was used as a raw material. In this regard, first, kraft pulp were subjected to acid oxidation treatment using hydrogen peroxide the rate of 1, 3, 5 and 10% at 85 °C, in 90 min., pH = 4 and consistency of 2.5%. At the end of this step, the pulps were thoroughly washed with distilled water and used for the next steps. Then the structural characteristics of the fibers such as kappa number, WRV, carboxyl groups, viscosity and FT-IR analysis were evaluated and compared with the control sample of Chuka kraft pulp. SPSS software was used for the statistical analysis of this research and the data were statistically analyzed using the analysis of variance technique. The comparison between different samples and treatments was done based on the grouping of averages and by Duncan's test method at a confidence level of 95%.
Results: The results showed that the oxidized pulps with up to 3% peroxide consumption had the lowest kappa, carboxyl groups and viscosity and the highest WRV. Increasing the consumption of peroxide the rate of greater than 3% has caused an increase in Kappa number, carboxyl groups and viscosity, and instead they have faced with the decrease in WRV. These changes were also confirmed by FT-IR evaluations. The reason for the decrease in kappa number up to 3% concentration is due to the removal of lignin from the fiber wall, and the reason for its increase in concentrations at more than 3% peroxide, is probably due to the creation of acidic hexuronic groups during the oxidation process, which usually cause errors in the measurement of kappa. In addition, the removal of lignin improved the WRV properties of the fibers and further reduced this property. The content of carboxyl groups for both alkaline and acidic conditions seems to be more or less unchanged, which means that in C6, most aldehydes are converted into carboxyl groups, and in C2 and C3, oxidation often causes the formation of ketones. On the other hand, it seems that increasing the carboxyl groups in treatments above 3% has led to an increase in the molecular weight of cellulose, which has increased the viscosity.
Conclusion: The evaluation of the results showed that the oxidation of acidic hydrogen peroxide has modified and improved the characteristics of kraft pulp, and its effects are expected to be positive on the characteristics of the final papers. In this regard, 1% and 3% acid oxidation treatments with hydrogen peroxide seems more suitable for paper production.
Pulp and paper
Omid Esmailiey; Esmaeil Rasooly Garmaroody; Rahman Jafari petroudi
Abstract
Background and purpose: In the production of pulp, materials such as sodium hypochlorite, chlorine dioxide, ozone, hydrogen peroxide, etc. are used in the bleaching process. In addition, the above-mentioned materials can be used as oxidizing materials to increase the surface charge of fibers, can ...
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Background and purpose: In the production of pulp, materials such as sodium hypochlorite, chlorine dioxide, ozone, hydrogen peroxide, etc. are used in the bleaching process. In addition, the above-mentioned materials can be used as oxidizing materials to increase the surface charge of fibers, can help the paper to be more resistant. Therefore, this research was conducted to investigate the effect of fiber oxidation with hydrogen peroxide and sodium hypochlorite on the characteristics of NSSC and OCC pulps as fresh and recycled pulps, respectively.Materials and methods: The pulps required for this research, unbleached NSSC pulp and OCC pulp were obtained from Mazandaran wood and paper factory, and first, the percentage of consistency, initial freeness and brightness of the pulp were measured. Also, the required chemicals were all of industrial grade, hydrogen peroxide (in liquid form 52%) from Chlor Pars Tabriz Company and sodium hypochlorite (in liquid form 16.4%) from Kleran Semnan Company and sodium silicate from Bawand Shimi Qazvin Company, caustic (Liquid soda) with a purity of 47% for bleaching with peroxide was obtained from Arvand Abadan Petrochemical, and soda ash (solid soda) with a purity of 90% for bleaching with hypochlorite was obtained from Chloran Pars, Semnan. In order to control the destructive effects of transition metals, all pulps were treated with 0.2% DTPA, in 2% dryness conditions, time 30 minutes, temperature 90 degrees Celsius and pH=5.5-5, before bleaching. At the end of this step, the pulp is thoroughly washed with distilled water and used for the next steps. For the oxidation of both types of pulp, 3, 4, 5% hydrogen peroxide and sodium hypochlorite were used for oxidation of NSSC pulp using the above ratios (similar to peroxide) and for OCC pulp, 0.5, 1 and 1.5% hypochlorite ratios were used. Then the structural characteristics of the fibers such as pulp freeness, kappa number, WRV, viscosity, carboxyl groups were investigated and finally, the pulps were evaluated by FT-IR spectroscopy.Results: The results showed that with the increase in the consumption of hypochlorite, freeness increased in the oxidized NSSC pulps, but the trend of freeness decreased in the oxidized OCC pulp. This issue shows the situation regarding the use of peroxide. Also, the oxidation of pulp by sodium hypochlorite compared to peroxide has resulted in the release of more lignin, and in this sense, the effectiveness of OCC pulp (with 1.5% hypochlorite, equivalent to 56.68% Kappa loss) has been higher compared to NSSC pulp (with 5% hypochlorite, equivalent to 83.27% Kappa loss).The amount of water retention value in the pulp fibers in the NSSC pulp treatments has increased compared to the control pulp, and in the case of the OCC treatments, it has not changed significantly compared to the control treatment, and only in one case (OC-Na1) has a significant decrease. With the increase of peroxide consumption in the oxidation process of both types of NSSC and OCC pulp, despite the increase in viscosity, there is no significant difference between different consumption levels. In addition, with the increase in the level of hypochlorite consumption, a significant increase in the viscosity of the aforementioned pulps is observed So that the highest increase related to the sample using 5% hypochlorite for NSSC pulps was equal to 731.87 ml/g. The amount of carboxyl groups of pulps treated with peroxide increased in both types of NSSC and OCC pulps compared to the control sample so that the highest amount of carboxyl groups related to 5% treatment was equal to 0.0468 mmol/g for NSSC samples. The evaluation of FT-IR spectroscopy also shows that the oxidation treatment with peroxide and hypochlorite has increased the carboxyl groups on both types of pulp compared to the control samples.Conclusion: The effectiveness of hypochlorite compared to peroxide in the creation of carboxyl groups in both types of pulp was more, which seems that the increase of carboxyl groups on the cellulose chain occurred more on C6 by peroxide and more on C2 and C3 by hypochlorite. The oxidation process increases the viscosity of paper pulp by increasing the carboxyl groups and due to the creation of a higher molecular weight. In addition, the increase of carboxyl groups due to higher chemical activity has made them able to absorb higher water and thus higher WRV.
Jafar Ebrahimpour Kasmani; Ahmad Samariha; Saeed Mahdavi
Abstract
This study was carried out to compare the individual and combined effects of nanolignocelluloses (NLC), cationic polyacrylamide (CPAM), cationic starch (CS) and imported chemical long fiber (LF) in the manufacture of recycle liner and fluting paper for packaging. Individual treatments of OCC were included ...
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This study was carried out to compare the individual and combined effects of nanolignocelluloses (NLC), cationic polyacrylamide (CPAM), cationic starch (CS) and imported chemical long fiber (LF) in the manufacture of recycle liner and fluting paper for packaging. Individual treatments of OCC were included 15% LF, 6% NLC, 1.5% CS and 0.15% CPAM as addetives. Combined treatments were included 6% NLC and 1.5% CS, 6% NLC and 0.15% CPAM. Handsheets were made with grammage of 127 g/m2 by application the mentioned treatments. Finally, the physical, mechanical properties and microscopic structure of handsheet were investigated. The results showed that addition of LF and NLC caused the density of handsheets decreased compared to the control. The individual and combined treatments led to increasing the tensile and burst strength of handsheet. Also, the tear strength of handsheet increased compared to the control except for the combined treatment of NLC and CS. FE-SEM images showed pores relative reduction in handsheet that prepared from combination treatments. It showed negative effect on water drainage. The addition of 6% NLC and 0.15% CPAM to OCC pulp resulted in the highest crush strengths as RCT and CMT compared to the control. SEM micrographs showed relatively reduced pores in handsheets prepared from combined treatments, which could have negative effect on the dewatering of OCC pulp.
Pulp and paper
Noradin Nazaneghad; seid najeh Mosavi; Seid Majid Zabihzadeh
Abstract
Abstract The aim of this study is investigate the effect of Tapioca and Corn cationic starch on the mechanical characteristics of paper from old corrugated containers. The paper recycling decrease its properties and affected on the paper quality. For promoting these fibers may be effective the use of ...
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Abstract The aim of this study is investigate the effect of Tapioca and Corn cationic starch on the mechanical characteristics of paper from old corrugated containers. The paper recycling decrease its properties and affected on the paper quality. For promoting these fibers may be effective the use of different treatments. Cationic starch is effective treatment for recycled fibers Promotion. In this study, the cationic starch of Tapioca and Corn, each at three different levels 0.5, 1 and 1.5 % and comparison with samples (without cationic stretch). Hand sheets with a grammag of 120 g/m2 were made and their strength properties were measured. As well as, the absorption rates of two kinds of starch on the pulp were calculated using the Acid- Phenol method. The results indicated that the use of 1.5% of Tapioca starch and 1% Corn starch had an optimum effect in increasing the strength of the produced paper. Concerning the comparison of these different types of starch, the tapioca starch was more effective than the corn starch.
Sina Modirahmati; Ahmad Jahan Latibari; Amir Nourbakhsh; Mehran Roohnia; Mansor Minaei
Abstract
The impact of nanoclay addition on the properties of polypropylene/ OCC fibers/ nanoclay Composite was investigated. Composites were prepared using 67% polypropylene, 30% OCC fiber, 3% MAPP and three dosages (2.5, 5, 7.5% based on total weight of PP/OCC/MAPP) of nanoclay. Premix- ...
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The impact of nanoclay addition on the properties of polypropylene/ OCC fibers/ nanoclay Composite was investigated. Composites were prepared using 67% polypropylene, 30% OCC fiber, 3% MAPP and three dosages (2.5, 5, 7.5% based on total weight of PP/OCC/MAPP) of nanoclay. Premix- melting of nanoclay and polypropylene was used to add nanoclay to the composite mixture. Pre-mixed nanoclay/ polypropylene was melt-mixed with OCC fibers and MAPP and then test samples were made using this compound. The results revealed that addition of nanoclay to polypropylene/OCC fiber composite reduced flexural strength , tensile strength and notched Izod impact strength, but the flexural modulus and tensile modulus of final composite were improved significantly. The influence of nanoclay addition on flexural strength and tensile modulus of composite was statistically significant at 99% level whereas its effect on tensile strength was statistically significant at 95%. However, the effect of nanoclay on both flexural modulus of elasticity and impact strength was not statistically significant. The addition of nanoclay to the composite reduces the bonding between polypropylene and OCC fibers. In the case of notched Izod strength, nanoclay particles generated stress concentration point within the composite structure initiating easier failure. Water absorption after 2 and 24 hours immersion was reduced.
Sasan َAbangah; Ahmad Jahan Latibari; Seyad Javad Sepideh dam; Mehran Roohnia; Mohammad ali Hossein
Abstract
The influence of reinforcing fibers (old corrugated container fibers called OCC) and addition of foaming agents (Azodicarbinamide and sodium bicarbonate) on density, strength properties and dimensional stability of OCC fiber/polypropylene composite were investigated. Conten of reinforcing fibers constant ...
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The influence of reinforcing fibers (old corrugated container fibers called OCC) and addition of foaming agents (Azodicarbinamide and sodium bicarbonate) on density, strength properties and dimensional stability of OCC fiber/polypropylene composite were investigated. Conten of reinforcing fibers constant at 20% and the content of either foaming agent varied as 3, 5 and 7%. Strength properties including MOR, MOE, maximum tensile strength and modulus as well as izod impact strength were measured. Water absorption after 2 and 24 hours soaking in distilled water at 23±2 ºC were measured. Foaming agent decomposition caused some chemical residues in composite and the diffusion and penetration of polymer into the fibers structure led to increase in the density from 839.2 kg/m3 for pure polypropylene to 919.2 - 947.9kg/m3 for the composite, MOR and MOE also increased by the addition of foaming agent and the reinforcing fiber. The effect of 5 or 7% sodium bicarbonate was statistically significant and it improved the properties of the composite. Similar results were obtained for tensile strength and the modulus. Reinforcing fibers and foaming agent caused higher impact strength of the composite. Water absorption of the composites was higher than pure polypropylene.
Chemistry of wood
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.
