Pulp and paper
Zahra Razmpour; ghasemg asadpour; kermanian hossein; omid ramezani; Seyed Majid Zabihzadeh
Abstract
Efficient approaches to eliminate or neutralize stickies is one of the topics of recent research. In the current study, some of the most conventional chemical and physical strategies in controlling these contaminants were compared. Control of micro-stickies originated from recycling of OCC using some ...
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Efficient approaches to eliminate or neutralize stickies is one of the topics of recent research. In the current study, some of the most conventional chemical and physical strategies in controlling these contaminants were compared. Control of micro-stickies originated from recycling of OCC using some selected physical approaches (washing, washing-flotation, flotation-washing and flotation) and some selected chemical methods by 4 fixing agents (Alum-PAC-pDADMAC-Cationic Starch) at 0.1-0.5-1 % dosing levels based on oven-dry weight of pulp were investigated. Electrical conductivity, TDS, turbidity, dissolved and colloidal substances (DCS) and COD were measured and compared to evaluate the efficiency of each approaches of micro- stickies removal. The results indicated that the lowest value of electrical conductivity and TDS in the physical methods was related to the flotation-washing stage and in the chemical methods was related to cationic starch 1%. The lowest amount of turbidity in the physical methods was observed in the washing and washing-flotation. Besides, the potential of secondary stickies was the lowest in the washing stage, while the flotation method had the highest potential of secondary stickies. Among the different dosing levels of the fixing agents, the lowest level of turbidity and DCS was determined for pDADMAC with 0.1% addition level, and the lowest amount of potential of secondary stickies was observed for Alum with 0.5% dosage. Both in the physical and chemical methods turbidity and DCS in pH4 was more than neutral pH. In the chemical approach with cationic starch dosage at 1% and in the physical method with the washing-flotation stage, the lowest amount of COD was reached
Composite wood products
Mohammad Ahmadi; Bita Moezzipour; mearaj sharari
Abstract
In this study properties of fibers recycled from MDF wastes as one of the potential important resources as raw materials for MDF production were investigated. For this purpose, two different methods including ohmic heating (for 2 and 4 min) and hydrothermal method (at 105˚c for 150 min) were utilized ...
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In this study properties of fibers recycled from MDF wastes as one of the potential important resources as raw materials for MDF production were investigated. For this purpose, two different methods including ohmic heating (for 2 and 4 min) and hydrothermal method (at 105˚c for 150 min) were utilized for recycling the wastes of MDF and original fibers were studied as control sample. The chemical composition of fibers (lignin, cellulose and hemicellulose content), as effective variable on quality of fibers was measured. Also for probing the chemical characteristic of fiber surface, FT-IR test was utilized. In addition, the wettability of fibers also was determined by measuring the contact angels between fibers surface and water drop. The results showed that the chemical composition of fibers is changed within recycling process. Most changes were occurred in hemicellulose and extractives content. The results of FT-IR test revealed the existence of more carbonyl groups and furfural and lower amount of hydroxyl groups in recycled fibers compared to original fibers which caused by esterification process. The wettability of fibers was decreased after recycling process especially in hydrothermal method.
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.
Mohammad Alishahi; Omid Ramezani; Hossein Kermanian; Mehdi Rahmani nia; Seid Atefeh Nasiri; Sahar Jalalvand
Abstract
In this research, the influence of paper drying condition, as one of the most important variable in paper recycling, on the characteristics of fibers was studied. In this respect, bagasse soda pulp was collected from Pars Paper mill in Khozestan province and handsheets were made. The control hand sheet ...
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In this research, the influence of paper drying condition, as one of the most important variable in paper recycling, on the characteristics of fibers was studied. In this respect, bagasse soda pulp was collected from Pars Paper mill in Khozestan province and handsheets were made. The control hand sheet samples were dried at room temperature and the rest of the handsheets were dried using drum dryer set at 60° C for 3 hours, 100° C for 50 minutes and 120° C for 25 minutes to reach the same moisture content as the sheets dried at room temperature. Then, these handsheets were slushed in water and the pulp properties were determined. The results showed that with increasing the drying temperature, cellulose content did not change while hemicelluloses were reduced. Although the assessment of changing the lignin content with micro kappa method showed an increasing trend, but based on previous literature, it was concluded that the result are not justified. Also, the results indicated that changing the degree of polymerization and crystallinity did not show a consistent trend, showing initial reduction following by increased values. These results were attributed to interaction effect of drying temperature and time.
