Document Type : Research Paper
Authors
1 Assistant Professor, Department of Bio-refinery Engineering, Faculty of New Technologies Engineering, Shahid Beheshti University, Zirab , Mazandaran, Iran
2 Graduated Student, Department of Bio-refinery Engineering, Faculty of New Technologies Engineering, Shahid Beheshti University, Zirab , Mazandaran, Iran
3 Assistant Professor, Department of Bio-refinery Engineering, Faculty of New Technologies Engineering, Shahid Beheshti University, Zirab , Mazandaran, Iran.
Abstract
Background and purpose: Paying attention to the resistance properties of paper during its production and consumption has always been particularly fashionable for paper makers. In the case of NSSC pulp, it is very important to maintain its resistance and continuous production for the production of floating papers or the combination in the production of various types of liner paper. The use of recycled papers in pure form or in combination with virgin papers has shown that the resistance properties of the resulting papers are reduced. Therefore, in order to use recycled paper, either pure or combined with virgin pulp, it is necessary to take measures to improve the quality of the final paper.
Materials and methods: This research was conducted to investigate the effects of using oxidation methods with hydrogen peroxide and hypochlorite to monitor the characteristics of congress corrugated pulp by combining NSSC and OCC pulps. In this research, firstly, the desired pulps were oxidized using hydrogen peroxide and sodium hypochlorite in different proportions, and then according to the TAPPI standard, handmade papers of 127 g/cm2 were made from them. Finally, the mentioned papers in terms of physical characteristics such as Cobb-60 and Air resistance; And the mechanical strength were evaluated
Results: The control treatments have more water absorption resistance and its amount decreases with the oxidation treatment of the pulps. Papers obtained from pulps oxidized with hypochlorite have more resistance to air passage than with peroxide. In this sense, the paper obtained from pure OCC treatment has the lowest air resistance. Papers obtained from pulps oxidized with peroxide have more tear index. Therefore, it seems that peroxide is preferred in terms of tearing properties compared to hypochlorite. In most cases, papers obtained from hypochlorite treatment have more tensile index. The use of oxidation with hypochlorite increases the forld resistance. In terms of CMT, RCT and CCT resistances, combined oxidation processes have been more effective, especially in treatments containing long fibers. The effect of oxidation with peroxide and hypochlorite on the resistance of the paper surface in NSSC and OCC papers are completely different and act in the opposite direction. But in combined treatments, more CMT is obtained. The effect of both oxidants on the characteristics of resistance to ring crushing (RCT) in NSSC and OCC papers in pure treatments has an upward trend, and in the combined state, it causes a decrease in RCT in the papers. The effect of oxidation with hypochlorite on the paper edge cramp resistance (CCT) has been higher compared to peroxide
Conclusion: The use of oxidation treatment with peroxide for all pulps makes the resulting papers have a higher tearing index. However, in the use of hypochlorite, the resistance characteristics affected by the bond between fibers, such as tensile strength and folding resistance, have been improved. In terms of resistance characteristics such as CMT, RCT and CCT resistance, the combination of peroxide and hypochlorite treatments along with long fibers have been more effective, therefore, considering the importance of these characteristics in the production of congress paper, it is suggested that these treatments should be prioritized.
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