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
Moghadaseh Akbari; Nadia Kabodi torabi; Hossein Rrsalati; Gasem Asadpour atoei; Mohammad reza Dehghani firozabadi
Abstract
Aim of this study is precipitated calcium carbonate cationic modification and comparison of impact of using its with conventional filler (unmodified) on strength properties of paper. One of the defects of adding fillers to paper is decreasing of mechanical strength of paper because of reduction in bonding ...
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Aim of this study is precipitated calcium carbonate cationic modification and comparison of impact of using its with conventional filler (unmodified) on strength properties of paper. One of the defects of adding fillers to paper is decreasing of mechanical strength of paper because of reduction in bonding area between fibers. In this study whit purpose of maintaining the strength of paper, and change the surface charge of precipitated calcium carbonate and replace it with conventional fillers are used.in this research with aim of precipitated calcium carbonate and replacing it with conventional filler was used. Condition of cationic precipitated calcium carbonate preparation was 90 ċ temperature, 3 hours time and 55% water content of cooking process. loading amount of starch was 9, 12 and 15 percent based on precipitated calcium carbonate weight.Papers made at three level: 10, 16, 30 percent of filler in paper sheets contain conventional fillers were compared. Results indicated that papers containing modified-filler have more values of retention rather than those with unmodified filler, both in 20% and 30% filler dosages.papers contained cationic filler have more mechanical strength index in respect of papers contained conventional fillers.
