Pulp and paper
omid yazdani aghmashhadi; Ghasem Asadpoor; Esmaeil Rasoli garmarodi; Reza Imani
Abstract
Bank-note during in its lifetime exposed to different environments and various applicationns with high frequency. As it is confirmed in scientific studies, bank-note can be one of the most important and perhaps rarest of disease and parasites carriers in society. The goal of this study is evaluation ...
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Bank-note during in its lifetime exposed to different environments and various applicationns with high frequency. As it is confirmed in scientific studies, bank-note can be one of the most important and perhaps rarest of disease and parasites carriers in society. The goal of this study is evaluation of the appropriate solution for antibacterial banknote paper production using silver nanoparticles as an antibacterial agent and a cationic polyacrylamide as retention aid. Laboratory pulp of cotton fibers bleached with hydrogen peroxide with freeness of 34 °SR, consistency of 3.1% and neutral pH were prepared and then above additives were added with specified conditions (nano silver with 25, 50, 75 and 100 ppm with 0.3% percent cationic polyacrylamide) and finally 90 g/m2 standard handsheets made from above mentioned pulp. To verify the presence of silver particles in paper structure, the hand sheet papers were characterized by SEM. UV-vis spectrophotometric method was used to evaluate of antibacterial properties of paper. Also, papers were analyzed in strength and optical properties. The results showed that with increasing the silver nanoparticles consumption, paper strength properties and brightness were decreased, and opacity increased. The biological test results showed that the antibacterial properties of paper were improved with silver nanoparticles consumption. Based on the results of strength, optical and biological tests and also economic and environmental overviews, 25ppm consumption of nano-silver was determined as optimized treatment.
Pulp and paper
mojtaba goli; Ghasem Asadpur; Saeed Mahdavi; Abdollah Barimani
Abstract
Importing of wood is a solution to supplying raw material in the Iranian paper industry because of wood shortage. Therefore, the effect of mixing the imported aspen roundwood with the two hardwood native forest species including hornbeam and beech were perused on the optical and mechanical properties ...
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Importing of wood is a solution to supplying raw material in the Iranian paper industry because of wood shortage. Therefore, the effect of mixing the imported aspen roundwood with the two hardwood native forest species including hornbeam and beech were perused on the optical and mechanical properties of CMP pulp. Cooking constant conditions consist of maximum temperature were 170 °C with a liquor-to-wood ratio (L/W) of 7, and chemical content of 20% based on the oven-dry weight of the wood chips. CMP pulps were prepared at different cooking times of 30 to 120 minutes using 20, 30, 40, 60, and 100% aspen wood in combination with the two species to achieve the yield of nearly 85%. Standard laboratory handsheets were made after pulp refining by 300 ml CSF, and then the strengths and optical properties were measured. Statistical analysis of result showed that there were significant differences among of the properties of CMP pulps by increasing the aspen wood ratio. All the properties have been improved except opacity paper. The required strength of newsprint and printing/writing paper made in Mazandaran wood and paper industries (MWPI) could be achieved by mixing of 20 and 30% imported aspen wood to the native species used in currently, respectively.