Document Type : Research Paper
Authors
1 Department of Wood and Paper Science and Technology, Karaj Branch, Islamic Azad University, Karaj
2 Associated Professor of Wood and Paper Science and Technology, Karaj Branch, Islamic Azad University, Karaj
3 Prof., Payame Noor University, Tehran, I.R. Iran.
4 Assistant Professor, Wood and Paper Science and Technology, Karaj Branch, Islamic Azad University, Karaj, Iran.
Abstract
Soda - oxygen pulping of old corrugated container to produce totally chlorine free bleached pulp was investigated. In order to reach the optimum delignification condition; four levels of sodium hydroxide (9, 11, 13, and 15 %), three cooking times (90, 120, and 150 minutes) and two cooking temperatures (120, and 150 ºC) at 6 bar oxygen pressure were studied. Yield and kappa number of pulps were measured. Results showed that the pulp obtained applying 9% sodium hydroxide, 150 minute delignification time and 150 ºC delignification temperature which produced the pulp with the yield and kappa number of 72.44% and 24.72 respectively was suitable for further bleaching. Strength of selected pulp including burst strength, tensile strength, and tear strength indices were measured as 2.27 kPa.m2/g, 29.19 Nm/g and 10.24 mN.m2/g respectively. The pulp was bleached applying 3% H2O2 and 2% NaOH to reach the final brightness of 57.97% ISO.
Keywords
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