The Effect of Cationic Polyacrylamide as Retention Aid for Alkaline Papermaking

Abstract

Alkaline paper has advantages in their high shelf life (permanence) compared to paper made in acidic conditions. The conversion from acidic papermaking process to alkaline process is a major change experienced by the paper industry. In alkaline papermaking, one of the internal sizing agent used is Alkylketene Dimer (AKD). This additive is used to improve the resistance of paper to liquid penetration. Changes to the use of sizing agents are also followed by other changes; one of them is the change in the retention aids used. The use of Cationic Polyacrylamide (C-PAM) as retention aid on alkaline papermaking which is sized by AKD has been investigated. In this study, 100% Leaf Bleached Kraft Pulp (LBKP) as a fiber source was refined in a laboratory beater up to 400 mLCSF of freeness and then mixed with paper additives i.e. 0.1% AKD as sizing agent, 15% calcium carbonate as filler and 1% cationic starch as dry strength agent. The addition of C-PAM was varied in the range of 0% - 0.4% based on dry weight of fiber. After being mixed thoroughly, the handsheets of 60 g/m2 grammage were made and then tested for tensile strength and water absorption (Cobb-60). The addition of 0.1% C-PAM resulted paper with good tensile strength and improved the resistance to liquid penetration. Keywords: Alkaline paper, AKD sizing, C-PAM, tensile strength, water absorption (Cobb-60) DOI: 10.7176/CMR/12-6-04 Publication date: July 31 st 2020