Revamping of Paper Properties with Combination of Cationic Starch and Guar Gum in Modern Paper Making

Abstract

Bursting strength, opacity, sizing, weight and ash of the paper are among the most extensively studied paper properties that are of prime importance from printing and writing point of view. Several additives and operational strategies are currently in use to make the paper making process more economical and cleaner however, the stable wet-end chemistry plays a vital role in paper production cost and enhances machine efficiency and decreases the downtime. This study is aimed to explore the benefits of adding combination of cationic starch and guar gum on wet-end process to achieve refinement in paper properties. Also, the goal was to reduce the dosage of costly cationic starch while keeping paper characteristics to acceptable limits. This paper provides a guideline for reducing the cost of paper making by using replacing a portion of starch with guar gum for achieving multiple outcomes such as the process efficiency and quality control. Cooked starch and guar gum blend (50:50) ratio was added in thick stock with varying doses 0.4%, 0.6%, 0.5% and 1% of paper making furnish. The combination gives a better first-pass retention (FPR), strength and opacity in comparison to cationic starch only. Application of cationic starch and guar gum combination in thick stock of paper making furnish enhanced the bursting index of paper from 1.5 to 2.5 gf/cm², ash of paper 1.5 to 3% and 2 to 3% raise in opacity of paper owing to superior filler retention level in paper. Wet end chemistry impacts run-ability, final quality of the paper, and overall machine efficiency remains stable with these additives in furnish.