Application of polysaccharide based modified ground calcium carbonate in wet‐end of papermaking

Abstract

To enhance the ash in paper without reducing its strength property, ground calcium carbonate (GCC) filler was modified using polysaccharide prior to its addition at wet‐end of papermaking. Till now, modification of GCC filler using chitosan acetate (CH.A) is not explored. The novelty lies in showing the effect of CH.A as GCC filler modifier and its application in papermaking. The results showed that ash of paper get increased by around 18%, 53% and 63% after adding GCC modified using cationic starch (C.S) @ 20 kg/t of GCC, CH.A @ 5 kg/t of GCC and CH.A @ 10 kg/t of GCC respectively, in comparison to that attained by paper using unmodified GCC at the same dose at wet‐end of papermaking. The breaking length, burst factor and tear factor of paper having 11% ash (made using unmodified GCC) was found to be 2485 m, 21.73 and 47.63, respectively. The paper having 18% ash (made using GCC modified by CH.A 10 kg/t of GCC) showed breaking length, burst factor and tear factor as 2364 m, 22.24 and 46.72, respectively. This approach of using CH.A in papermaking will help the papermaker to improve profit and quality of paper.