Improvement of printing and writing paper properties using PCC Filler Modified by cationic starch modified precipitated calcium carbonate filler

Aim of this study is precipitated calcium carbonate cationic modification and comparison of impact of using its with conventional filler (unmodified) on strength properties of paper. One of the defects of adding fillers to paper is decreasing of mechanical strength of paper because of reduction in bonding area between fibers. In this study whit purpose of maintaining the strength of paper، and change the surface charge of precipitated calcium carbonate and replace it with conventional fillers are used. in this research with aim of precipitated calcium carbonate and replacing it with conventional filler was used. Condition of cationic precipitated calcium carbonate preparation was 90 ċ temperature، 3 hours time and 55% water content of cooking process. loading amount of starch was 9، 12 and 15 percent based on precipitated calcium carbonate weight. Papers made at three level: 10، 16، 30 percent of filler in paper sheets contain conventional fillers were compared. Results indicated that papers containing modified-filler have more values of retention rather than those with unmodified filler، both in 20% and 30% filler dosages. papers contained cationic filler have more mechanical strength index in respect of papers contained conventional fillers.