Paper performance and the increased use of fillers and pigments

Paper mills are increasing the mineral content of paper by increasing the filler levels and applying more coating, via the size press. But there is a problem associated with these developments, i.e., the weakening of the final sheet. The author describes an anionic wet end starch which overcomes this problem. Up to 5% of this new starch can be absorbed compared to the conventional 1.5% retention level of cationic starch. With more retained starch, strength properties are increased. Studies show that the new system does not impair runnability. On the contrary, it may be positively influenced.