Advantages of Commercial Rutile Titanium Dioxide Slurry for Paper Applications

Abstract

Paper mills have used titanium dioxide to generate opacity in high quality paper and paperboard for many years. Dry anatase pigments were used at first since this was the only technology available. Invention of the chloride rutile process created opportunities for new levels of performance in the paper industry. Commercial rutile slurry was introduced over 25 years ago to the North American marketand has been continually improved. Over 95% of the titanium dioxide used in this market is commercial slurry. More recently the use of stable paper slurries has been growing in both Europe and Japan.
Commercial rutile slurry offers performance advantages over slurry produced by the paper mill. High shear dispersion equipment allows optimization of the particle size and increased light scattering. Opacity gains of 10-12% have been demonstrated in the lab. Mill trials have confirmed even higher performance gains.
Anatase pigments have a lower refractive index and generally larger particle size. Both attributes will contribute to lower scattering performance than a rutile pigment. Mill trials have demonstrated over 20% reduction in pigment use when switching from an anatase pigment to rutile.Handling and storage of slurry products is not difficult. Proper design of the equipment will insure trouble free operation and high product quality. Correct addition to the paper process will maintain the high performance of the pigment.