The quality demands with respect to most types of paper are steadily rising. Higher brightness, higher opacity and better printability at constant or improved running properties with ever-faster paper coating machines are just a few of the criteria. These demands – combined with the trend towards increasing the amount of paper fillers – pose a great challenge to the manufacturers of pigments for paper.
Hosokawa supplies process solutions for the manufacture of different types of pigments for use in the production of paper.
We employ the vertical agitated ball mill ANR for the wet grinding of GCC.
PCC as an alternative to GCC
Precipitated calcium carbonate (PCC) is a synthetic product produced by means of a chemical precipitation process.
– High reliability
– Low energy consumption
– Steep particle size distribution
– Low rotor speed
– Long rotor life thanks to ceramic wear protection
– Contamination-free end-product
– Large cooling surface
– Low and high solids concentration possible
Kaolin and gypsum
Kaolin and gypsum are ground with the agitated ball mill AHM.
When grinding gypsum, additional know-how with respect to the additives used is necessary if the desired specifications are to be met. For coating operations, ground gypsum instead of kaolin can be used. Thanks to the low density, a thicker coating at constant weight (g/m2) is achieved with gypsum, or at the same layer thickness, the weight of the paper can be reduced and the gloss increased.
Drying calcium carbonate
Most of the cases of wet milled GCC and PCC after filtration, post drying is necessary. Hosokawa Drymeister (DMR-H) is the most recommended dryer for this application. Setting the high inlet air temperature, a very economical and effective drying condition is presented to calcium carbonate producers.
Drymeister provides three functions in one machine; grinding, drying and classifying. Thus, no further grinding is necessary.