Filler Quantification
Mineral analysis involves identifying and measuring the amount of hydrated aluminium silicate used as a filler or coating pigment in paper. Kaolin clay determination allows manufacturers to assess how this material affects the brightness and opacity of the board. This process often combines ash testing with advanced techniques like x-ray diffraction to distinguish clay from other minerals.
Print Performance
The presence of clay in the surface layer improves the ink holdout and reduces the amount of ink required for high quality graphics. During kaolin clay determination, the particle size distribution is also considered, as finer clays provide better gloss while coarser ones improve the smoothness. If the clay content is too high, the surface may become brittle and prone to cracking at the folds.
The chemical compatibility between the clay and the binders is necessary for a stable coating.
Economic Impact
Using minerals as a substitute for wood fibres can lower the overall cost of the material. Reliable kaolin clay determination ensures that the substitution does not exceed the point where the strength of the board is compromised. It also helps in managing the wear on the paper machine, as clay is less abrasive than some other fillers.
Monitoring the retention of these particles in the wet end is a part of maintaining an efficient production process.
