The reason why the color paste produced by the sand mill cannot meet the requirements

Why do some factories use sand mills to produce color pastes that cannot meet the requirements? Some customers said that the fineness of the grinder they bought could not meet the requirements, which made them very confused. What are the common reasons why the grinding fineness does not meet the requirements? How to solve?
Reason 1: Pigment particles are difficult to disperse, such as carbon black, iron blue, etc.
Solution: In the production process, the following measures should be taken: first, rationally adjust the process, such as ball mill or three-roll mill grinding; second, the use of dispersants, carbon black and other solvents can also increase the dispersion power. The above method may affect the yield, so the pigment is mainly surface treated to strengthen the dispersion function of the abrasive.
Reason 2: The fineness of the paint paste itself cannot meet the requirements of the color paste.
Solution: The fineness of the paint paste should meet the specified fineness standard, otherwise the fineness of the color paste cannot be guaranteed. Therefore, paint slurry that meets the specified fineness should be used. In order to meet the requirements of the grinding paste, the user can find out the reason according to the actual situation, so that the fineness of the grinding paste can meet the requirements and improve the working power.
Reason 3: The content of pigment impurities is too high to be finely ground, such as mixed with paint, fiber, dust, fine sand and other impurities.
Solution: Rely on the paint supply department to strengthen management, prevent impurities from mixing, and ensure product quality; secondly, when matching color paste production workshops, paint filtration should be strengthened, and attention should be paid to identifiable impurities in the powder. When mixed impurities are dispersed, use full bucket, Residual hopper operation or single-roller grinding in series to filter residue.
Reason 4: The fineness of the pigment itself is greater than the fineness required by the color paste, so it cannot be polished. In many cases, this is because the primary particles of the pigment are larger than the fineness required for the color paste.
Solution: further process and destroy the pigment to make its particle size smaller than the required fineness of the color paste. Due to the dispersion process of the color paste grinding, the problem of further restoring the original particles cannot be solved.