Maximum colour strength in paint and lacquer: prevent both air entrainment and poor wetting
Every producer of paint and lacquer knows the importance of high colour strength. Yet in practice, it proves difficult to disperse pigments properly. Air entrainment is often identified as the cause, but the real problem lies deeper. Air is not the only factor that hinders the process; insufficient wetting of pigment particles also leads to colour loss.
Two causes, one solution
During dispersing, pigment particles must dissolve completely in the liquid. If air gets between them, bubbles and foam form. This impedes the shear forces in the dispersing zone, which means that not all the pigment is processed to the maximum extent. At the same time, many pigments are difficult to wet. As long as the pores still contain air, the liquid cannot penetrate properly. The particles then remain on the surface or in agglomerates.
Dispersing under vacuum: maximum pigment uptake
The Rmixx RMC powder-dissolving and dispersing machines address both problems simultaneously. Powder is drawn in under vacuum, with the air being extracted from the pigment particles before wetting takes place. As a result, even pigments that are difficult to wet are incorporated directly into the liquid. This produces a powerful, air-free dispersion in a short time.
The benefits
- High colour strength: all the pigment is utilised
- Efficient process: less time lost, no foam formation
- Stable batches: fewer manual corrections required
Tips for good pigment dispersion
- Use a machine that operates with a vacuum in the dispersing zone (example of a vacuum inline dispersing machine)
- Only add powder in a dispersing zone under vacuum
- Avoid open systems in which air is quickly drawn in
- Read more in our article about the difference between inline and batch dispersing
- Also view the meaning of dispersing in our knowledge base
Would you like to know more or get started straight away?
Contact RS Contracting on +31 524 522 722 or email [email protected] for personal advice. You can also view the applications of inline dispersing machines on our website.
