When it comes to coating additives, determining the exact particle size distribution is extremely important. The particle size has significant influence on the properties of the additive—the final appearance and feel (gloss, matting, softness), as well as the mechanical properties that all depend on the size and distribution of the particles.
Determining the particle size varies by additive. For example, micronized waxes are typically measured in dry medium, where it is sufficient to bring the particles into suspension by using air pressure to be able to measure them optimally.
For some micronized waxes, an optimal distribution must be created with the help of a solvent to determine the particle size. The same applies to emulsions and dispersions that can be optimally distributed in a solvent-containing medium to determine the particle size as accurately as possible.
At Lubrizol, we use a variety of equipment that is extensively tested when a new product or raw material is introduced so we can ensure we have developed the optimal testing method. To measure micronized waxes, our state-of-the art equipment enables this measurement to happen in a dry medium as well as in a wet medium. Doing so helps us to optimally measure the particles through compressed air or distribution in a liquid medium.
However, we also use long-established test methods, such as the Grindometer fineness, which is still a popular unit of measurement for printing inks.
In order to be able to perfectly exclude oversize grains, we use an application test in addition to the measuring equipment. During this test, the additives are incorporated into various coatings specially formulated for them and applied at different film thicknesses.
We can ensure that we are optimally determining the particle sizes of our products and that we always deliver consistent quality by using a wide variety of equipment and additional tests with the Grindometer and applications in paint.
Contact us to learn more about how we precisely determine and control particle size distribution.