How particle size (2 to 6 µm) and particle shape (spherical vs flake) drive the choice between paints, electroplating, pharmaceutical chemistry and Geomet / Dacromet coatings.
Atso Tek supplies three grades of zinc dust, all tested per ISO 3549. The grades differ in two dimensions that matter for downstream performance: particle size and particle shape. Choosing the right one is the difference between a coating that holds for decades and a chemistry process that wastes raw material.
| Grade | Median size | Shape | Primary use |
|---|---|---|---|
| Superfine | 2 to 4 µm | Spherical | Industrial paints, anti-corrosion coatings, electroplating |
| Fine | 4 to 5 µm | Spherical | Catalysts, pharma chemistry, sensitive composites |
| Fine Flake | 4 to 6 µm | Flake | Zinc-rich paints, Geomet, Dacromet, plating |
Smaller particles mean more active surface area per kilogram. In a zinc-rich primer, that surface area is what couples the zinc galvanically to the steel below. The protective mechanism that gives the coating its corrosion resistance. Push the particle size up and the cathodic protection drops; push it too far down and you start to see flash corrosion of the dust itself before it ever reaches the steel.
Spherical particles flow well, pack densely and disperse cleanly in solvent-borne systems. Flake particles overlap like fish scales. And that overlap is the reason zinc-rich paints, Geomet and Dacromet coatings use Fine Flake instead of Superfine: the flakes physically barrier the surface against moisture and chloride ingress, while still providing galvanic protection at the metal interface.
If you are unsure which grade fits your formulation, send us your target binder system, dry-film thickness and corrosion class. We will recommend the grade and ship a sample with a full Certificate of Analysis for your QC team.
