Paint and coatings are typically screened at 40 to 325 mesh (400 to 45 microns) depending on the application. Powder coatings use 60 to 200 mesh for particle size classification, liquid paints use 60 to 325 mesh for straining, and raw pigments and fillers use 100 to 400 mesh for de-agglomeration before dispersion.
Screening is critical in paint and coatings manufacturing because a single oversize particle or agglomerate can cause visible defects in the finished surface. In powder coating, oversized particles cause orange peel, spitting, and uneven coverage. In liquid paint, gels and agglomerates create fisheyes, craters, and visible bumps. ScreenerKing supplies stainless steel screens for both dry powder coating and liquid paint straining applications.
Recommended Mesh Sizes by Application
| Material / Application | Mesh Size | Micron Size | Purpose |
|---|---|---|---|
| Powder coating — production grade | 100–140 mesh | 150–106 µm | Remove oversize for smooth application |
| Powder coating — reclaimed overspray | 80–100 mesh | 180–150 µm | Re-screen reclaimed powder before reuse |
| Powder coating raw resin | 60–100 mesh | 250–150 µm | Safety screening of incoming resin powder |
| Liquid latex paint — straining | 60–100 mesh | 250–150 µm | Remove skins, gels, and agglomerates |
| Liquid automotive paint | 150–325 mesh | 106–45 µm | Ultra-fine straining for defect-free finish |
| Industrial epoxy / polyurethane | 80–200 mesh | 180–75 µm | Remove gels and contaminants before application |
| Printing ink | 200–325 mesh | 75–45 µm | Fine straining for smooth print quality |
| Pigment dispersion (TiO2, iron oxide) | 100–400 mesh | 150–37 µm | De-agglomerate pigment for color uniformity |
| Filler materials (calcium carbonate, talc) | 80–200 mesh | 180–75 µm | Classification for paint filler applications |
Factors That Affect Mesh Selection for Paint and Coatings
- Application method: Spray applications require finer particle sizes than roller or brush applications. Electrostatic powder coating guns work best with 25 to 90 micron particles. Automotive spray paints require the finest straining at 200+ mesh.
- Finish quality: Higher gloss and smoother finishes demand finer screening. Matte and textured finishes tolerate larger particles. Match screening to the final surface quality specification.
- Wet vs. dry: Liquid paint straining and dry powder classification require different screener configurations. Liquid screening needs proper gaskets, drainage, and solvent-compatible seals.
- Solvent compatibility: Ensure screen material and gaskets are compatible with the solvents in your formulation. Many paint solvents attack rubber gaskets and some non-metallic screen materials.
- Viscosity: High-viscosity coatings screen slowly. Higher viscosity requires either coarser mesh, larger screen area, or thinner product to maintain throughput. Some operations heat paint slightly to reduce viscosity for screening.
Screen Material Recommendations
316 stainless steel is recommended for most paint and coatings screening. 316 SS resists corrosion from solvents, acids, and chemical additives in paint formulations. It is the standard for solvent-based and industrial coating applications.
304 stainless steel is acceptable for water-based latex paints, powder coatings, and dry pigment screening where solvent resistance is not a concern.
T-430 stainless steel is less common in paint applications but can be used where magnetic contamination detection is part of the quality program.
Equipment Recommendations
- Small coating shops and lab (under 500 lb/hr): ScreenerKing SiftPro 18" or 24" — ideal for small-batch powder coating and paint straining.
- Mid-volume coating production (500–3,000 lb/hr): ScreenerKing SiftPro 30" — handles production powder coating screening and liquid paint straining.
- Large paint manufacturers (3,000–10,000 lb/hr): ScreenerKing SiftPro 48 (48") — industrial-capacity screening for paint and coatings plants.
- Bulk pigment and filler suppliers (10,000+ lb/hr): ScreenerKing SiftPro 60 — maximum throughput for raw material processing.
Frequently Asked Questions
What mesh size is used for powder coating?
Powder coatings are screened at 60 to 200 mesh (250 to 75 microns). Production screening typically uses 100 to 140 mesh to remove oversize that causes surface defects. Reclaimed overspray is re-screened at 80 to 100 mesh before reuse.
Can I screen liquid paint with a vibratory screener?
Yes. Vibratory screeners strain liquid paint at 60 to 325 mesh to remove gels, skins, and agglomerates. Configure the screener with proper gaskets, drainage, and solvent-compatible seals. ScreenerKing screeners can be set up for liquid screening.
What screen material is compatible with paint solvents?
316 stainless steel resists corrosion from most paint solvents, acids, and additives. 304 SS is acceptable for water-based paints and dry powder coatings. Always verify compatibility with your specific solvents.