Surface-Treated Series
Stearic-acid surface treatment transforms a mineral filler into a polymer-ready ingredient — hydrophobic, easy to disperse and measured, not assumed: every grade's coating level is verified by thermal analysis.
The Coating Science
Stearic acid is applied as a surface treatment to improve the hydrophobicity and dispersion of calcium carbonate in polymer systems. The treated particle wets into PE, PP, PVC and rubber matrices instead of agglomerating — improving processing behavior and surface finish.
We verify the coating on every grade using a thermal mass-loss method: samples are dried at 105 °C, then treated at 350 °C in a muffle furnace, and the measured mass difference gives the exact stearic acid percentage.
| Grade | Stearic acid (measured) |
|---|---|
| 5 µm | 1.47% |
| 8 µm | 1.36% |
| 10 µm | 1.14% |
| 12 µm | 1.06% |
| 15 µm | 0.88% |
| 20 µm | 0.75% |
Finer grades carry proportionally more coating — more surface area demands more treatment. Values are measured coating levels by thermal analysis.
The Grades
Finest coated grade — 1.52 µm median, 4.10 µm top cut, 1.47% measured coating for maximum dispersion in demanding systems.
High-performance balance of fineness and throughput — 2.10 µm median, 8.05 µm top cut, 1.36% measured coating.
General-purpose coated grade — 2.56 µm median, 9.61 µm top cut, 1.14% measured coating for smooth extrusion and molding.
Engineered for high-loading extrusion — 2.78 µm median, 11.69 µm top cut, 1.06% measured coating.
Economical coated grade — 3.05 µm median, 13.94 µm top cut, 0.88% measured coating for cost-optimized compounds.
Coarsest coated grade — 3.38 µm median, 18.26 µm top cut, 0.75% measured coating. High loading where economics lead.
Raw Material Control
The stearic acid we apply is itself quality-controlled before it ever touches the mineral.
Acid value, mg KOH/g
Iodine value, g I/100 g
Moisture
Unsaponifiable matter
Send us your polymer system and loading target — we'll recommend the grade and coating level that fits.
