1. Introduction

Waterborne colorant grinding process directly determines fineness, color strength and storage stability. This paper presents 5 key control points based on DENSON WT series production experience.

2. Technical Features

Wet grinding in horizontal sand mill uses zirconia beads to break pigment agglomerates under high shear. Temperature, bead size, flow rate and dispersant dosage are the main variables.

Fig.1 Horizontal sand mill for wet grinding

3. Case 1: Pigment Blue 15:3

For PB15:3, bead size 0.6-0.8 mm, line speed 10-12 m/s, temperature ≤40°C, D50≤0.2 μm (GB/T 19077).

4. Case 2: Carbon Black

Fig.2 Nanometer horizontal sand mill

Carbon black requires higher dispersant dosage (8-12% on pigment) and pH 8.5-9.5 to avoid flocculation.

5. Case 3: Titanium Dioxide

Fig.3 Sand mill rotor pin detail

TiO2 needs lower energy input; over-grinding causes viscosity rise and gloss loss.

6. Key Selection Parameters

More: DENSON waterborne colorant products.

7. Conclusion

Optimizing bead size, line speed, temperature and dispersant dosage is essential for stable waterborne colorant production.

8. FAQ

Q1: Why does temperature rise during grinding?
A: Shear and bead collision generate heat; cooling water must keep ≤40°C to avoid dispersant degradation.

Q2: How to judge grinding endpoint?
A: Use fineness gauge ≤15 μm (GB/T 1724) and D50 by laser diffraction (GB/T 19077).

Q3: Can I reuse zirconia beads?
A: Yes, but sieve out broken beads every 200 h and top up 10%.

Q4: What causes viscosity rise?
A: Over-grinding or insufficient dispersant; check pH and add dispersant.