How to produce transparent blue tone White pigment paste with Kmeris micro titanium Dioxide?

After preparing the raw material and equipment, next is the Preparation Procedure.

Step 1: Pre-Mixing

1. Weigh all formulation components according to the percentages listed above.

2. Charge the solvent (butyl acetate) into a clean mixing vessel.

3. Add the dispersant (KBS-F500/50 or BYK-180) and acrylic resin to the solvent, and mix thoroughly until homogeneous.

4. Gradually add the Kmeris nano-titanium dioxide powder to the liquid mixture while stirring continuously.

5. Continue stirring at moderate speed until all pigment particles are wetted and a uniform paste is formed.

6. If available, use a high-speed disperser at 1,500–2,500 rpm for 10–15 minutes to achieve initial dispersion and break down large agglomerates.

Step 2: Bead Milling (Grinding)

1. Transfer the pre-mixed paste into the sand mill hopper or feed tank.

2. Ensure the mill chamber is filled with zirconia beads (1.0–1.5 mm diameter) at a 70%–80% filling ratio.

3. Start the mill and circulate the paste through the grinding chamber.

4. Operate the mill in recirculation mode — continuously circulating the paste until the required fineness is achieved.

Step 3: Fineness Inspection

• Periodically take samples from the circulating paste.

• Measure the particle fineness using a Heitman gauge / grindometer (fineness of grind gauge).

• Continue milling until the desired fineness specification is reached (typically ≤ 5–10 μm for nano-TiO₂ pigment pastes, or as per the specific end-use requirement).

Step 4: Discharge and Filtration

1. Once the target fineness is achieved, discharge the finished pigment paste from the mill.

2. If necessary, filter the paste through a screen or filter bag to remove any oversize particles or worn beads.

Process Parameters Summary

Quality Control Checks

After preparation, the following quality parameters should be verified:

Notes and Recommendations

1. Wetting is critical: Nano-titanium dioxide has a high surface area and strong tendency to agglomerate. Ensure the dispersant is fully dissolved in the solvent system before adding the pigment.

2. Temperature control: During milling, friction may cause temperature rise. Excessive heat can degrade the resin or alter the dispersion quality. Use a cooling water jacket if available and keep the mill temperature below 45–50°C.

3. Bead filling ratio: Maintaining 70%–80% bead fill is essential for efficient grinding. Lower fill ratios reduce grinding efficiency, while higher ratios may cause excessive heat generation or mill blockage.

4. Dispersant adjustment: When using BYK-180 as a replacement for KBS-F500/50, the optimal dosage may vary. It is recommended to conduct a small-scale trial to determine the optimum dispersant level before full-scale production.

5. Solvent adjustment: Any change in dispersant type or dosage should be compensated by adjusting the solvent content to maintain the total formulation at 100%.

6. Storage: Store the finished pigment paste in sealed containers, away from direct sunlight and heat sources, to prevent solvent evaporation and skin formation.