The quality control of masterbatch is the core link to ensure the color consistency, performance stability and production efficiency of plastic products, involving the entire chain of raw material selection, process control, testing standards and supply chain management. The following are the key points of systematic quality control and industry best practices:
I. Raw material quality control (source control)**
1. **Pigment/filler screening**
- **Purity requirements**: titanium dioxide (rutile type) TiO₂ content ≥94%, heavy metals (Pb/Cd/As) <10ppm (FDA/ROHS compliant).
- **Particle size control**: Inorganic pigment D50 ≤1μm (such as carbon black), organic pigments require surface treatment to prevent migration.
2. **Carrier resin matching**
- **Melt index (MI)**: The difference with the substrate resin is ≤20% (such as PP substrate uses a carrier with MI 10–25g/10min).
- **Compatibility test**: No precipitation after mixing at 180℃ for 5min (microscope observation).
II. Key Controls in the Production Process
III. Core performance testing system
