Most colour problems in plastics come down to a handful of causes. This checklist helps find them quickly.
| Symptom | Likely causes | What to check |
|---|---|---|
| Specks or dots | Poor dispersion, contamination, degraded material | Screen pack, cleanliness of hopper and dryer, residence time |
| Streaks | Carrier melting too late, low back pressure, poor mixing | Carrier match, screw design, back pressure, dosing position |
| Shade drift between batches | Dosing variation, regrind ratio, base resin colour | Dosing calibration, regrind control, resin lot |
| Weaker colour than expected | Under-dosing, thermal degradation of pigment | Actual dosing, melt temperature, residence time |
| Lacing or voids in film | Moisture | Masterbatch and filler moisture, drying |
| Warpage in mouldings | Nucleating effect of some pigments | Pigment choice, cooling and mould temperature |
If the problem persists, send us a sample of the part, the masterbatch lot number and your process settings.
