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Surface Blooming / Migration
Symptoms: A white, powdery residue or oily film appearing on the product surface over time.
Solutions:
- Optimize the TPE compounding system to improve compatibility.
- Reduce the concentration of low-molecular-weight additives.
- Ensure the processing temperature is within the recommended range.
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Poor Adhesion (Delamination)
Symptoms: The TPE layer peels off easily from the rigid substrate (ABS, PC, or PA) during overmolding.
Solutions:
- Increase injection temperature and speed to enhance molecular fusion.
- Ensure the substrate is free from grease, dust, or moisture.
- Pre-heat the rigid substrate before secondary injection.
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Sink Marks & Shrinkage
Symptoms: Depressions on the surface of thick-walled parts or dimensional inaccuracies.
Solutions:
- Increase holding pressure and duration.
- Enlarge gate and runner sizes to prevent premature freezing.
- Lower the mold temperature to stabilize cooling.
Standard Processing Parameters
| Material Type | Drying (°C/hr) | Melt Temp (°C) | Mold Temp (°C) |
|---|---|---|---|
| SEBS-based TPE | None / 60°C @ 2hr | 180 – 210 | 20 – 40 |
| TPU (Polyurethane) | 80 – 90°C @ 3hr | 190 – 220 | 10 – 50 |
| TPEE (Polyester) | 100 – 120°C @ 4hr | 220 – 250 | 40 – 70 |
Encountering a specific molding issue? Our lab is ready to assist.
