Barrier Screw vs Conventional Screw: Which Is Better for Blow Molding?
Introduction
Melt uniformity is critical in blow molding applications. Screw structure plays a decisive role in separating solid and molten phases during processing.
1. Conventional Screw Design
Traditional screws use a three-zone structure:
- Feed zone
- Compression zone
- Metering zone
While suitable for general applications, conventional screws may struggle with high-output requirements.
2. Barrier Screw Structure
Barrier screws introduce an additional flight to separate solid pellets from molten material.
This design:
- Improves melting consistency
- Reduces unmelted particles
- Enhances output stability
3. Performance Comparison
| Feature | Conventional Screw | Barrier Screw |
|---|---|---|
| Melt Uniformity | Moderate | High |
| Output Stability | Standard | Improved |
| Cost | Lower | Slightly Higher |
Conclusion
For high-output blow molding lines, barrier screw structures often provide better melt quality and long-term efficiency.