In the world of injection molding, the screw and barrel are at the heart of the plasticizing process. However, constant exposure to heat, pressure, and abrasive materials inevitably leads to wear. Understanding injection molding screw and barrel wear is essential for reducing downtime, improving part quality, and extending equipment life.
What Is Screw and Barrel Wear?
Wear refers to the gradual material loss or surface damage of the screw flights and barrel inner wall due to friction, corrosion, and abrasion. It can happen at different zones: feed, compression, and metering. The result? Inconsistent melt, reduced shot size, black specs in molded parts, and ultimately production delays.
📊 According to Plastics Technology Magazine (source), screw-to-barrel clearance exceeding 0.2 mm typically signals excessive wear and decreased efficiency.
Common Causes of Wear
- Abrasive Fillers
Materials like glass fiber, calcium carbonate, and talc increase abrasion.
TIP: Use bimetallic barrels and hard-faced screws to handle these materials. - Corrosive Resins
Resins like PVC, POM, and flame-retardant compounds can corrode unprotected metals.
TIP: Opt for screws coated with Colmonoy or tungsten carbide. - High Processing Temperatures
Prolonged exposure to 300°C+ can cause material softening and accelerated wear. - Poor Maintenance
Rarely cleaning the screw or ignoring material contamination can cause localized wear and surface damage.
How Fast Does Wear Happen?
The rate of wear depends on:
- Raw material type
- Processing temperature
- Additive content
- Machine design
📌 SPI (The Plastics Industry Association) reports that unprotected screws processing glass-filled resins may need repair or replacement within 6–12 months, while bimetallic versions can last 3–5 years with proper maintenance (source).
Wear-Resistant Solutions
✅ Bimetallic Barrels – Made of wear-resistant alloys (like nickel-based 101 or 301), ideal for tough materials.
✅ Colmonoy-Coated Screws – PTA-welded alloy for high abrasion and corrosion resistance.
✅ Nitrided Steel Screws – For standard resins with moderate wear potential.
Top Injection Molding Brands & Their Screw Barrel Recommendations
- ENGEL Austria: Recommends regular screw inspection and offers high-hardness options for specialty polymers
- ARBURG: Uses advanced metallurgy for long screw-barrel lifespan in technical molding
- HAITIAN: Supports bimetallic options through OEM and aftermarket supply chains
- JSW (Japan Steel Works): Known for screw designs optimized for reduced wear in high-speed molding
These brands emphasize screw and barrel maintenance as a key part of maximizing machine performance.
How to Check for Wear
- Measure the screw outer diameter and barrel inner diameter
- Compare with original specifications
- If clearance > 0.2 mm, performance likely suffers
- Look for melt inconsistency, pressure drops, or black specks in molded parts
🔧 When to act? If wear exceeds tolerance limits, consider repair (hardfacing, relining) or replacement.
Need Replacement or Repair?
At Zhoushan Juyuan Machinery Co., Ltd., we specialize in manufacturing and repairing injection molding screws and barrels for all major brands and materials.
Why Choose Us:
- 20+ years of experience
- Colmonoy hardfacing, bimetallic barrel options
- OEM design support and fast global delivery
- Custom solutions for ENGEL, ARBURG, HAITIAN, JSW, and more
🔗 Check our Injection Molding Screw Barrel Products
🔗 Explore our Bimetallic Barrel Options
Final Tips to Reduce Wear
- Match screw design to your material
- Regularly clean and inspect components
- Avoid overheating or extended idling
- Use correct start-up and shut-down procedures
Contact Us Today
📧 Email: cxj.job@gmail.com
📱 WhatsApp: +86 13905808474
🌍 Website: https://juyuan-machinery.com
Let us help you extend the life of your injection molding machine — with expert screw and barrel solutions.