Barrel Maintenance

Proper maintenance of the twin screw extruder barrel is critical for performance and safety. The barrel should be kept clean and free of material buildup through regular cleaning procedures.It's essential to conduct regular inspections and assessments of the screw and barrel, considering both visual inspections and performance monitoring. A proactive approach to maintenance can help avoid unexpected failures and optimize the efficiency and longevity of the extrusion equipment.With proper care, twin screw extruder barrels can last years before needing replacement.

Cleaning Procedures

• After each job, thoroughly clean the barrel using purge compounds designed to remove residues. Polypropylene and high melt index polyethylene work well as mechanical cleaning agents. Chemical or abrasive cleaners may also be needed for more stubborn buildup. Always follow recommended safety procedures when cleaning.

• Completely disassemble the barrel at scheduled intervals for deep cleaning. Inspect all parts and surfaces. Replace any worn or damaged components.

• For optimal performance, use a barrel scraper or wire brush specially designed for cleaning extruder barrels. Manual cleaning can be tedious and risky. Automatedscrapers provide more thorough cleaning with less labor.

  
  

Inspections and Monitoring

• Visually inspect the barrel before each use for obvious damage or issues. Look for corroded, eroded, cracked, warped or worn surfaces. Confirm temperatures zones are operating properly.

• Periodically perform detailed inspections of the entire barrel assembly. Check dimensional clearances and alignments. Inspect surfaces under bright light for microscopic wear and erosion.

• Monitor operating conditions like temperature, pressure, torque, and power consumption. Significant changes can indicate developing issues like worn screws/barrel, sticking valves, or clogged screens.

  
  

Lubrication Needs

• Many twin screw extruders require barrel lubrication to prevent excessive wear, torque, and heat generation. Always use lubricants rated for high temperatures.

• Oil or grease injection ports allow lubrication of the screw elements and barrel without disassembly. The lubrication rate should be adjusted based on operating conditions.

• Graphite powder can help lubricate and protect metal barrel surfaces. For non-abrasive fillers, consider a graphite spray coating applied during maintenance cleanings.

Proper barrel care is essential for efficiency, output quality, and safety. Following scheduled cleaning, inspection, and lubrication procedures will maximize barrel life. Alert maintenance teams to any signs of wear or damage observed during operation.

Troubleshooting

When it comes to troubleshooting issues with twin screw extruder barrels, there are a few common problems that can arise. Being able to properly diagnose and address these problems is key to keeping your extrusion process running smoothly.

Common Barrel Issues

Some of the most common barrel issues include:

• Wear and abrasion: This can occur over time, especially in high temperature and high shear zones near the feed section. It leads to dimensional changes in the barrel that negatively impact performance.

• Corrosion/chemical attack: Certain materials being processed can corrode or degrade the barrel lining over time. This causes surface roughness and can lead to issues like pinholing.

• Cracks/mechanical damage: Cracks or deep gouges in the barrel surface provide spaces for material to collect. This disrupts flow and can cause issues like burning.

• Build-up/accumulation: Some materials are prone to sticking to the barrel surface, causing build-up over time. This can restrict flow channels and alter pressures.

  
  

Diagnosing Problems

Picking up on issues early allows for preventative maintenance. Signs of potential barrel problems include:

• Variations in product quality

• Excessive motor load

• Increased vibration/noise

• Leaking/weepage

When issues are suspected, thorough inspection both visually and with equipment like borescopes is recommended. The location and type of damage provide clues as to the root cause.

Repair and Replacement

Replacing a worn barrel before failure avoids unplanned downtime and maintains product quality.Deciding when to replace worn parts of the screw and barrel in an extruder involves assessing various factors related to their condition and impact on performance. Here are some considerations:

• Extent of Wear:

  If the wear on the screw and barrel is extensive and beyond the acceptable tolerance limits, replacement may be necessary. Excessive wear can compromise the extrusion process and product quality.

• Performance Degradation:

  Monitor the extruder's performance over time. If you observe a significant decline in output, increased energy consumption, or inconsistent product quality that cannot be corrected by adjustments, it may indicate the need for replacement.

• Material Compatibility:

  Changes in the processed materials, especially if they are more abrasive or corrosive, can accelerate wear. If the screw and barrel are not designed to handle the specific materials being processed, replacement may be required.

• Frequency of Repairs:

  If the screw and barrel require frequent repairs, it might be more cost-effective in the long run to invest in replacements. Persistent issues may indicate that the components have reached the end of their service life.

• Technological Advances:

  If there have been advancements in screw and barrel technology or if newer materials can provide improved wear resistance, it might be beneficial to consider replacement for better performance and efficiency.

  Work should only be done by qualified technicians to avoid operational safety risks. Following recommended preventative maintenance schedules can help minimize major repair costs over time.Nanjing jieya provides twin screw extruder spare parts service ,including repairing and in-situ replacement of the worn screw barrels and elements.Feel free to contact jieya@njjieya.com, if anything we could support!