Complete Maintenance Guide for Plastic Pelletizing Machines: Stop Breakdowns And Extend Machine Life

A plastic pelletizing machine is a core component of the plastics processing industry. Its long-term stability directly affects production efficiency, product quality, and overall operating cost. However, due to continuous high-load operation, material abrasion, and environmental factors, machine performance gradually declines.

In most cases, breakdowns are not sudden—they are the result of long-term neglect of proper maintenance.

This guide provides a full-cycle maintenance plan based on years of real production experience, covering daily checks, scheduled preventive maintenance, and emergency troubleshooting. Even beginners can follow it to extend machine lifespan and reduce repair costs.

1. Daily Maintenance (Simple but Critical)

Daily maintenance is the foundation of stable production, yet it’s often overlooked.

Spend 3–5 minutes before, during, and after each shift to build a reliable routine.

✔ Check the lubrication system

• Refill lubricant as needed.

• Oil should remain clear—if it turns dark or contains impurities, replace it immediately.

• Start the lubrication pump and listen for abnormal noise.

  Ensure smooth oil flow, especially to screw bearings, gearbox, and critical moving parts.

✔ Clean the surrounding area

Plastic pelletizing generates dust and residues.

• Clean the machine surface, feed inlet, and pelletizer cutter area.

• Prevent contaminants from entering the barrel, which can damage the screw and reduce pellet quality.

✔ Inspect the electrical system

• Check whether wiring inside the control cabinet is loose.

• Ensure the emergency stop, temperature controller, ammeter, and other meters operate properly.

• Inspect heater band terminals for oxidation.

✔ Monitor the temperature curve

Different plastics (PP, PE, ABS, etc.) require different temperature settings.

If any zone shows sudden deviation:

• Possible cause: heater failure or thermocouple damage

• Consequence: material degradation, discoloration, or barrel blockage

Stop production and check immediately.

2. Scheduled Preventive Maintenance (The Root Solution)

Daily checks solve surface problems, but deep maintenance prevents long-term failures.

Set maintenance cycles based on actual machine usage.

✔ Hydraulic system (Monthly)

• Check oil level and refill to the standard mark.

• Replace hydraulic filter cartridges to remove impurities.

• Inspect for oil leakage; replace seals or hoses if needed.

✔ Screw and barrel (Quarterly)

• Measure screw diameter; if wear exceeds 0.5 mm, repair or replace it.

• Check screw–barrel clearance; excessive clearance causes poor plasticizing and inconsistent pellet quality.

✔ Gearbox (Every 6 Months)

• Replace gear oil and clean internal impurities.

• Inspect gear mesh conditions.

• If abnormal noise or vibration occurs, repair immediately.

✔ Electrical system (Annually)

• Clean dust from the control cabinet.

• Inspect contactors and relays for oxidation; polish or replace them.

• Calibrate temperature controllers and ammeters to ensure accurate readings.

3. Emergency Troubleshooting Guide

Even with good maintenance, unexpected issues may occur.

Follow these steps carefully to prevent secondary damage.

1) Material blockage (Jamming)

• Stop machine immediately and turn off heating.

• When barrel temperature drops below 100°C, remove the feed inlet.

• Use a push rod to slowly remove the blocked material—NEVER hammer the barrel, it may deform.

• Check screw straightness; repair or replace if bent.

2) Excessive pellet contamination

Check in this order:

1.Raw materials – ensure they are clean and free of foreign particles.

2.Barrel/screw residue – clean carbonized deposits following shutdown procedures.

3.Pelletizer screen – if damaged, replace the screen to prevent impurities entering the pellets.

3) Motor overheating

If surface temperature exceeds 80°C:

• Cut power immediately to prevent motor burnout.

• Check whether bearings lack lubrication or are worn out.

• Inspect feeding speed—overfeeding can overload the motor.

• Resume production only after cooling and correcting the cause.

Final Thoughts

A plastic pelletizing machine will serve you for many years if you maintain it correctly.

Through daily checks, scheduled preventive care, and proper emergency handling, you can:

• Reduce downtime

• Lower repair costs

• Improve pellet quality

• Extend machine lifespan

• Boost production stability and profitability

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