Views: 0 Author: Site Editor Publish Time: 2026-07-30 Origin: Site
Electrical system failures often cause the entire extrusion line to shut down, and troubleshooting them can be extremely time-consuming. Make it a daily priority to check the following:
Verify that the cooling fans on the control cabinet are running smoothly and ensure the internal temperature is not excessively high.
Check the inverter (VFD) panels for any flashing alarm codes or fault warnings.
Inspect the junction box covers on both the main motor and the feeder motor to ensure they are tightly sealed, preventing conductive dust from entering and causing short circuits.
Temperature fluctuations are frequently caused by loose thermocouples rather than damaged heater bands. Every day, verify that the thermocouple in each heating zone is firmly inserted into its measurement hole and that the securing screws are tight. Observe the deviation between the actual temperature and the set value on the controller; a normal variance should be within ±5°C.
Check for thermocouple short circuits. If the temperature controller displays abnormally high readings or rapidly jumping values, the thermocouple may be short-circuited. Confirm this by measuring its resistance with a multimeter and replace it immediately if confirmed.
If a specific heating zone heats up remarkably slowly, use a clamp meter to measure the current. If there is no current reading, the heater band is burnt out and requires immediate replacement.
Check the gearbox oil level daily. The sight glass should show the oil level between 1/2 and 2/3 full, and the oil should be a transparent amber color. An oil level that is too low leads to dry grinding of the gears and bearings, causing rapid destruction. Conversely, an oil level that is too high causes poor heat dissipation, raising the oil temperature and destroying its viscosity.
Inspect the oil seals and all gearbox joint surfaces for any traces of leakage.
Listen to the oil pump for abnormal noises and verify that the inlet and outlet pressures are within the standard operating range.
Check the water cooling connectors to ensure there are no leaks, the cooling water circuit is unobstructed, and all joints are tight.
Critical Warning: If the oil turns a milky white color, the internal cooler is leaking water. If the oil turns black and contains metallic dust, the gears are experiencing abnormal, severe wear. In both scenarios, you must stop the machine immediately for a full overhaul.
The connection flanges between the screws and barrels, as well as the joint surfaces between the die head and the machine body, are high-risk areas for melt leakage. Operators must check these connection points daily for any signs of polymer seepage.
For minor leaks, attempt to safely tighten the surrounding bolts while the machine is at operating temperature.
For severe leaks, the machine must be shut down, disassembled, and thoroughly cleaned to inspect whether the sealing gaskets are aged or damaged. Replace them if necessary.
Ignoring long-term leaks not only wastes raw materials but also allows carbonized polymer to encase and destroy the heater bands, completely ruining your temperature control accuracy.
When operating normally, the equipment should produce a stable, low-frequency hum. If any of the following abnormal sounds or vibrations occur, it indicates a hidden mechanical threat:
Periodic "clunking" sounds: This indicates severe wear on the screw's non-return valve (check ring) or foreign metal debris trapped inside the barrel.
High-frequency screeching: The gap between the pelletizer cutter blades and the die plate is too tight, or a bearing is running dry without lubrication.
Violent shaking of the entire machine: This points to coupling misalignment between the motor and gearbox, or a bent feeder screw shaft.
Gearbox grinding noises: Indicates internal bearing wear that requires immediate replacement.
Main motor rattling: Likely a damaged motor bearing that must be swapped out to prevent motor failure.
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