Troubleshooting for Motor Failures in Plastic Pelletizers

Plastic pelletizers are crucial machines for eliminating white pollution and achieving the recycling of waste plastics. Such important machinery requires special care to avoid malfunctions that could disrupt production. However, plastic pelletizers sometimes experience malfunctions. Let's look at what to do when the motor, a critical component, fails.

Analysis of Causes for Excessive Main Motor Torque: Malfunctions in the oil lubrication system, misalignment between the main motor output shaft and the gearbox input/output shaft, and vibrations in the motor and clutch can all damage the main motor bearings, leading to excessive torque. Additionally, excessive feeding load or poor material melting can also cause excessive main motor torque.

Solutions: Regularly inspect and clean the lubrication system. Use a vibration meter and infrared thermometer to measure the main motor bearings and generate a trend chart. If the value exceeds the trend value, measure the main motor's idle current or power value to determine if the bearing needs replacement. Regularly check the alignment between the main motor output shaft and the gearbox input shaft. This alignment check is mandatory after the initial start-up or three months of operation after bearing replacement.

Conduct electrical tests to determine the cause of rotor imbalance; perform vibration speed tests on the clutch, and readjust the dynamic balance if it exceeds the specified value. Regularly inspect the cylinder heating and cooling systems to ensure uniform heating and complete melting of the material. If the main motor power curve and melt pressure curve increase instantaneously at the moment the extruder starts, it indicates that the feed rate of the feeding system is too high instantaneously, and the feed rate should be reduced.