Causes and solutions of common failures of plastic extruders

Plastic extruder is a common plastic machinery and equipment. During the daily operation of the extruder, various faults may occur in the extruder, which affects the normal production of plastic machinery. The following are the causes and solutions for extruder failures:

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Plastic extruder failure analysis: main extruder current unstable

1. Cause:

(1) Uneven feeding.

(2) A certain section of heater fails and does not heat.

(3) The main motor bearing is damaged or poorly lubricated. ​

(4) The screw adjustment pad is wrong, or the phase is wrong, and the components interfere.

2. Processing method:

(1) Check the feeder and troubleshoot.

(2) Inspect the main motor and replace the bearings if necessary.

(3) Check the adjustment pad, pull out the screw and check whether there is any interference with the screw.

(4) Check whether each heater is working properly and replace the heater if necessary.

Plastic extruder failure analysis: main motor cannot start

1. Cause:

(1) The driving procedure is wrong.

(2) The interlocking device related to the main motor works

(3) There is a problem with the main motor thread, and whether the fuse wire is burned.

2. Processing method:

(1) Check the main motor circuit.

(2) Check whether the emergency button is reset.

(3) Check the procedures and drive again according to the correct driving sequence.

(4) The induction power of the inverter has not been discharged completely. Turn off the main power supply and wait for 5 minutes before starting it again.

(5) Check whether the lubricating oil pump is started and check the status of the interlocking device related to the main motor. The oil pump does not turn on and the motor cannot turn on.

Plastic extruder failure analysis: the extruder head discharging not smoothly or blocked

1. Cause:

(1) There may be foreign matter that is not easily melted.

(2) A certain section of the heater does not work and the material is poorly plasticized.

(3) The operating temperature is set too low, or the molecular weight distribution of the plastic is broad and unstable. ​

2. Processing method:

(1) Check the heater and replace if necessary.

(2) Verify the set temperature of each section, and negotiate with the technician if necessary to increase the temperature set value.

(3) Clean and inspect the extrusion system and machine head.

Plastic extruder failure analysis: main motor starting current is too high

1. Cause:

(1) A certain section of heater does not work.

(2) The heating time is insufficient and the torque is large.

2. Processing method:

(1) Extend the heating time or check whether the heaters in each section are working properly.

Plastic extruder failure analysis: the main motor makes abnormal noise

1. Cause:

(1) The main motor bearing is damaged.

(2) One of the thyristors in the main motor thyristor rectifier circuit is damaged.

2. Processing method:

(1) Replace the main motor bearings.

(2) Check the silicon controlled rectifier circuit and replace the silicon controlled components if necessary.