Industry Dynamic

Common fault causes and treatment methods of extruder


1、 The current of extruder host is unstable

Cause of failure:

(1) The feed is not uniform.

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

(3) The heater of a certain section fails to heat.

(4) Screw adjustment point is not correct, or the phase is not correct, components interference.

Treatment method:

(1) Check the feeder and remove the trouble.

(2) Repair the main motor and replace the bearing if necessary.

(3) Check whether the heater works normally and replace the heater if necessary.

(4) Check the adjusting pad, pull out the screw and check whether the screw has interference.

2、 The main motor of extruder cannot be started

Cause of failure:

(1) There was a mistake in the starting procedure.

(2) There is a problem with the thread of the main motor and whether the fuse is burnt out.

(3) The interlocking device related to the main motor works.

Treatment method:

(1) Check the program and restart in the correct order.

(2) Check the main motor circuit.

(3) Check whether the lubricating oil pump is started, and check the status of the interlocking device related to the main motor.The oil pump doesn't work and the motor doesn't work.

(4) Check whether the emergency button is reset.

(5) If the induction power supply of the inverter is not discharged, turn off the main power supply and wait for 5 minutes to start.

3、 The discharge of extruder head is blocked or blocked

Cause of failure:

(1) A section of the heater is not working, and the material plasticization is poor.

(2) The operating temperature is set too low, or the molecular weight distribution of plastics is wide and unstable.

(3) There may be foreign bodies that are not easy to melt.

Treatment method:

(1) Check heater and replace if necessary.

(2) If necessary, check the set temperature with the process personnel.

(3) Clean and check extrusion system and head.

4、 The main electric starting current of extruder is too high

Cause of failure:

(1) Insufficient heating time and high torque.(2) A section of heater does not work.

Treatment method:

When driving, use hand turning gear. If it is not easy, extend heating time or check whether each section of heater works normally.

5、 The main motor of extruder makes abnormal sound

Cause of failure

(1) The main motor bearing is damaged.(2) One of the thyristor rectifying circuits of the main motor is damaged.

Treatment method:

(1) Replace the main motor bearing.(2) Check the silicon controlled rectifier circuit and replace the silicon controlled element if necessary.

6、 Too high temperature rise of main motor bearing of extruder

Cause of failure:

(1) Poor bearing lubrication.

(2) The bearing is seriously worn.

Treatment method:

(1) Check and add lubricant.

(2) Check the motor bearing and replace it if necessary.

7、 The pressure of extruder head is unstable

Cause of failure:

(1) The speed of main motor is uneven.

(2) The speed of feeding motor is uneven, and the feeding quantity fluctuates.

terms of settlement

(1) Check the main motor control system and bearings.

(2) Check the feeding system motor and control system.

8、 Low lubricating oil pressure of extruder

Cause of failure:

(1) The pressure setting value of pressure regulating valve of lubricating oil system is too low.(2) Failure of oil pump or blockage of oil suction pipe.

Treatment method:

(1) Check and adjust the pressure regulating valve of lubricating oil system.(2) Check the oil pump and suction pipe.

9、 The speed of automatic screen changing device of extruder is slow or ineffective

Cause of failure:

(1) Low air pressure or oil pressure.

(2) Air leakage (or oil leakage) of cylinder (or hydraulic station)

Treatment method:

(1) Check the power system of the screen changer.

(2) Check the sealing condition of cylinder or hydraulic cylinder.

10、 Extruder safety pin or safety key cut off

Cause of failure:

(1) The torque of extrusion system is too high.

(2) The connection between the main motor and the input bearing is not concentric

Treatment method:

(1) Check whether the extrusion system has metal and other things entering into the stuck screw.At the beginning, check whether the preheating time or heating value meet the requirements.

(2) Adjust the main motor.