Extruder fault repair and maintenance

Plastic extruder is a common plastic machinery. In the process of daily operation of the extruder, there are various failures in the extrusion machine, which affects the normal production of plastic machinery. Below we analyze the failure of the extruder.

Plastic extruder failure analysis: host current is unstable

1. Production reasons:

(1) Feeding is uneven.

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

(3) A certain heater fails and does not heat up.

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

2, the processing method:

(1) Check the feeder to troubleshoot.

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

(3) Check that each heater is working properly and replace the heater if necessary.

(4) Check the adjustment pad and pull out the screw to check whether the screw has interference.

Plastic extruder failure analysis: the main motor can not start

1, the cause:

(1) The driving procedure is wrong.

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

(3) The interlocking device associated with the main motor functions

2, the processing method:

(1) Check the procedure and drive again in the correct driving order.

(2) Check the main motor circuit.

(3) Check if 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 be turned on.

(4) After the inverter's induction power is not discharged, turn off the main power and wait for 5 minutes before starting.

(5) Check if the emergency button is reset.

Plastic extruder failure analysis: the machine head is not smooth or blocked

1, the cause:

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

(2) The operating temperature setting is low, or the molecular weight distribution of the plastic is wide and unstable.

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

2, the processing method:

(1) Check the heater and replace if necessary.

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

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

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

1, the cause:

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

(2) A certain heater does not work.

2, the processing method:

(1) Apply the hand truck when driving. If it is not easy, extend the heating time or check whether the heaters are working properly.

Plastic extruder failure analysis: The main motor emits an abnormal sound:

1, the cause:

(1) The main motor bearing is damaged.

(2) A thyristor in the main motor thyristor rectifier circuit is damaged.

2, the processing method:

(1) Replace the main motor bearing.

(2) Check the thyristor rectifier circuit and replace the thyristor component if necessary.

Plastic extruder maintenance

1. The plastic extruder equipment [2] should be placed in the ventilation position to ensure the heat dissipation of the motor and prolong its life; the machine should be well grounded.

2. Regularly check the tool screw. After using the new machine for 1 hour, use the tool to fasten the moving knife and fix the knife's screw to strengthen the fixing between the blade and the tool holder. The lubricating oil should be added regularly to ensure the lubrication between the bearings. In order to ensure the sharpness of the tool cutting, the tool should be inspected frequently to ensure its sharpness and reduce unnecessary damage of other parts due to the blunt blade; periodically check whether the belt is slack and adjust it in time.

3. Restart - Before the second start, the remaining material in the machine room should be removed first, and the starting resistance should be reduced. The inertia cover and the pulley cover should be opened periodically to clear the ash outlet under the flange, because the crusher chamber is discharged. Powder into the shaft bearing.

4. Replacement parts--When changing the tool, the gap between the movable knife and the fixed knife: 0.8MM for the crusher above 20HP is better, 0.5MM for the crusher below 20HP is better. The thinner the recycled material, the smaller the gap can be adjusted.