Causes and Analysis of 11 Kinds of Twin Screw Extruders

1, the main motor can not start

Reason 1: The driving procedure is wrong.

Treatment: Check the procedure and drive again in the correct driving order.

Cause 2: There is a problem with the main motor thread, and the fuse is burned.

Treatment method: Check the main motor circuit. Check that the lubricant pump is activated and check the status of the interlock associated with the main motor. After the inverter's induction power is not discharged, turn off the main power and wait for 5 minutes before starting. Check if the emergency button is reset.

2, the main motor makes an abnormal sound

Cause 1: The main motor bearing is damaged.

Treatment method: Replace the main motor bearing.

Cause 2: A thyristor in the main motor thyristor rectifier circuit is damaged.

Treatment method: Check the thyristor rectifier circuit and replace the thyristor component if necessary.

3, the host current is unstable

Cause 1: Feeding is uneven.

Treatment: Check the feeder to troubleshoot.

Cause 2: The main motor bearing is damaged or poorly lubricated.

Treatment method: Repair the main motor and replace the bearing if necessary.

Cause 3: A certain heater failed and did not heat up.

Treatment: Check that each heater is working properly and replace the heater if necessary.

Cause 4: The screw adjustment pad is incorrect, or the phase is incorrect, and the component interferes.

Treatment method: Check the adjustment pad, pull out the screw to check the screw for interference.

4, the pressure on the head is unstable

Cause 1: The main motor speed is not uniform.

Treatment method: Check the main motor control system and bearings.

Reason 2: The feeding motor speed is not uniform and the feeding amount fluctuates.

Treatment: Check the feeding system motor and control system.

5, the main motor bearing temperature rise is too high

Cause: The bearing is not well lubricated. Bearing wear is severe.

Treatment: Check and add lubricant. Check the motor bearings and replace if necessary.

6, the machine head is not smooth or blocked

Reason 1: The heater does not work for a certain period, and the material is not plasticized.

Treatment: Check the heater and replace if necessary.

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

Treatment method: verify the set temperature of each section, and negotiate with the technician if necessary to increase the temperature setting.

Reason 3: There may be foreign matter that is not easily melted.

Treatment: Clean and inspect the extrusion system and the machine head.

7, the amount of extrusion suddenly dropped significantly

Cause 1: The feeding system has failed or the material in the hopper has not been fed.

Treatment: Check the feed system or the level of the hopper.

Cause 2: The extrusion system enters the hard object to catch the screw, so that the material cannot pass.

Treatment: Check the cleaning system.

8, the main power start current is too high

Cause: The heating time is insufficient and the torque is large. A certain heater does not work.

Treatment method: Apply the hand truck when driving. If it is not easy, extend the heating time or check whether the heaters are working properly.

9, low pressure of lubricating oil

Cause 1: The pressure regulator valve pressure setting value of the lubricating oil system is too low.

Treatment: Check and adjust the pressure system of the lubricating oil system.

Cause 2: The oil pump is faulty or the suction pipe is blocked.

Treatment method: Check the oil pump and suction pipe.

10, automatic screen changer is slow or not working

Cause 1: The air pressure or oil pressure is low.

Treatment method: Check the power system of the screen changer.

Cause 2: The cylinder (or hydraulic cylinder) is leaking (or leaking).

Treatment method: Check the sealing of the cylinder or hydraulic cylinder.

11, the safety pin or safety key is cut off

Cause: Excessive torque in the extrusion system.

Treatment Method 1: Check if the extrusion system has metal or the like entering the stuck screw.

Treatment method 2: At the beginning, check whether the preheating temperature rise time or temperature rise value meets the requirements.