Overview

Screw failure is a common problem in waste plastic granulators and can directly affect plasticizing performance, output stability and machine service life. Two typical issues are severe vibration at the front part of the barrel when the screw retreats, and the screw not retreating during plasticization. Both problems are usually related to mechanical wear, loose parts, temperature control faults or improper pressure adjustment.

Why Does the Screw Not Retreat During Plasticization?

If the screw does not retreat while the waste plastic granulator is plasticizing material, the fault may be related to barrel temperature control, material feeding, backpressure adjustment or hydraulic control components. This problem can stop normal production and should be diagnosed step by step.

Main Causes

The barrel temperature is too low or the temperature controller is faulty, causing poor plasticization and high material viscosity

The screw drive motor is overloaded and cannot start

The hopper is empty or the feeding port is blocked

The backpressure valve is not adjusted properly, making screw backpressure too high

The solenoid valve coil for pre-plastic control is burned out

The reversing valve is damaged or not working properly

Treatment Methods

Check whether the actual barrel temperature is too low and whether the displayed temperature matches the real temperature inside the barrel. If the temperature control system is faulty, repair or replace it in time. Make sure the hopper has enough material and the feeding port is not blocked. Adjust the backpressure to a proper level, and inspect the reversing valve and solenoid valve coil for damage or failure. Replace any worn or damaged parts as needed.

Waste Plastic Granulator Video:

Treatment Methods

Check whether the actual barrel temperature is too low and whether the displayed temperature matches the real temperature inside the barrel. If the temperature control system is faulty, repair or replace it in time. Make sure the hopper has enough material and the feeding port is not blocked. Adjust the backpressure to a proper level, and inspect the reversing valve and solenoid valve coil for damage or failure. Replace any worn or damaged parts as needed.

Conclusion

Screw failure in a waste plastic granulator is often caused by a combination of mechanical wear, control system faults and improper adjustment. Regular inspection, correct installation and timely maintenance can reduce downtime, improve granulation efficiency and extend the service life of the machine.

FAQ

Q1: Why does the front of the barrel vibrate when the screw retreats?

A: It is usually caused by worn bearings, loose barrel bolts or a loose screw head.

Q2: Why does the screw not retreat during plasticization?

A: Common causes include low barrel temperature, feeding problems, excessive backpressure or faulty control valves.

Q3: How can screw failure be prevented?

A: Regular inspection, proper tightening, stable temperature control and timely replacement of worn parts can help prevent failure.

Q4: What should be checked first if the screw does not retreat?

A: Check barrel temperature, material feeding, backpressure setting and the condition of the reversing valve and solenoid valve.