What is the reason for unstable extruder temperature control?

1. Temperature sensor failure
The sensor is damaged, aged or has decreased accuracy, and the actual temperature cannot be accurately measured.
For example, the sensor's thermistor fails, resulting in incorrect temperature readings.
2. Heating or cooling element failure
The heating wire is burned out, short-circuited, the cooling fan fails, the cooling pipe is blocked, etc., causing abnormal heating or cooling effects.
For example, if the heating wire is partially disconnected, it will cause insufficient local heating.
3. Temperature control system failure
The controller's program is wrong, the hardware is damaged, or the PID parameter setting is unreasonable.
If the PID parameters do not match the actual system, it may cause excessive temperature fluctuations.
4. Power supply problem
Unstable voltage and poor contact of the power supply line affect the power output of the heating element.
For example, a sudden drop in voltage will reduce the heating power and cause the temperature to drop.
5. Changes in material properties
The composition, water content, viscosity, etc. of the material have changed significantly, resulting in different heat required for plasticization.
If the batch of plastic raw materials is suddenly changed, the performance difference may affect temperature control.
6. Screw wear
The gap between the worn screw and the barrel increases, and the shear and friction heat of the material changes, affecting the temperature.
The actual heat generated may be reduced, resulting in low temperature.
7. Ambient temperature changes
The ambient temperature of the production workshop fluctuates greatly, affecting the heat dissipation or heat absorption of the extruder.
Especially in workshops without good temperature regulation, high temperatures in summer and low temperatures in winter will interfere with the temperature of the extruder.
8. Mechanical failure
Problems with the transmission parts and bearings of the extruder cause the screw speed to be unstable, thereby affecting heat generation.
For example, a loose transmission belt will cause the screw speed to be fast and slow.
9. Poor insulation effect
The insulation layer of the barrel is damaged or aged, and the heat is lost too quickly or the external heat is easily transmitted.
For example, the insulation material is damaged, which increases the heat dissipation of the barrel and makes it difficult to keep the temperature stable.