How to Adjust PID Parameters Based on Hot Runner Characteristics

According to the earlier works on PID tuning and fast parameter matching for the hot runner temperature monitoring systems, the PID parameters can be tuned in a specific way according to the thermal properties of the hot runner in different regions:

Nozzle Region (Low Thermal Inertia): Nozzles are small and heat up quickly, hence they tend to overshoot. To suppress temperature overshoot set the proportional gain (P) to 20-30, the integral gain (I) to 30-60s, and the derivative gain (D) to 5-15s.

Manifold Region (Large Heat Capacity) Manifolds are large with high thermal inertia. Set the proportional gain (P) to 40-60, the integral gain (I) to 60-120s and the derivative gain (D) to 15-30s to eliminate steady-state temperature variations.

Special Thick-Walled Hot Runners: For thick-walled hot runners with ultra-large heat capacity, extend the integral time further, and limit the proportional gain appropriately to avoid temperature drift caused by longtime heating.

The temperature precision of the whole hot runner system may be stabilized within ±1℃ after the regional differentiation adjustment.