I. Adjusting Heating Strategy by Number of Chambers
Single/2-Cavity Small Hot Runner: Heating rate set to 3-4℃/min, allowing 100% full power output throughout.
Each holding period is set to 10 minutes, reducing the total heating time to 30-45 minutes.
4-8-Cavity Medium Hot Runner: Heating rate set to 2-3℃/min, full power output before 100℃, power limited to 80% after 100℃.
Each holding period is set to 15 minutes, controlling the total heating time to 50-75 minutes.
16-32-Cavity Large Multi-Cavity Hot Runner: Heating rate set to 1.5-2℃/min, full power output before 120℃, power limited to 70% after 120℃.
Each holding period is set to 20 minutes, controlling the total heating time to 90-120 minutes.
For ultra-large multi-cavity hot runner systems with 64 or more cavities: The heating rate is set to 1~1.5℃/min. Before reaching 120℃, the system operates in two staggered full-power phases. After 120℃, the power is limited to 60%.
Each of the two holding periods is set to 30 minutes, with the total heating time controlled between 150~180 minutes.
II. Adjusting Heating Strategies Based on Material:
For thermally stable general-purpose materials such as PP/PE: Increase the heating rate for all cavities by 20% and shorten the holding time by 30% to maximize the reduction of heating time.
For materials with moderate thermal stability such as PC/PA66: Retain the baseline heating parameters. Increase temperature monitoring frequency after the temperature exceeds 300℃ to prevent localized overheating and degradation.
For easily degradable and sensitive materials such as PVC/POM: Decrease the heating rate for all cavities by 30% and increase the holding time by 50%. Perform temperature checks every 5 minutes after the temperature exceeds the safety threshold to eliminate the risk of material degradation.
III. Adjusting Heating Strategies Based on Environment and Operating Conditions
High Humidity (Plum Rain) Environment: All chambers will have an additional 10 minutes of dehumidification and heat preservation at the 100℃ stage to ensure sufficient moisture removal and prevent subsequent material hydrolysis and degradation.
Non-Production Standby Scenarios: The hot runner will be kept at a low-temperature standby state of 80~100℃. The next startup will not require starting from room temperature, directly reducing heating time by more than 50%.
Hot Runner Overhaul/New Installation Scenarios: The interval between the first two heating stages will be shortened by 50% to verify the stability of the temperature control system. Only after confirming there are no abnormalities will the system switch to the regular heating strategy.
IV. Dynamic Closed-Loop Adjustment Mechanism
The temperature control system will record data throughout the entire process. By comparing historical standard heating curves, abnormal temperature points will be identified, and parameters such as heating rate and heat preservation time will be continuously iterated and optimized.
If a temperature fluctuation exceeds ±3℃, heating will be immediately paused to investigate faults such as sensor displacement and PID parameter mismatch. Heating will only resume after these issues are resolved to prevent process abnormalities.
