I. Standard Cooling-Down Start-up Time for Typical Scenario
Applicable Conditions: The hot runner has completed the entire baking process according to specifications. After drying, the insulation resistance is stable at ≥20MΩ, and the temperature rise curve is completely normal without any abnormalities.
Total Cooling-Down Start-up Time: Natural cooling to below 60℃ takes 1~1.5 hours. After completing wiring and installation, heat to the production temperature. Once the parameters are confirmed to be normal, production can begin directly.
II. Cooling-Down Start-up Time for Different Moisture Levels
Slightly Moist Hot Runner: After drying, cool for 30 minutes. Retest the insulation resistance; if there is no drop, complete wiring and heat to the production temperature before starting up. Total time ≤1.5 hours.
Moderately Moist Hot Runner: After drying, allow natural cooling for 1 hour. Retest the insulation resistance; if it is stable and meets the standard, heat to 100℃ and hold for 30 minutes. Then heat to the production temperature before starting up. Total time ≤2 hours. Severely Moisturized Hot Runner: After drying, allow natural cooling for 1.5 hours. Repeat insulation resistance measurements twice; if the insulation resistance is ≥50MΩ, raise the temperature to 100℃ and hold for 1 hour. Gradually raise the temperature to the production temperature before starting the machine. Total time ≤3 hours.
III. Cooling and Start-up Adjustment Rules for Special Environments
In high-humidity environments such as the rainy season/humid season, the cooling process must be completed in the drying room. The cooling time is uniformly shortened to 45 minutes to avoid prolonged exposure and secondary moisture absorption. Then raise the temperature to the production temperature before starting the machine.
For large multi-cavity hot runner plates, add an extra 30 minutes to the cooling time to ensure the internal temperature of the runner plate drops uniformly to below 60℃, preventing burns to installation personnel. Afterward, the machine can be started after heating.
Forced cooling methods such as direct fan blowing and water cooling are prohibited to avoid sudden cooling deformation of the hot runner metal components, which could lead to sensor displacement, sealing surface leakage, and prolonged subsequent debugging and start-up time.
IV. Final Confirmation Conditions Before Start-up
After the hot runner reaches the production temperature, retest the high-temperature insulation resistance to ensure it is ≥0.1MΩ, the temperature deviation of all sensors is ≤±1℃, and there are no abnormal alarms. Then, the machine can be officially started for production.
