How Long After Drying a Hot Runner Can It Be Put into Production Directly?

I. Standard Waiting Period

Use situation: the hot runner has finished all baking procedures as per specification. After drying, the insulation resistance is steady at the level of ≥20MΩ, and the temperature rise curve is fully normal.

Direct Production Waiting Time Wiring and installation can be performed within 1 hour after cooling below 60℃. Once you reach the production temperature you may immediately start the production. You don't have to wait.

II. Waiting times for various moisture levels

Slightly Moist Hot Runner: Dry and cool to room temperature. Do complete retesting and visual inspection of insulation within 30 minutes. When conformity has been established, it can be put in the machine and promptly launched into production after heating. Total wait time under 1.5 hours.

Moderately Moist Hot Runner Allow Natural Cooling 1 Hour After Drying. Re-test insulating resistance and drop to no Complete wiring Heat to + 100 ° C 30 minutes Heat to the production temperature Total wait time ≤ 2 hours. Heavy Moisture Hot Runner: Natural cooling for 1.5 hours after drying. Increase the temperature to 100℃, hold for 1 hour after two consecutive retests with insulation resistance ≥50MΩ. Then gradually bring the temperature up to production. Total waiting time should be ≤3 hours.

III. Rules for Adjusting Time in Special Cases

In high humidity environment like rainy season/humid weather, keep temperature at 100℃ for 30 minutes after drying and installation to avoid additional moisture absorption during cooling before rising to production temperature.

For large multi-cavity hot runner systems, after drying and heating to production temperature, maintain the temperature for another 30 minutes to ensure the temperature is uniform across the whole runner before beginning direct production.

If the insulating resistance is decreasing slowly after drying, increase the holding duration to 120℃ for 1 hour for dehumidification. Only after retesting the insulating resistance to be qualified can you go to the production stage.

IV. Final Conditions of Startup Confirmation

After the hot runner reaches the production temperature, retest the high-temperature insulation resistance, which should be ≥0.1MΩ. Confirm that the temperature measurement variation of all sensors is ≤±1℃. Production can be begun straight after the aberrant alarms disappear.