I. Drying Time for Slightly Damp Hot Runners
Dampness Judgment Criteria: The hot runner is exposed to a humid environment for 2-4 hours, with an insulation resistance between 1-5 MΩ and no obvious condensation.
Total Drying Time: 12 hours
Segmented Time Allocation: 80℃ low-temperature preheating for 3 hours → 120℃ medium-temperature dehumidification for 7 hours → 160℃ high-temperature curing for 2 hours
Drying Verification Standard: Insulation resistance is retested twice consecutively at 1-hour intervals, ≥20 MΩ, and the value remains stable without any increase, confirming that the moisture has been completely removed.
II. Drying Time for Moderately Damp Hot Runners
Dampness Judgment Criteria: The hot runner surface has slight water mist, and the insulation resistance is between 0.1-1 MΩ. It is exposed to a high-humidity environment for 4-8 hours.
Total drying time: 16-18 hours
Segmented time allocation: 80℃ low-temperature preheating for 4 hours → 120℃ medium-temperature dehumidification for 10-12 hours → 160℃ high-temperature curing for 2 hours
Drying verification standard: No obvious temperature rise stagnation at the 100℃ node, no continuous moisture overflow throughout the process, and stable insulation resistance ≥30MΩ.
III. Drying time for heavily damp hot runners
Dampness judgment criteria: Obvious condensation/water ingress marks on the surface of the hot runner, insulation resistance <0.1MΩ, prolonged exposure to a high humidity environment.
Total drying time: 20-24 hours
Segmented time allocation: 80℃ low-temperature preheating for 4 hours → 120℃ medium-temperature dehumidification for 14-18 hours → 160℃ high-temperature curing for 2 hours
Drying verification standard: The temperature rise curve fully recovers to normal, there is no prolonged temperature stagnation plateau at 100℃, and stable insulation resistance ≥50MΩ.
IV. Special Scenario Duration Adjustment Rules
For hot runner systems operating in high humidity environments such as the plum rain season/return to spring, an additional 2 hours of 120℃ dehumidification time should be added to the corresponding duration to prevent residual moisture.
For large hot runner systems with built-in heaters, the medium-temperature dehumidification time should be extended by 20% to ensure complete removal of moisture from deep gaps in the runner plates.
During the drying process, baking can be terminated early if the insulation resistance remains stable at ≥20MΩ for two consecutive tests; the full duration is not required.
