1. Effects of High Humidity Environments (Relative Humidity > 70%)
Sharply Reduced Drying Efficiency: High moisture content in the air inhibits the evaporation of moisture from the can surface, making hot air drying or natural air drying ineffective.
Prone to Rewetting: Even if the surface appears dry, condensation may occur after cooling due to the ambient dew point being higher than the metal surface temperature, leading to pitting corrosion.
Increased Risk of Rust: In humid air, visible rust spots can appear on the cleaned active metal surface within 6-12 hours; in rainy weather or coastal areas, rust may even reappear within 1 hour.
2. Ideal Drying Environment Parameters
Relative humidity should be controlled below 60%, combined with hot air drying at 120-170℃ for 10-20 minutes to ensure thorough drying of the inner wall.
If infrared drying is used, it can be completed in 2 minutes at 60-70℃, but ambient humidity still needs to be controlled simultaneously to avoid subsequent contamination.
3. Practical Measures to Combat High Humidity
Use Industrial Dehumidifiers: Equip drying rooms or storage areas with dehumidifiers to stably control relative humidity within a safe range.
Nitrogen Purging Protection: After drying, introduce dry nitrogen to create an inert atmosphere and prevent moisture contact.
Sealed Packaging + Desiccant: Immediately pack the product into VCI rust-proof bags and add silica gel desiccant for double protection.
✅ Recommended Operating Procedure: Cleaning → Compressed Air Drying → Hot Air Drying (120℃/15min, Humidity <60%) → Cooling → Spraying Water-Based Rust Inhibitor → Sealed Packaging. This process can control the rust return rate to within 1%.
