To improve the ventilation and moisture resistance of UV metal coatings, comprehensive measures need to be taken from three aspects: environmental control, equipment optimization, and construction management. The following are specific solutions:
1、 Ventilation effect improvement plan
1. Optimization of ventilation system design
Local exhaust strengthening:
Set up a closed gas collection hood at the spraying station, using a down suction or side suction design, with a capture efficiency of 90%, to ensure timely extraction of solvent volatiles and moisture.
The exhaust duct is made of stainless steel material to prevent residual corrosion of paint, and the slope of the duct is 1% to prevent the accumulation of condensed water.
Overall air supply regulation:
Use a variable frequency fan to control the air supply volume and dynamically adjust the wind speed according to the construction stage (such as spraying, leveling, and curing) (it is recommended to adjust the wind speed during the leveling stage to 0.3m/s).
Install an air filtration device (with a filtration efficiency of 95%) at the air supply outlet to reduce the entry of dust into the construction area.
Airflow organization simulation:
Optimize the layout of air supply and exhaust through CFD simulation to avoid airflow short circuits or dead corners, ensuring uniform wind speed in the work area (0.1m/s).
2. Auxiliary ventilation measures
Mobile ventilation equipment:
During the construction of large workpieces, use axial flow fans or mobile exhaust cabinets to enhance ventilation in specific areas.
Construction period selection:
Avoid peak humidity periods in the morning and evening, and prioritize key processes such as curing in the afternoon when humidity is low.
Wind speed monitoring and feedback:
Install wind speed sensors in the work area, connect real-time monitoring data to the PLC control system, and automatically adjust the frequency of the fan.
2、 Moisture proof effect improvement plan
1. Environmental humidity control
Dehumidification equipment configuration:
Install a rotary dehumidifier (dew point temperature≤ -40 ℃) or a refrigerated dehumidifier (suitable for humidity≤ 80% scenarios) to stabilize the ambient humidity at 40% -60%.
For high humidity areas (such as coastal areas), a two-stage dehumidification system (freezing+rotary combination) is used to ensure dehumidification efficiency.
Substrate pretreatment:
Before construction, bake and dehumidify the metal substrate (temperature 80-100 ℃, time 30-60 minutes) to achieve a moisture content of 2%.
Use infrared heating lamps to quickly dehumidify local areas and avoid excessive energy consumption caused by overall baking.
Paint storage management:
The paint warehouse is equipped with a constant temperature and humidity cabinet (temperature 20-25 ℃, humidity≤ 50%), and the paint bucket adopts a double-layer sealed design with a desiccant package added to the inner layer.
2. Moisture prevention during construction
Moisture isolation measures:
Lay moisture-proof film (thickness: 0.2mm) on the ground of the construction area, and apply moisture-proof coating (such as epoxy moisture-proof paint) on the walls.
Use construction tents with good air tightness to create an independent microenvironment and reduce the intrusion of external moisture.
Curing process optimization:
Install a nitrogen protection device on the UV curing equipment to reduce the oxygen concentration (1%) in the curing area and isolate moisture.
Adopting segmented curing process: pre curing with low energy density (50-80W/cm²) first, and then fully curing with high energy density (120-150W/cm²) to reduce moisture penetration time.
Real time humidity monitoring:
Install temperature and humidity sensors in the work area, synchronize data to mobile terminals, and automatically trigger an alarm and suspend construction when the humidity exceeds the standard (>70%).
3、 Comprehensive management measures
1. Personnel and Process Management
Training and Assessment:
Construction personnel need to undergo moisture-proof and ventilation operation training to master skills such as using dehumidification equipment, humidity monitoring, and emergency response.
Construction log record:
Detailed records of environmental temperature and humidity, ventilation parameters, coating batches, and other information for each batch of construction, facilitating quality traceability.
2. Emergency plan development
Response to sudden high humidity:
Prepare portable dehumidifiers, industrial fans and other emergency equipment, and immediately activate them when the main dehumidification system fails.
Coating defect repair:
For defects such as blistering and whitening caused by moisture, a local polishing and re coating process is used, and the substrate needs to be thoroughly dried before re coating.