Ensuring the sealing after magnesium oxide refilling hinges on employing a highly reliable sealing process, strictly controlling environmental cleanliness, and achieving an IP65 or higher protection rating. The specific implementation methods are as follows:
1. Select a High-Reliability Sealing Process
|
Sealing Method |
Applicable Scenarios |
Key Requirements |
|
Ceramic Sealing Adhesive |
High-temperature, high-humidity conditions (e.g., medical, injection molding) |
Uses ceramic-based adhesive with a temperature resistance of ≥600℃, forming a dense insulating layer after curing. |
|
Metal Sealing (e.g., brazing) |
Extreme environments or long-term operating equipment |
Uses argon arc welding or induction welding to ensure the weld is free of pores and cracks. |
|
Composite Sealing Structure |
Scenarios with high reliability requirements |
Double protection with ceramic adhesive and a metal sealing ring, improving long-term stability. |
After sealing, an IP65 or higher protection rating must be achieved to prevent dust and moisture intrusion.
2. Strict Control of Operating Environment
Cleanroom Class: Sealing operations are performed in a cleanroom of ≤100,000 class to avoid dust contamination leading to sealing defects;
Humidity Control: Relative humidity ≤30% to prevent magnesium oxide powder from absorbing moisture before sealing;
Inert Atmosphere Protection: High-purity nitrogen (oxygen content <100ppm) is introduced during the sealing process to prevent high-temperature oxidation.
For every 10% increase in humidity, the sealant's curing strength decreases by approximately 8%, significantly impacting long-term reliability.
3. Sealing Quality Inspection and Verification
Visual Inspection: The sealing adhesive is free of bubbles, cracks, and shrinkage cavities; metal welds are uniform and continuous;
Air Tightness Test: The finished product is subjected to 0.3MPa pressure and held for 30 minutes without leakage;
Moisture Test Verification: After being placed in an environment of 40℃ and 95% RH for 48 hours, the insulation resistance is ≥200 MΩ;
X-ray Inspection: Check the sealing area for micropores, misalignment, or insufficient filling.
In practice, X-rays can detect micron-level gaps invisible to the naked eye, making it a mandatory inspection item for high-end applications.
4. Selecting Compliant Service Providers and Standard Materials Prioritize entrusting sealing treatment to units that participated in the formulation of the HG/T 6445-2025 standard, such as:
Liaoning Jiashun Technology; Dashiqiao Meier Magnesium Products; Shanghai Shiye Zhentai Chemical. Original manufacturer-certified sealing materials must be used, and sealing process parameter records and test reports must be obtained to ensure traceability.
