Determining if a hot runner connector is damaged requires a comprehensive assessment of three aspects: visual damage, abnormal electrical performance, and functional failure. This is especially important in Xiaogan's current rainy season with high humidity, where hidden damage caused by corrosion, oxidation, or mechanical stress should be carefully monitored.
1. Visual Inspection (Directly Identifying Physical Damage)
Contact Condition: Observe using a magnifying glass or endoscope. Severe discoloration (dark brown, black), powdery deposits, pitting, or delamination indicate deep corrosion or oxidation.
Housing and Structure: Check the metal housing for deformation, cracks, or rust. Check plastic parts for embrittlement, cracking, or signs of melting.
Seals: Confirm that the O-rings are not aged, broken, or have lost elasticity to prevent moisture intrusion and internal damage.
Pin/Socket: Observe for bending, pin retraction, enlarged holes, or plating peeling, which affect insertion and removal reliability.
Key areas: Frequently plugged-in/unplugged intermediate pins, exposed terminal edges, and sealed contact surfaces.
2. Electrical Performance Testing (Quantitative Verification)
Contact Resistance Test: Measured using a four-wire micro-ohmmeter. A resistance value > 50mΩ or significant fluctuations indicate deterioration of the internal conductive path.
Insulation Resistance Decrease: Applying 500VDC to the thermocouple circuit, an insulation resistance < 10MΩ suggests a risk of leakage or short circuit.
Soldering Refusal: During repair, the solder fails to spread and shrinks into a ball shape, indicating severe oxidation or contamination of the metal surface.
3. Functional Performance (Operational Anomaly Judgment)
Intermittent Circuit Breaker: Temperature fluctuations, sudden power outages in the heating circuit, and signal interruption alarms occur during equipment operation.
Abnormal Temperature Rise: Localized overheating of connectors during power-on testing (hot spot temperature difference >10℃), with obvious hot spots displayed in thermal imaging.
Abnormal Insertion/Removal: Excessive insertion force, jamming, or excessive looseness; failure of the locking mechanism, leading to loosening during operation.
Note: If high resistance, functional instability, and appearance deterioration occur simultaneously, it can be determined as functional damage and replacement is necessary.
4. Environmental and Usage Factors for Auxiliary Judgment
Long-term exposure to high temperature and humidity environments (such as the rainy season in Xiaogan) without moisture-proof measures;
Frequent insertion/removal or vibration conditions leading to plating wear and structural fatigue;
Improper cleaning (such as pickling or polishing) causing secondary damage.
