Tests for Dimensional and Structural Verification Full-stroke "Go" Gauge Test: A standard nylon "Go" gauge that is matched to the nominal inner diameter of the bore should be slowly inserted coaxially all the way to the bottom. Verify that the repaired bore shape satisfies the original design criteria, that the bore diameter tolerance and coaxiality deviation are ≤0.05mm, and that the stroke moves smoothly without snagging or binding.
Endoscopic Examination: Scan the whole bore's inner wall using a small-diameter industrial endoscope. Verify that there are no lingering burrs, scratches, or chips; make sure the restored surface is level and smooth, free of any leftover metal fragments or grinding dust.
Verification Tests for Electrical Safety Insulation Resistance Retest: The armoured sheath should be fully inserted into the bore. Measure the insulation resistance between the housing and the thermocouple poles (within the sheath) using an insulation tester (megohmmeter). Passing is defined as a measurement of ≥100MΩ at room temperature, which removes the possibility of leakage from leftover metal particles.
Wiring Continuity Test: Verify the thermocouple circuit's correct continuity using a multimeter to make sure there are no loose connections or open circuits. Make that the shielding layer is consistently grounded at one end and that the compensating wire calibration grade corresponds with the thermocouple.
Verification Tests for Temperature Control Performance Constant Temperature Accuracy Comparison Test: The hot runner should be heated to the standard working temperature and kept there for half an hour. A variation of ≤±1℃ between the controller display and the actual temperature is deemed acceptable when compared to a calibrated standard contact thermometer.
Calibration Test for Temperature Control Accuracy: Update compensation settings, start PID auto-tuning, and perform single-point calibration on the Husky temperature controller. Verify that there is no drift brought on by mismatched parameters and that the temperature control system reacts appropriately.
Verification Tests for Operational Stability Heating/Cooling Cycle Test: Conduct three successive cycles of heating and cooling between the maximum working temperature and room temperature. Throughout the procedure, keep an eye on the temperature curve to make sure there are no random spikes or unidirectional continuous drift, and that temperature variations stay within ±0.5°C. Temperature Uniformity Test: The actual temperatures in each zone of the hot runner system are concurrently monitored using a multi-channel thermocouple data collecting module. The uniformity and stability of the total thermal field are confirmed by the control of temperature fluctuations inside the multi-cavity runner to within 2%.
Production can formally restart if all test requirements are satisfied, hence removing any potential quality hazards related to the first starting period.
