Electrical System Safety
Always turn off the main power supply before performing any electrical maintenance tasks. Never work on live circuits unless absolutely necessary for diagnostic purposes, and only qualified electricians should perform such work. Prevent water ingress into the control cabinet during mold changes and machine cleaning. Monitor the control cabinet internal temperature closely to prevent electronic component damage from overheating.
Wire Connector and Motor Inspection
Check all wire connectors regularly for tightness and signs of damage. Loose or damaged connectors cause intermittent signal transmission failures that lead to production defects and machine stoppage. Clean the main drive motor annually to avoid dust accumulation that causes heating problems and insulation degradation. Ensure proper overload protection settings are configured and tested.
Heating System Care
Check and tighten all heating tubes regularly to ensure effective heat transfer to the barrel. Loose heater bands create hot spots and uneven heating. Inspect thermocouples for accuracy and secure mounting. Replace old or damaged heater bands promptly. If plastic material sticks to heater bands, clean it off immediately to prevent burning and insulation damage.
Electromagnetic Contactor Maintenance
Check electromagnetic contactors in both AC and DC electrical boxes regularly for proper functioning. Look for signs of overheating such as discolored terminals or a burning smell. Replace any contactor showing damage or inconsistent operation. Clean contact surfaces to remove dust, oil, and oxidation.
Mechanical System: Platen Parallelism
Ensure the movable and fixed platens remain parallel at all times. Check parallelism regularly using dial indicators. Uneven mold closing causes product flash, dimensional inaccuracies, and accelerated mold and machine wear. Adjust tie bar nuts as needed according to manufacturer specifications to maintain proper alignment.
Mold Thickness and Lubrication
Check and adjust mold thickness settings regularly to ensure smooth, long-term production without over-stressing the clamping mechanism. Keep all mechanical moving parts properly lubricated through the automatic lubrication system. Verify the lubrication pump operates at the correct interval, typically every 30 minutes for toggle joints, moving platen, and cross platen.
Injection Unit Maintenance Tips
When cleaning the material hopper, ensure all injection molding material is completely cleared out. Before charging new material, limit screw speed to 40 rpm and feed slowly. After material melts and flows through the nozzle, increase to normal operating speed to prevent check ring friction or blockage. Use PP and PE plastics for purging PVC, POM, and other easily decomposed plastics. When removing the nozzle and screw tip, never heat above 400 degrees Celsius to prevent strength reduction and breakage.
Bearing Inspection
Regularly check all bearings for abnormal sounds, vibration, or temperature increases. Listen for grinding or squealing noises during operation. Use an infrared thermometer to check bearing housing temperatures. Replace any bearing showing signs of wear, roughness, or excessive clearance. Proper bearing maintenance prevents catastrophic mechanical failures and unplanned downtime.
