Hot runner systems are key components of high-efficiency, high-precision injection molds, widely used in mass production of plastic products. They improve production efficiency, reduce material waste, and ensure product consistency. However, hot runner systems have complex structures (nozzles, manifolds, heaters, thermocouples) and high operating temperatures, requiring standardized maintenance to avoid failures like clogging, leakage, and temperature inaccuracy.
Daily Inspection and MonitoringDaily inspection focuses on temperature stability and system tightness. Monitor heater and thermocouple operation in real time to ensure temperature fluctuation ≤ ±3°C. Check for glue leakage at nozzle gates and manifold connections—immediately stop production to clean and repair if leakage occurs. Inspect air/hydraulic pipelines for blockage or leakage to ensure stable needle valve operation. Clean gate residues regularly to prevent carbonization and clogging.
Heater and Thermocouple MaintenanceHeaters and thermocouples are vulnerable parts of hot runner systems. Regularly check for heater damage, aging, or loose connections—replace damaged heaters promptly. Ensure thermocouples are properly installed and in close contact with the nozzle/manifold to avoid temperature measurement inaccuracy. Calibrate thermocouples quarterly to ensure temperature control precision, which is critical for preventing material degradation and product defects.
Manifold MaintenanceManifolds distribute melt evenly to each nozzle, requiring regular cleaning and inspection. After long-term use, remove the manifold to clean internal flow channels with special cleaning agents and copper brushes, removing carbon deposits and residual glue. Check for manifold deformation or cracks (caused by uneven heating); repair or replace if necessary. Reinstall the manifold with even torque to ensure sealing and avoid glue leakage.
Safety and Shutdown MaintenanceStrictly follow safety procedures during maintenance: cut off power and cool down the system before disassembly to avoid burns. Use insulating tools when handling electrical components (heaters, thermocouples) to prevent electric shock. For long-term shutdowns, clean the entire hot runner system, blow dry with compressed air, and apply anti-rust oil to metal parts. Protect electrical interfaces from dust and moisture to prevent short circuits.
Common Failure TroubleshootingHot runner system failures are mostly related to temperature and cleanliness. Clogging is caused by carbonization or residue—clean the system thoroughly and check temperature parameters. Glue leakage results from poor sealing or worn parts—replace seals or damaged nozzles/manifolds. Temperature inaccuracy is caused by faulty heaters or thermocouples—calibrate or replace them promptly.
ConclusionHot runner system maintenance is key to ensuring stable injection molding production. Daily inspection, regular cleaning, and timely replacement of vulnerable parts extend system service life, reduce downtime, and improve product quality. Establishing a standardized maintenance schedule and training operators to master basic maintenance skills are essential for maximizing the performance of hot runner systems.
