PE modified three-screw granulators play a crucial role in the production of polyethylene and its modified materials, handling key processes such as melting, mixing, dispersion, and pelletizing.Their stable operation directly impacts product quality and production efficiency. Due to the complex structure of this equipment, involving multiple stages such as high-temperature melting, coordinated shearing by three screws, and water-ring or air-cooled pelletizing, scientific and standardized maintenance is particularly important. This can effectively prevent malfunctions, extend the lifespan of key components, and maintain process consistency.
Daily maintenance should be carried out at the end of each shift or daily production. Before operation, check the barrel inlet, die head, and screw surface for any residual modified material and clean it promptly to prevent solidification, which could increase starting resistance or cause localized overheating. Confirm that the temperature control instruments in each heating zone are functioning normally and that the wiring terminals are free of looseness or oxidation. Check that the water circulation or cooling system pipelines are unobstructed and the filters are clean to avoid PE melt adhesion or pellet deformation due to insufficient cooling. The lubrication system requires checking the oil level and quality, and replenishing or replacing the lubricating oil according to the calibrated schedule. Special attention should be paid to the lubrication condition of the gearbox and bearing housings to prevent abnormal temperature rise due to dry friction.
Weekly maintenance should focus on re-inspecting the transmission and fasteners. Check the operating noise and vibration of the main motor and reducer, and confirm that the coupling or belt tension meets technical requirements. Verify the torque of the external fastening bolts of the screw and barrel to prevent loosening due to vibration and affecting coaxiality. Inspect the sharpness and installation firmness of the blades of the water ring pelletizer, and promptly sharpen or replace dulled blades to maintain uniform pellet shape. The working condition of the heating coils and thermocouples should also be included in the weekly inspection to ensure sensitive temperature control response and no excessive local temperature differences.
Monthly maintenance is recommended to be performed by professional technicians for systematic testing. This includes measuring the clearance between the screw and barrel, assessing the℃of wear and determining whether repair or replacement is needed; calibrating the temperature and pressure sensors to ensure accurate data acquisition; disassembling and inspecting the water pump impeller and seals, and removing impurities and scale from the circulating water system to maintain good heat exchange efficiency. For equipment operating under high loads for extended periods, the internal gear meshing surfaces of the reducer should be inspected for pitting or galling. If necessary, the oil should be replaced or a major overhaul performed.
Annual maintenance encompasses a comprehensive overhaul, requiring the disassembly of key components for flaw detection and dimensional verification; replacement of aging seals, bearings, and electrical components; recalibration of the screw and barrel coaxiality and equipment levelness to prevent accelerated wear due to installation deviations; and dust removal and functional testing of the electrical control system to ensure reliable operation of contactors, relays, and safety interlock devices. For inorganic filler or additive residues commonly involved in PE modification, the barrel and screw surfaces should be thoroughly cleaned to prevent scratches or corrosion from hard particles.
Maintenance work should be integrated with operating records to establish a closed-loop management system for inspection, maintenance, and troubleshooting, with cycles flexibly adjusted based on actual output, material characteristics, and operating conditions. Through rigorous daily maintenance and periodic overhauls, the PE modification three-screw granulator can consistently maintain excellent mixing and plasticizing performance, reducing the risk of unplanned downtime and providing a solid guarantee for high-quality, high-efficiency modified production.