(1) Routine maintenance is a regular, ongoing task that does not occupy operating time and is usually completed during machine start-up. The focus is on cleaning the machine, lubricating moving parts, tightening easily loosened threaded parts, and timely inspection and adjustment of the motor, control instruments, working components, and pipelines.
(2) Periodic maintenance is generally performed after the extruder has run continuously for 2500-5000 hours and then stopped. This requires disassembly for inspection, measurement, and assessment of the wear condition of major components, replacement of parts that have reached their wear limits, and repair of damaged parts.
(3) Running the machine empty is prohibited to prevent the screw and barrel from becoming rough.
(4) If any abnormal noise occurs during extruder operation, stop the machine immediately for inspection or repair.
(5) Prevent metal or other foreign objects from falling into the hopper to avoid damaging the screw and barrel. To prevent ferrous debris from entering the barrel, a magnetic attractor or magnetic frame can be installed at the material inlet. Material must be pre-screened to prevent debris from falling in.
(6) Maintain a clean production environment. Prevent waste and impurities from clogging the filter plates, affecting product output and quality, and increasing die head resistance.
(7) When the extruder needs to be shut down for an extended period, apply anti-rust grease to the working surfaces of the screw, barrel, and die head. Small screws should be suspended in the air or placed in a dedicated wooden box, leveled with wooden blocks to prevent deformation or damage.
(8) Regularly calibrate the temperature control instrument, checking its accuracy and sensitivity.
(9) The maintenance of the extruder's gearbox is the same as for a standard gearbox. Primarily check for wear and failure in gears, bearings, etc. Use the lubricating oil specified in the machine's instruction manual, adding oil to the specified level. Insufficient oil leads to inadequate lubrication and reduced component lifespan; excessive oil causes excessive heat generation, higher energy consumption, and oil deterioration, also resulting in lubrication failure and damage to components. Replace leaking gaskets in the gearbox promptly to ensure adequate lubrication.
(10) The cooling water pipes attached to the extruder are prone to scale buildup on the inner wall and corrosion/rust on the outer surface. Careful inspection is necessary during maintenance. Excessive scale can clog the pipes, preventing effective cooling, and severe corrosion can cause leaks. Therefore, descaling, corrosion prevention, and cooling measures must be taken during maintenance.
(11) For the DC motor driving the screw, special attention should be paid to brush wear and contact condition. The insulation resistance of the motor should also be measured frequently to ensure it is above the specified value. Furthermore, the connecting wires and other components should be checked for rust, and protective measures should be taken accordingly.
