Quarterly Maintenance
Perform quarterly maintenance after every 500–600 hours of operation. Estimated time: 2–4 hours.
Hydraulic System
| Task | Details |
|---|---|
| Full oil change | Drain entire hydraulic oil charge. Clean tank interior with lint-free cloth. Replace all filter elements. Refill with approved grade (typically ISO VG 46 or VG 68). |
| Flush if necessary | If oil analysis shows high particle count or varnish, perform a full system flush before refilling. |
| Suction filter element | Replace (if model has a serviceable suction filter). |
| Hydraulic cylinder seal check | Extend and retract all cylinders (clamp, injection, ejector, carriage) at full stroke. Look for external leakage at rod seals. |
| Valve bank torque | Check mounting bolt torque on all proportional and directional valves. |
| Accumulator bladder | Replace bladder or diaphragm every 2 years or per OEM spec. |
Electrical System
| Task | Details |
|---|---|
| Full cabinet cleaning | Use vacuum with HEPA filter and low-pressure dry air. Do NOT use compressed air that blows dust into drives. |
| Relay and contactor check | Inspect contacts for pitting or welding. Replace if worn. |
| Cable integrity check | Inspect all flexible cables in drag chains. Replace cables with cracked jackets or exposed conductors. |
| Motor insulation test | Perform megger test (500V) on main pump motor and screw drive motor. Minimum 5MΩ. |
Mechanical System
| Task | Details |
|---|---|
| Full tie bar nut re-torque | Re-torque all four tie bar nuts to specification. Re-check elongation. |
| Platen parallelism | Measure platen parallelism with dial indicators. Deviation should be ≤ 0.05 mm/m. |
| Injection unit alignment | Check barrel alignment relative to the clamp centerline. |
| Screw / barrel wear check | Measure screw tip and barrel inner diameter wear. Replace if clearance exceeds 0.4 mm for general-purpose screws. |
| Anti-rotation device (screw drive) | Inspect screw anti-rotation mechanism for wear. |
Process Verification
| Task | Details |
|---|---|
| Temperature sensor calibration | Compare HMI temperature reading to a calibrated external meter at 3 points (100°C, 200°C, 300°C). |
| Pressure transducer calibration | Check injection and clamp pressure readings against a calibrated gauge. |
| Position feedback calibration | Verify screw position, clamp position, and ejector position feedback against physical measurements. |
| Shot weight repeatability | Run 20 consecutive cycles. Measure shot weight. Cpk should be ≥ 1.33. |