These are categorized into six main types: hydraulic system, injection system, mold clamping system, temperature control system, motor and screw, and alarm/abnormality.

 

1. Weak Injection, Incomplete Injection (Insufficient Injection)
Causes: Insufficient injection pressure/flow; low material temperature; nozzle blockage; poor barrel feeding; worn check valve leading to leakage.
Solutions: Appropriately increase injection pressure and speed; increase barrel and nozzle temperature; disassemble and clean nozzle; check for bridging at discharge port; replace or repair injection check valve.
2. Slow Injection Action
Causes: Insufficient oil pressure; clogged proportional valve; internal leakage in hydraulic cylinder; abnormal oil viscosity.
Solutions: Check system pressure; clean proportional valve; repair injection cylinder; replace with qualified hydraulic oil.
3. Screw not feeding, slipping
Causes: Material temperature too high, slipping; barrel temperature too low; screw wear; coking or jamming at feed inlet; excessive back pressure.
Solutions: Lower barrel temperature; raise feed section temperature; inspect screw and barrel; clean feed inlet; reduce back pressure.
4. Nozzle drooling, leaking
Causes: Nozzle temperature too high; nozzle orifice too large; excessive back pressure; prolonged pressure holding during shutdown.
Solutions: Lower nozzle temperature; install self-locking nozzle; reduce back pressure; remove glue before shutdown.
5. Screw abnormal noise, vibration
Causes: Metal impurities in material; wear between screw and barrel; excessively low temperature leading to high resistance; damaged bearing.
Solutions: Immediately stop machine, clean impurities; inspect screw and barrel; adjust heating temperature; replace thrust bearing.

6. Mold Locking Failure Reported
Causes: Foreign objects in mold; incorrect mold thickness adjustment; dry crank arm; low mold locking pressure and speed; abnormal safety door limit switch.
Solutions: Clean parting surface; readjust mold thickness; add grease to crank arm; appropriately increase mold locking pressure; check safety door switch.
7. Mold Opening Failure or Jamming
Causes: Insufficient mold opening pressure and speed; mold seizing; uneven force on tie rod; damaged cylinder seal.
Solutions: Increase mold opening parameters; check for mold sticking; adjust four tie rods; repair mold opening cylinder.
8. Abnormal Mold Locking Noise or Loud Impact Sound
Causes: Lack of lubrication in crank arm; improper fast/slow switching position; buffer failure; excessively tight mold adjustment.
Solutions: Fully lubricate machine hinge; optimize mold locking deceleration position; repair buffer cylinder; fine-tune mold thickness.
9. Mold Adjustment Unable to Move
Causes: Mold adjustment motor overload; mold adjustment nut stuck; limit switch triggered; insufficient oil pressure.
Solutions: Power off and manually rotate mold adjustment mechanism; clean and lubricate threads; reset limit switch; repair hydraulic circuit.

10. Overall Machine Pressure Not Reaching Maximum
Causes: Oil pump wear and internal leakage; overflow valve, pressure valve blockage, valve core stuck; deteriorated hydraulic oil; insufficient oil level in tank.
Solutions: Clean overflow valve; repair or replace oil pump; replace hydraulic oil; replenish oil level.
11. Oil Temperature Too High
Causes: Cooler blockage; insufficient cooling water flow; long-term pressure overflow; oil pump wear and overheating.
Solutions: Clean cooler; increase cooling water flow; optimize process to reduce high-pressure overflow; repair oil pump.
12. Hydraulic Oil Foaming and Vibration
Causes: Air leakage in suction line; low oil level; air introduced into return oil above fluid surface.
Solutions: Tighten suction connector; add oil; adjust return line position.
13. Oil cylinder leakage
Causes: Aging seals; cylinder scoring; loose connections.
Solutions: Replace oil seal; repair cylinder; tighten pipe connections.

14. Temperature fails to rise in a certain section
Causes: Burnt-out heating coil; loose power cord; damaged thermocouple; faulty temperature control board.
Solutions: Use a multimeter to check continuity of heating coil; tighten wiring; replace thermocouple; repair temperature control module.
15. Temperature out of control, continuously rising and exceeding temperature limit
Causes: Solid-state relay stuck; malfunctioning temperature controller.
Solutions: Immediately disconnect power and cool down; replace SSR solid-state relay; repair temperature control board.
16. Temperature fluctuates wildly, sometimes high, sometimes low
Causes: Loose thermocouple, poor contact; partially broken heating coil; oxidized wiring.
Solutions: Tighten thermocouple; replace damaged heating coil; polish wiring terminals.

17. No response from any machine operation
Causes: Emergency stop button pressed; safety door not closed properly; main power supply or contactor malfunction; servo alarm.
Solution: Reset emergency stop; close safety door properly; check main circuit; check servo driver code.
18. Inconsistent movement, sometimes fast, sometimes slow
Causes: Hydraulic oil contains impurities; proportional valve stuck; oil aging; servo signal interference.
Solution: Change oil; filter hydraulic system; clean proportional valve; shield signal cable.
19. Motor cannot start
Causes: Overload protection; phase loss; contactor damage; servo fault alarm.
Solution: Investigate motor overload; check three-phase power supply; replace contactor; repair according to servo alarm code.
20. Automatic mode does not cycle, stuck at a certain step
Causes: Position sensor malfunction; time parameter set to 0; interlock condition not met; mold signal abnormality.
Solution: Check electronic ruler and proximity switch; verify time intervals; investigate mold limit signal.

21. Slow Material Storage
Causes: Excessive back pressure; low material temperature; worn screw; insufficient oil pump displacement.
Solutions: Reduce back pressure; appropriately increase temperature; repair screw; check oil pump.
22. Back Pressure Cannot Be Adjusted, No Back Pressure
Causes: Sticking back pressure valve; blocked oil circuit; locked parameters.
Solutions: Disassemble and clean back pressure valve; clear oil circuit; unlock parameters.
23. Inability to Extract Glue
Causes: Insufficient extraction pressure and speed; nozzle blocked by cold material; cylinder malfunction.
Solutions: Increase extraction parameters; increase nozzle temperature; repair injection cylinder.

 

24. Machine Leakage (Cooling Pipeline)
Causes: Aging joints; cracked water pipes; damaged mold water nozzles.
Solutions: Replace water pipe joints; repair water nozzles; check sealing rings. 25. Robot arm or signal docking abnormality
Causes: Loose communication plug; burnt I/O point; incorrect parameter matching.
Solution: Tighten communication cable; replace input/output module; verify docking parameters.
26. Unable to inject glue after restarting following shutdown
Causes: Cold material clogging nozzle; partial carbonization of barrel; stuck check valve.
Solution: Clean by air injection after heating; disassemble and clean nozzle; repair check ring.
27. Excessive machine vibration
Causes: Uneven foundation; loose oil pump mounting; excessive pressure shock.
Solution: Level foundation; tighten oil pump; add motion deceleration buffer.
28. Oil level alarm
Causes: Hydraulic oil loss or leakage; dirty oil level sensor.
Solution: Check for leaks and add oil; clean oil level sensor.
29. Lubrication alarm
Causes: Insufficient grease; lubrication pump malfunction; blocked oil line.
Solution: Add grease; repair lubrication pump; clear oil lines.
30. Electronic ruler position drift, unstable dimensions
Causes: Loose or worn electronic ruler; interference with signal lines; unstable power supply.
Solutions: Tighten electronic ruler; replace sensor; shield circuit; ensure stable power supply.