Key Points For Inspection Before Hot Melt Glue Production Line Goes Into Production | JCT Machinery

Preliminary inspection after installation (static inspection)

1. Equipment Appearance and Connections

• All equipment (sigma mixer, reactor, extruder, transfer pump, molding system, cooling system, etc.) must be free of damage, deformation or rust.
• All flanges, bolts and seals must be securely installed and tightened.
• Pipelines must be properly connected, with clear flow direction markings (especially for thermal oil, cooling water and vacuum lines).
• Cables must be neatly routed, protective conduits must be intact, and no exposed wires or damaged casings should be present.

2. Safety Devices and Protective Measures

• The safety valve, pressure gauge, and thermometer are all installed and readings are normal.
• The emergency stop switch is functioning properly and clearly located.
• External protective covers for all rotating components (such as the extruder screw and agitator shaft) are fully installed.
• The grounding wire and insulation resistance test have passed (≥1MΩ).

Electrical and Control System Inspection

1. Control System

• Before powering on the electrical control cabinet, inspect the interior for loose components or debris.
• Check that communication between the PLC, inverter, temperature control module and touch screen is normal.
• In manual operation mode, confirm that the rotation direction of each motor is correct (especially the agitator motor and extruder screw motor).
• Ensure that the temperature controller, pressure sensor, level gauge, and other sensors are accurately collecting signals.

2. Protection and Alarm System

• Simulate overtemperature, overvoltage, phase loss, and overload to verify that the alarm is triggered.
  
• Check the overtemperature power-off protection of the thermal oil heating system.
  
• Confirm that the vacuum system's backflow prevention device and vacuum valve are functioning and reliable.

Mechanical and Transmission Inspection

1. Agitation and Transmission

• Manually rotate the agitator shaft or screw to ensure there is no binding or unusual noise.
  
• Check the lubricating oil level in the bearings and reducer to ensure it meets the specified level.
• Check seals (such as mechanical seals and packing seals) for leaks.
  

2. Transmission Coupling

• Alignment accuracy meets requirements (coaxiality deviation ≤ 0.1mm).
  
• Fix the screws with lock washers and tighten securely.
  

No-load Test Run Sequence

1. Start the thermal oil circulation heating system and test the heating rate and temperature control accuracy.
   
2. Start the motors of each device and run them for 5–10 minutes.
   
3. Check for vibration, abnormal noise, and overheating.
   
4. Check the coordination of the temperature control, mixing, vacuum, discharging, and pelletizing systems.

No-load Operation Requirements

• Temperature fluctuation at each control point ≤ ±2℃.
• Stable stirring speed, no noticeable noise.
• No oil, water, or air leakage.
  
• Current within rated range.

Preparations For A Trial Run With Material

After heating to the set temperature according to process requirements:

• Check the temperature difference between each heating zone.
• Simulate the feeding process (a small amount of raw material or simulated material).
• Confirm that the material discharge is smooth, the temperature control is stable, and there are no signs of material stagnation or burning.
  

Final Confirmation Before Official Material Loading

1. All safety devices have passed testing.
2. No-load operating current, temperature, and vacuum baseline data have been recorded.
3. All systems' cooling cycles are normal.
4. Operator training has been completed, clarifying job responsibilities and operating procedures.