|
Common Faults |
Possible Causes |
Troubleshooting Methods |
| Abnormal Noise and Vibration |
1.Inside the gearbox: Bearing/gear wear and poor lubrication. 2.At the cylinder: Screw bending and scraping against the cylinder, as well as material friction caused by excessively low temperature settings. 3.Vibration of the whole machine: Hard foreign objects mixed in the materials. |
1.Inspect and replace damaged bearings or gears, and ensure adequate lubrication. 2.Straighten or replace the screw; appropriately increase the set temperature. 3.Shut down the machine for cleaning and check the cleanliness of the materials. |
|
Cylinder Water Leakage |
The welding points of the cylinder cooling runner are perforated due to sand holes, air bubbles, or long-term corrosion. |
Shut down the machine immediately, replace or weld the cylinder for repair, and conduct a flaw detection test. In case of emergency, temporary production can be maintained by means of compressed air cooling or similar methods. |
|
Vacuum Port Material Regurgitation |
High water content in the raw materials leads to vaporization and generation of a large amount of water vapor in the vacuum section. If the pumping capacity of the vacuum pump is insufficient, the molten materials will be carried over and cause pipeline blockage. |
Fully pre-dry the raw materials. Calculate and replace the vacuum pump with sufficient pumping capacity. Optimize the structure of the vacuum port. |
|
Product with Discolored Pellets/Impurities |
1.Vacuum waste liquid flows back into the cylinder due to condensation or overflow of the collection tank. 2.Processing acidic materials causes corrosion of the screw or cylinder, and the peeled metal chips are mixed into the materials. |
1.Maintain an appropriate vacuum level, insulate the vacuum pipeline to prevent condensation. 2.Replace the screw/cylinder with corrosion-resistant nickel-based alloy materials and increase the frequency of maintenance inspections. |
|
Extrusion Instability |
1.Screw Seizure or Ring-shaped Material Blockage: The main cause is the interruption or insufficient flow of cooling water, which leads to premature melting and adhesion of materials to the screw at the feed inlet. 2.Uneven Mixing: It may cause pitting defects on downstream injection-molded products. |
1.Inspect and ensure that the cooling water system is functioning properly, and adjust the water pressure and flow rate to the specified values. 2.In terms of operation, try reducing the temperature of the feeding section and increasing the screw speed; in terms of equipment, adjust the screw configuration and add mixing sections. |
Basic Logic of Troubleshooting
When a fault occurs, it is recommended to follow the principle of "First check the process, then the raw materials, and finally the equipment" for troubleshooting:
1.Check Process Parameters: First, verify that the settings of temperature in each section (especially the feeding section), screw speed, vacuum level and other parameters are accurate and stable.
2.Check Raw Materials: Confirm whether the raw materials are fully dried, free of impurities, and whether there is any change in the formula or batch.
3.Check Equipment Components: After ruling out the above two factors, focus on inspecting the equipment hardware mentioned in the table above.