How to troubleshoot the feeding system

The first step in troubleshooting is to verify the condition of the raw materials themselves. Moisture-induced clumping, uneven particle sizes, or the presence of impurities can increase feeding resistance, leading to material bridging or blockages. Additionally, significant variations in the melt index between material batches can cause fluctuations in plasticization, thereby affecting feeding stability. Therefore, it is crucial to verify that the raw materials have undergone adequate drying, screening, and homogenization to ensure their physical properties meet the extrusion process requirements.

Impeded feeding is often closely linked to the condition of mechanical components. Check the hopper's cooling water circuit for obstructions; inadequate cooling can cause raw materials to melt and clump prematurely at the feed inlet, adhering to the screw and causing slippage. Simultaneously, inspect the drive belt connecting the feeder motor and the screw for looseness or slippage, and check the gearbox gears for wear. For equipment that has been in long-term operation, pay attention to the clearance between the screw and the barrel; excessive clearance significantly reduces conveying efficiency, leading to a sudden drop in extrusion output.

Fluctuations in feed rate often stem from instability in the electrical system. Focus on checking whether the feeder motor speed is consistent and if the control system is experiencing signal interference. If the displayed feed rate fluctuates erratically, the sensor may be affected by mechanical vibration or static electricity; check if flexible connections have hardened and ensure shielded cables are independently grounded. Furthermore, poor lubrication of the main motor bearings or damage to the thyristor rectifier circuit can cause unstable current, indirectly preventing the feeding system from maintaining a constant feed rate.

For central feeding systems utilizing vacuum suction, inspecting the piping and power source is critical. A lack of suction or an interruption in material supply is usually caused by pipeline blockages, air leaks in the shut-off valves, or excessive dust accumulation on the dust collector filter element. Check that the vacuum pump oil level is normal and that seals are undamaged; use soapy water to detect any air leaks in the piping. If necessary, switch to the pipeline purge mode or disassemble the blocked sections for cleaning to restore normal negative pressure in the feeding system.