How to monitor the melt pump when it is running

When the melt pump is running, it needs monitoring data to determine whether the equipment is operating normally, so what data need to be monitored?

1. The flow of the machine head changes with the change of outlet pressure, and the outlet pressure must be constant. Generally speaking, the fluctuation of outlet pressure shall not exceed ±10psi (1psi=0.00689Mpa). Large fluctuations are usually transmission problems, requiring motor technicians to adjust transmission parameters. This problem can also occur if the melt pump is severely worn.

chemical gear melt pump

2. The change in suction pressure reflects the change in the output of the extruder. The main function of the melt pump is to eliminate these changes, but the range of changes that can be controlled is limited. Even if the melt pump can continuously keep the output of the polymer constant, the melt temperature will change. Keep the suction pressure stable, the screw speed changes, and the melt temperature changes. The change of melt temperature directly causes the melt flow of the die and the change of product size.

3. The fluctuation range of the ideal suction pressure shall not exceed ±100psi. ±50psi. If the change exceeds this value, the flow rate of the machine head will change. Therefore, it is necessary to reduce the sensitivity of the extruder motor to pressure fluctuations. This usually increases the bandwidth of the proportional control and detection pressure to make the extruder motor have this characteristic. If this method cannot control the fluctuation in a small range, it is likely to be a problem of the extruder itself, so it must be analyzed separately.

The power required for the rotation of the gears of the melt pump must be constant. Even if some ampere current changes occur during driving, it also means that there is a problem. This may be a simple parameter setting problem, or it may be a mechanical problem in the pump body, gearbox or drive shaft, or excessive suction pressure fluctuations.

Any questions about our products, please feel free to contact us! We promise you high-end products and first-class service.Look forward to our cooperation!!!