Method for improving dimensional accuracy of glass fiber reinforced polypropylene FRPP pipe

Summary:Generally, there is a large fluctuation in the outlet pressure of the FRPP pipe extruder, which will affect the dimensio...
Generally, there is a large fluctuation in the outlet pressure of the FRPP pipe extruder, which will affect the dimensional accuracy of the FRPP pipe. If we install a melt pump between the outlet of the extruder and the die, it can be used to stabilize the extrusion. The pressure fluctuation at the outlet of the machine makes linear extrusion possible, thereby improving the dimensional accuracy of the FRPP pipe and increasing the output of the extruder per unit time. The melt pump is a kind of positive displacement conveying equipment. The high-precision gear gap and volumetric structure design make stable and balanced extrusion possible. It is widely used in FRPP pipe production lines and has achieved good results:
Stable extrusion, improve dimensional accuracy of extruded products, and reduce scrap rate. In the extrusion process, it is unavoidable that the material feeding amount is not uniform, the temperature of the barrel and the head fluctuates, and the pulsation of the screw speed is unavoidable. The use of the melt gear pump can eliminate the feeding error of the feeding system, greatly reduce the fluctuation of the upstream process transmission, quickly enter a stable working state, improve the dimensional accuracy of the FRPP pipe, and reduce the scrap rate.
Reduce energy consumption, achieve low temperature extrusion, and extend the life of the machine. Since the extruder is equipped with a polymer melt pump, the decompression function of the FRPP pipe extruder is transferred to the gear pump to complete, the extruder can work at low pressure and low temperature, the leakage flow is greatly reduced, and the output is increased. The gear pump can establish the head pressure more easily and effectively than the extruder, and can reduce the back pressure of the extruder, so that the axial force on the screw is reduced and the service life is prolonged.
The linear extrusion feature facilitates the coordinated work of upstream and downstream equipment. Since the leakage flow rate of the gear pump is small, the conveying capacity of the pump is basically linearly related to the rotational speed. After the rotational speed of the gear pump changes, the flow rate can be accurately known. Since the working speed of the upstream and downstream equipment and the gear pump can be determined, the gear pump The pressure, temperature and other information data collected at the inlet and outlet realize the online monitoring and feedback control of the entire extrusion process of the FRPP pipe.