How to improve the dimensional accuracy in the lampshade PC profile extruding process?

The controlling pressure of the plastic extruding machine is affected by various factors, and it will result in a large fluctuation, which will definitely affect the dimensional accuracy of the extrusion PC profiles. How do we handle this situation?

What is the function of a melting pump?

Melting pump is a kind of positive conveying equipment with high-precision gear gap and volume structure design, make stable and balanced extrusion possible. It has been widely used in extrusion profile processing in chemical fiber, price bar, PC lamp cover, acrylic lamp cover sheet, compound extrusion, and other production.

If we install a melting pump between the extruder and the die, it can be used to stabilize the pressure fluctuation of the extruder, making linear extrusion possible, thereby improving the dimensional accuracy of plastic extrusion products and increasing the output of the extruder.

How does it improve the extruding process?

1. It can realize stable extrusion, improve the dimensional accuracy of extruded plastic products such as polycarbonate extrusion profiles, and reduce the defective rate.

During the extrusion process, it is inevitable for such situations such as uneven feeding of materials, fluctuations in the barrel and head temperature, and pulsation of screw speed. The use of a melt gear pump can eliminate the feeding error, greatly reduce the fluctuations transmitted by the upstream process, quickly enter a stable working state, improve the dimensional accuracy of the extruded product, and reduce the reject rate.

2. To increase productivity and achieve low-temperature extrusion, and to extend the life of the machine. Since the extruder is equipped with a polymer melting pump, the decompression function of the extruder is transferred to a gear pump. The extruder can work at low pressure and low temperature with low leakage flow and high output in extruding processing.

3. With linear extrusion, it is easy to coordinate the upstream and downstream equipment. Because the gear pump has less leakage flow, the pump’s delivery capacity and speed are basically linear. After the speed of the gear pump is changed, its flow rate can be accurately checked out.
Because the working speed of the upstream and downstream equipment and the gear pump can be determined. Information such as pressure and temperature collected at the inlet and outlet can realize online monitoring and feedback control of the entire extrusion process.

In the temperature response control, if the temperature rises rapidly, the stable value will be required in a stable mode. The temperature system has non-linearity, a large time constant, and an undetermined system. The difficult task of modeling and controlling is complex in the real system, especially, when implementation issues are considered. The conventional controllers require restrictive assumptions to design the plant model.

H.D.Plastics has more than 10 years of extruding industry experience with sophisticated technical skills, we always adapt to the most updated extrusion technology to provide our customers with high-quality extrusion profiles.