Features of plastic extrusion molding

Plastic extrusion molding refers to a molding method in which plastic is melted and plasticized by the shear force and pressure of the rotating screw in the heated barrel of the extruder, and then becomes a continuous long product with a certain cross-sectional shape through an extrusion die. The process includes raw material mixing, extrusion, cooling and shaping, drawing and cutting, etc. Let's take a look at the functional characteristics of plastic extrusion molding.

Features of plastic extrusion molding:

1. It can achieve stable extrusion, improve the dimensional accuracy of extruded products, and reduce the 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 extruded products, and reduce the scrap rate.
   

2. Increase output, reduce energy consumption, realize low temperature extrusion, and prolong the life of the machine. Since the extruder is equipped with a polymer melt pump, the decompression function of the extruder is transferred to the gear pump, and 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.

3. With linear extrusion characteristics, it is convenient for upstream and downstream equipment to work in harmony. Since the leakage flow of the gear pump is small, the conveying capacity of the pump has a linear relationship with 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 online monitoring and feedback control of the entire extrusion process.

The above content is the functional characteristics of plastic extrusion molding that Xiaobian introduced to you. The main process parameters include extrusion temperature, extruder screw speed, traction speed, etc. Mainly used to produce tubes, rods and profiles. With the necessary auxiliary machinery, thicker plates can be produced, especially special-shaped plates such as corrugated plates, and products compounded with other materials, such as wires, composite films, etc. With special machine head and setting equipment, it can also produce net, bamboo tube, corrugated tube and other products.