How does the working state of the extruder determine the physical properties of PE pipes?

During the operation of the PE pipe extrusion production line, the working state of the extruder is like a pair of "invisible hands", quietly but profoundly shaping the physical properties of PE pipes. This close connection runs through the entire production process from the raw materials entering the extruder to the pipe forming. Understanding the mechanism of action is crucial to controlling the quality of PE pipes.

The PE pipe extrusion production line takes the extruder as the core to convert polyethylene raw materials into pipe products. At the beginning of production, the proportioned polyethylene resin and additives enter the extruder, and under the synergistic action of the screw and the barrel, the transition from solid to viscous flow is started. The screw uses the propulsion force of the thread during rotation to transport the raw material toward the die head. The heating device outside the barrel and the friction heat generated by the rotation of the screw work together to cause the raw material to heat up and melt. In this process, the working state of the extruder directly determines the plasticization quality of the material, and the plasticization quality is directly related to the physical properties of the PE pipe.

A high-quality extruder can achieve an efficient and uniform plasticizing process. When the extruder is running stably, factors such as the rotation speed of the screw, the temperature control of each section of the barrel, and the structural design of the screw cooperate with each other to fully mix the materials in the extruder. For example, the special structures such as the aspect ratio of the screw, the change of the screw groove depth, and the barrier screw fins can enhance the shearing and mixing effects of the materials, so that the various components in the raw materials are evenly distributed, while avoiding polymer degradation due to excessive shearing. Under such a good working condition, the material extruded from the extruder die head forms a stable and uniform melt, laying the foundation for the subsequent molding of high-quality pipes. The PE pipes finally produced have good mechanical properties, high tensile strength, and can withstand large tensile forces without breaking; have excellent impact resistance, and are not easily damaged when hit by external forces; and have good resistance to environmental stress cracking, even under complex environmental conditions, they can maintain a long service life.

However, when the extruder is not in good working condition, a series of problems will follow. If the screw speed is too fast, the material will stay in the barrel for too short a time and cannot be fully melted and plasticized. At the same time, too high a speed will also produce too much shear force, resulting in local overheating and degradation of the material. If the barrel temperature is not properly controlled, the temperature of some parts is too high or too low, which will also cause uneven plasticization of the material. After the poorly plasticized material is extruded, defects such as pores and impurities are likely to occur inside the PE pipe. The presence of pores weakens the structural strength of the pipe, making it easy for the pipe to break when it is under pressure; impurities may become stress concentration points, reduce the impact resistance of the pipe, and cause leakage and other problems during use, seriously affecting the quality and reliability of the pipe.

The coordinated work of the PE pipe extruder and subsequent equipment will also affect the physical properties of the PE pipe. The stable extrusion volume of the extruder is the prerequisite for ensuring uniform wall thickness and consistent pipe diameter. If the working state of the extruder is unstable and the extrusion volume fluctuates, it is difficult to produce pipes with qualified dimensional accuracy even if the mold and traction equipment perform well. The dimensional accuracy of the pipe is closely related to the physical properties. Uneven wall thickness will lead to uneven force on various parts of the pipe, reduce the overall load-bearing capacity, and further affect the tensile strength and pressure resistance.

It can be seen that in the PE pipe extrusion production line, the working state of the extruder determines the physical properties of the PE pipe in all aspects through direct intervention in the plasticization process of the material and indirect influence of the coordinated work with subsequent equipment. Whether it is the pursuit of high-strength and high-toughness high-quality PE pipes, or the guarantee of the safety and reliability of pipes in actual applications, it is necessary to attach great importance to the working state of the extruder, starting from screw design, temperature control, equipment coordination and other aspects to ensure the stable and efficient operation of the extruder, so as to produce PE pipe products that meet market demand and quality standards.