Application Case

Polyethylene plastic pipes are mainly divided into two categories: high-density polyethylene HDPE(low pressure polyethylene) and low density polyethylene LDPE(high pressure polyethylene). The application of polyethylene materials is very broad, and the pipe field is only one aspect of the application field of polyethylene. Due to the differences in physical properties of HDPE and LDPE, the two materials are different in the field of pipe application: Low density polyethylene (LDPE) has good flexibility. However, the compressive strength is low, so it can only be used for low-pressure small-diameter pipes, which are often made into coils for rural water transformation and some non-long-term use occasions. High-density polyethylene (HDPE) is widely used in the field of pressure pipes (such as PE80, PE100; The popular explanation of PE80 is that the material is not damaged at 20℃ under continuous pressure for 50 years, and the minimum required strength of the pipe wall is 80MPa, and so on. In the early stages of the development of plastic pipes, the use of polyethylene pressure pipes is much smaller than polyvinyl chloride, high-performance, high-strength polyethylene pipes. With the emergence of new HDPE materials and new technologies, this difference in cost (weight) has changed greatly, with the emergence of the second generation polyethylene pipe material (equivalent to PE80) and the third generation polyethylene pipe material (equivalent to PE100), under the same diameter of 200 and the same pressure level and conditions, The weight of polyethylene pipe of the same length is only 93% of the weight of UPVC pipe. Therefore, the second and third generation of polyethylene pipe materials not only significantly improve the minimum required strength of PE, but also improve the resistance to environmental stress cracking performance, with significant anti-crack rapid growth ability, more importantly, under the same pressure can reduce the wall thickness and increase the transmission cross section. Under the same wall thickness, the pressure used is increased to improve the transportation capacity (for example, under the same wall thickness, the transportation pressure of PE100 polyethylene pipe can reach 10 bar, and the transportation pressure of PE80 polyethylene pipe can only reach 8 bar).

At present, the fourth-generation polyethylene pipe material PE125 has been successfully developed, which can predict that the polyethylene pressure pipe with larger diameter and more pressure economy has a broad field of use.