MDPE (medium-density polyethylene) and HDPE (high-density polyethylene) are both plastic materials made by polymerizing ethylene monomers. They play different roles in pipelines, have their own unique application fields, and have obvious differences. This article mainly introduces the difference between MDPE vs HDPE and its application in the pipeline field.
Difference between MDPE vs HDPE
Molecular structure
MDPE: There are more branches on the molecular chain, and the cross-intermolecular force is small, so the crystallinity is low.
HDPE: There are fewer branches on the molecular chain, the cross-intermolecular force is large, the crystallinity is high, and the density is also high.
Physical properties
Density: The density range of MDPE is 0.9260.940g/cm³, while the density range of HDPE is 0.9410.965g/cm³.
Flexibility and toughness: MDPE has good flexibility and toughness, while HDPE has higher rigidity and hardness.
Heat resistance: Although both have good heat resistance in high temperature environments, HDPE has stronger heat resistance and can withstand higher temperatures.
Chemical resistance: Both MDPE and HDPE have good chemical resistance and can resist corrosion from many acids, alkalis and solvents.
Cost
Cost: The cost of MDPE vs HDPE pipes is affected by many factors such as raw material prices, production processes, and market demand. Generally speaking, the cost of HDPE pipes may be slightly higher than that of MDPE pipes due to their excellent performance and wide range of applications. However, in specific applications, comprehensive considerations need to be made based on actual needs and budgets.
Environmental protection
Environmental protection: Both MDPE and HDPE pipes are environmentally friendly materials and can be recycled and reused. When the pipes are abandoned or replaced, the impact on the environment can be reduced through recycling.
Maintenance
In terms of maintenance, both MDPE and HDPE pipes have good durability and low maintenance costs. However, it should be noted that regular inspections and maintenance are still required during use to ensure the normal operation of the pipe system and extend its service life.
The role of MDPE and HDPE in the pipeline field
MDPE pipeline
Due to its good flexibility and toughness, MDPE pipeline can provide a certain elastic deformation in the pipeline system, thereby adapting to stress changes caused by external factors such as soil movement and temperature changes.
MDPE pipeline has excellent low-temperature resistance, can maintain stable performance in low-temperature environments, and is not easy to become brittle or rupture.
HDPE pipeline
Due to its high strength, high rigidity and excellent corrosion resistance, HDPE pipeline can withstand greater pressure and load, ensuring the stability and safety of the pipeline system.
HDPE pipeline has good corrosion resistance to a variety of chemical substances, and can resist erosion by substances such as acids, alkalis, and salts, thereby extending the service life of the pipeline.
Application of MDPE pipe and HDPE pipe
MDPE pipe
MDPE pipeline is mainly used to transport gaseous substances, such as artificial coal gas, natural gas, liquefied petroleum gas, etc. Due to its flexibility and low-temperature performance, MDPE pipeline also has certain application advantages in occasions where flexible connections are required.
MDPE pipeline is also suitable for some occasions that need to withstand certain deformation without rupture, such as drainage pipes, agricultural irrigation pipes, etc.
HDPE pipe
HDPE pipes are widely used in municipal engineering water supply systems, indoor water supply systems of buildings, outdoor buried water supply systems, and old pipeline repairs.
In the field of petrochemicals, HDPE pipes are used to transport various corrosive media and oil products due to their excellent corrosion resistance and wear resistance.
HDPE pipes are also suitable for agricultural irrigation, mining fine particle solid transportation, and postal and telecommunications.
