Characteristics and specifications of PE materials PE (polyethylene) is a thermoplastic resin. According to the polymerization method, the molecular weight and chain structure of PE are different. PE is divided into high-density HDPE, low-density LDPE and linear low-density LLDPE.How is LDPE different from HDPE? Compared with HDPE, LDPE is softer and easier to melt at a lower temperature.LDPE is used in sandwich bags... and other products.HDPE is harder, has higher chemical resistance and can withstand higher temperatures.(120°C for short time and 110°C for continuous) HDPE is widely used for plastic pipes..etc.