1. HDPE high-density polyethylene is an opaque white powder with a softening point of 125 to 135 °C and a service temperature of up to 100 °C; hardness, tensile strength and creep are better than low-density polyethylene; wear resistance, Good electrical insulation, toughness and cold resistance; good chemical stability, insoluble in any organic solvent at room temperature, corrosion resistance to acid, alkali and various salts.
2. PP Polypropylene is a polymer obtained by addition polymerization of propylene. It is a white waxy material with a transparent and light appearance. The density is 0.89～0.91g/cm3, flammable, the melting point is 165℃, and it softens at about 155℃. The operating temperature range is -30～140℃.