HDPE is a highly crystalline, non-polar thermoplastic resin. The appearance of the original HDPE is milky white, and the thin section is translucent to a certain extent. PE has excellent resistance to most domestic and industrial chemicals, and certain types of chemicals will cause chemical corrosion, such as corrosive oxidizers (concentrated nitric acid), aromatic hydrocarbons (xylene) and halogenated hydrocarbons (carbon tetrachloride) ). The polymer is non-hygroscopic and has good water vapor resistance for packaging purposes. HDPE has good electrical properties, especially the high dielectric strength of the insulation, making it very suitable for wires and cables. Medium to high molecular weight grades have excellent impact resistance at room temperature or even down to -40F. HDPE pipes can be manufactured in a wide range of different processes including, for example, sheet extrusion, film extrusion, pipe or profile extrusion, blow molding, injection molding and rotational molding. Grades for extrusion production generally have a melt index of less than 1 and a medium to broad MWD. During processing, low MI can obtain suitable melt strength. Wider MWD grades are more suitable for extrusion because they have higher production speeds, lower die pressures and a reduced tendency to melt fracture.
