PE has many extrusion applications, such as wires, cables, hoses, pipes, and profiles. The application range of pipe materials ranges from small section yellow pipes for natural gas to thick walled black pipes with a diameter of 48 inches for industrial and urban pipelines. The use of large-diameter hollow wall pipes as substitutes for concrete rainwater drainage pipes and other sewer pipelines is growing rapidly.
Sheet metal and thermoforming: Many large picnic refrigerators have thermoformed liners made of PE, which is tough, lightweight, and durable. Other sheet materials and thermoformed products include mudguards, tank liners, basin guards, transport boxes, and tanks. A rapidly growing application of sheet materials is in plastic film or pond bottom villages, based on MDPE's toughness, chemical resistance, and impermeability.
Blow molding: More than one-third of HDPE sold in the United States is used for blow molding purposes. These range from bottles containing bleach, engine oil, detergent, milk, and distilled water to large refrigerators, car fuel tanks, and cans. The characteristic indicators of blow molding grades, such as melt strength, ES-CR, and toughness, are similar to those used for sheet and thermoforming applications, so similar grades can be used.
Injection blow molding is commonly used to manufacture smaller containers (less than 16oz) for packaging drugs, shampoos, and cosmetics. One advantage of this processing is that the production of bottles automatically removes the edges and corners, without the need for post-processing steps like typical blow molding. Although some narrow MWD grades are used to improve surface finish, medium to wide MWD grades are generally used.
