Extrusion blow molding is typically a six-step process that begins when dry resin is extruded and formed into a hollow, tube-shaped parison. A parison is a tube of molten plastic that is extruded downwards from the die. The plastic must have good melt strength to hold its form.

The parison is then inflated in the mold with compressed air. The quenched, mold-shaped part is extracted from the mold and the flash removed. Secondary operations include trimming the finish area for lid application and labeling.