Blow Molding is an umbrella term for forming hollow plastic parts by inflating a viscous plastic tube, or parison, until it fills a mold and forms the desired shape. Think of it like inflating a balloon inside of a water bottle.
There are three main types of blow molding: Injection Blow Molding, stretch blow molding, and extrusion blow molding. Injection and stretch blow molding are often used to create water bottles, cosmetic containers, and other small hollow parts. Extrusion blow molding is used to create medium to large hollow parts with complex geometries or highly technical requirements such as DEF tanks, HVAC ducts, and lawn mower seats.