An injection blow molding machine usually has three mould stations, tube-like parisons, or preforms, are injection moulded at the first station, while still hot, these are transferred on mandrels to the blowing station where they are inflated in a set of blow moulds. The blown containers are then transferred to the ejection station.
Because the parisons are injection moulded, injection blown containers have a high quality neck finish and a better surface finish than extrusion blown containers. Tooling costs are high because a preform mould and blow mould are required. The process is usually used for smaller containers and finds its main applications in the pharmaceutical and cosmetics field.