Blow molding is the process of manufacturing hollow containers like Bottles, Jerry cans, Jars, Drums, tanks etc. from plastics. The most common blow moulded plastic resins are HDPE, LDPE, PVC, PET, PP etc. The basic process is to heat up the raw material to a molten state and blowing to the shape of cavity of the mould by air pressure. The blowing of air made the process known as blow molding.More details at shreeplas.com