Why was "tantrum" trending last week?
a technique for making hollow objects, such as bottles, by injecting air under pressure into a molten mass of glass or plastic and shaping the object within a mold
The hot element used in blow molding is called a parison.
in glass production, method of forming an article of glass by blowing molten glass into a mold. This operation is performed with the aid of a hollow metal tube that has a mouthpiece at one end. A gob of molten glass gathered onto the opposite end of the tube is enlarged by a bubble of air blown into it through the tube. This preliminary shape is then lowered into a mold and inflated by blowing until it has assumed the desired shape and pattern. The mold may be constructed of one piece, in which case it is sheared off the glass article, or it may be an open-and-shut device comprised of two parts, which allows the mold to be removed and reused