Blow Moulding is a specific manufacturing process by which hollow plastic parts are formed
and can be joined together. It is also used for forming glass bottles or other hollow shapes.
The air pressure then pushes the plastic out to match the mold.
Extrusion blow moulding, injection blow moulding, and injection stretch blow moulding are
the three main types of blow moulding.
The blow moulding process starts with softening the plastic by heating it and shaping it
into a parison or, in the case of injection and injection stretch blow moulding, a preform.
The parison is a plastic tube with a hole in one end through which compressed air can pass.
After that, the parison is clamped into a mould and air is blown into it. The plastic is
then pushed out to match the mould by the air pressure.