The  Basic  Process  Of  Blow  Molding

   Blow Molding is a highly developed molding technology developed back in the late 1800's to produce celluloid baby rattles. It is best suited for basically hollow parts (such as plastic bottles) with uniform wall thicknesses, where the outside shape is a major consideration.
    The first polyethylene bottle was manufactured using the blow molding process in December of 1942. This was the real beginning of a huge industry which currently produces 30 to 40 billion plastic bottles per year in the U.S. alone.

1. A thermoplastic resin is heated to a molten state
2. It is then extruded through a die head to form a hollow tube called a parison.
3. The parison is dropped between two mold halves, which close around it.
4. The parison is inflated.
5. The plastic solidifies as it is cooled inside the mold.
6.The mold opens and the finished component is removed.