What is Extrusion Blow Molding?

andrewcheng | Plastic | 03/21/2011

What is the extrusion blow molding process?

1. Thermoplastic is heated to a molten state.

   The molten thermoplastic is extruded vertically downwards through a die head to form a hollow tube. This hollow, molten plastic tube is called a parison.

   
   
   

   

2. Two halves of a mold closes around the parison sealing off one end while leaving the other open.

   

3. Pressurized air is blown into the parison from the open end. This forces the molten thermoplastic parison against the water-cooled mold.

   
   

   

4. The thermoplastic solidifies to the shape of the mold (with a hollow center).

   

5. The mold opens and the finished product is ejected.