Blow moulding a shape is a common industrial process. The example shown below is of the production of a plastic bottle. The plastics normally used in this process are: polythene,PVC and polypropylene.
The process is similar to injection moulding and extrusion.
1. The plastic is fed in granular form into a 'hopper' that stores it.
2. A large thread is turned by a motor which feeds the granules through a heated section.
3. In this heated section the granules melt and become a liquid and the liquid is fed into a mould.
4. Air is forced into the mould which forces the plastic to the sides, giving the shape of the bottle.
5. The mould is then cooled and is removed. The article is sort out by www.china-leshan.com