Blow moulding mainly refers to the hollow blow moulding (also known as blow moulding), which is a method of forming hollow products by blowing hot-melt blanks closed in the mould with the help of gas pressure. It is a fast developing plastic moulding method. Compared with injection moulding, blow moulding has lower cost, better adaptability, good mouldability (such as low stress) and complex undulating curve (shape).

The most commonly used materials for blow moulding include polyolefins such as PE, PP, PVC and engineering plastics such as PA, PC, etc. Electricity includes elastomers, of which PE plastics are the most used. Blow moulding process can not only be used to moulding bottles with different sizes and shapes of liquids, medicines, children's toys, hot water bottle shells, etc. in daily life and industry, but also to moulding hollow industrial parts with complex shapes, especially in automobile industry. The application scope of blow moulding products involves automobiles, office equipment, household appliances, etc. Medical treatment, entertainment utensils, furniture, etc. Among them, automotive plastic fuel tank is the largest production of hollow blow-moulded automotive parts, which started production in 1973 and has accounted for 90% of the total automotive fuel tank by 2000. In recent years, blow moulding technology has been developed faster, from single-layer to double-layer and multi-layer blow moulding. Blow moulding technology has appeared many new technologies, such as extrusion blow moulding, injection blow moulding, extrusion or injection stretch blow moulding. Computer simulation technology has also played an increasingly important role in blow moulding process, and computer CAE/CAM technology has become increasingly mature. Blow moulding technology is developing towards the production of larger and more diverse hollow products, faster production speed and higher quality.