Blowing moulding, also known as hollow blow moulding, is a rapidly developing plastic processing method. During World War II, blow moulding began to be used in the production of low density polyethylene bottles. In the late 1950s, with the birth of high density polyethylene and the development of blow moulding machine, blow moulding technology has been widely used. The volume of hollow containers can reach thousands of litres, and some of the production has been controlled by computer. Plastics suitable for blow moulding are polyethylene, polyvinyl chloride, polypropylene, polyester, etc. The hollow containers obtained are widely used as industrial packaging containers. According to the method of parison making, blow moulding can be divided into extrusion blow moulding and injection blow moulding, and the newly developed multi-layer blow moulding and stretch blow moulding.

The tubular plastic billet produced by extrusion or injection moulding of thermoplastic resin is placed in the opposite open die while it is hot (or heated to the softening state) and compressed air is injected into the billet immediately after closing the die, so that the plastic billet is blown up and attached to the inner wall of the die. After cooling and demoulding, various hollow products are obtained. The manufacturing process of blow-moulded film is very similar to that of hollow products in principle, but it does not use moulds. From the perspective of classification of plastic processing technology, the forming process of blow-moulded film is usually included in extrusion. During World War II, blow moulding began to be used in the production of low density polyethylene bottles. In the late 1950s, with the birth of high density polyethylene and the development of blow moulding machine, blow moulding technology has been widely used. The volume of hollow containers can reach thousands of litres, and some of the production has been controlled by computer. Plastics suitable for blow moulding are polyethylene, polyvinyl chloride, polypropylene, polyester, etc. The hollow containers obtained are widely used as industrial packaging containers.