Blowing mold also known as hollow blow molding, a rapidly developing plastic processing method.Blow molding technology began to be used to produce low density polyethylene bottles during the second World War in the late 1950s. With the birth of high density polyethylene and the development of blow molding machine blow molding technology has been widely used.The volume of hollow container can reach thousands of liters, some production has been controlled by computer.Plastics suitable for blow molding include polyethylene, polyvinyl chloride, polypropylene, polyester and so on, which are widely used as industrial packaging containers.According to the method of making the billet, blow molding can be divided into extrusion blow molding and injection blow molding.