Blow molding is a molding method in which a resin called a parison, which is a pipe made of a molten thermoplastic resin, is blown out and blown out to take out after cooling.Conventionally, it was used to manufacture bottle containers for eye drops, medicines, cosmetics, foods, detergents, etc. Recently, its features such as cost performance, high rigidity and light weight have been evaluated, and various types of products, mainly automobile parts, have been evaluated. Application fields are also expanding to industrial parts.
Blow molding (or moulding) is a manufacturing process for forming and joining together hollow plastic parts. It is also used for forming glass bottles or other hollow shapes. In general, there are three main types of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding.
The blow molding process begins with melting down the plastic and forming it into a parison or, in the case of injection and injection stretch blow molding (ISB), a preform. The parison is a tube-like piece of plastic with a hole in one end through which compressed air can pass.
The parison is then clamped into a mold and air is blown into it. The air pressure then pushes the plastic out to match the mold. Once the plastic has cooled and hardened the mold opens up and the part is ejected. Water channels are carved into the mold to assist in cooling.