What is the primary feature of the blow molding process?

The primary feature of the blow molding process is the clamping of molds around a parison. In blow molding, a hollow tube of plastic called a parison is heated and then air is blown into it, causing it to expand and take the shape of the mold. The process starts with the parison being formed and clamped into a mold. Once the mold is closed, air is introduced, which forces the plastic to conform to the cavity of the mold. This is crucial in producing hollow objects such as bottles and containers.

Heating plastic to a liquid state is an important step in the manufacturing of many plastic products, but it is not specific to blow molding. This step is relevant in various plastic molding processes, such as injection molding and extrusion. Injecting molten material into molds is typical of injection molding rather than blow molding, where the process relies on expanding a parison rather than injecting material into a closed mold. Extruding plastic into sheets is related to another process called extrusion, which is distinct as it does not involve the formation of hollow objects but rather flat, continuous sheets or shapes.