In blow molding, what is the initial form of plastic called?

In blow molding, the initial form of plastic is referred to as a parison. This is a tubular piece of plastic that is formed from molten plastic during the blow molding process. The parison is created typically by extruding molten plastic through a die, which shapes it into a consistent tube. Once the parison is formed, it is placed into a blow mold, and air is introduced to expand the parison against the mold walls, thereby shaping it into a hollow object.

Understanding why parison is the correct term is essential because it relates directly to the processes involved in creating hollow plastic structures, such as bottles and containers. The parison serves as the starting point for these products, distinguishing it from other terminologies related to plastic manufacturing. The component created in the initial stages of preparation, like a preform, is typically used in a different context, such as injection molding, where it serves a different role altogether.