Final answer:
In blow molding, the hollow plastic tubes that are used are called a parison, which is essential for creating various hollow plastic products.
Step-by-step explanation:
The hollow plastic tubes used in blow molding are called a parison. Blow molding is a manufacturing process that involves inflating a hot, hollow thermoplastic parison inside a closed mold, so it takes the shape of the mold cavity. This technique is used to manufacture hollow plastic products such as take-out trays, foam packaging peanuts, and CD cases. The term parison is specifically associated with the blow molding segment of plastic manufacturing, and should not be confused with related processes such as injection molding, extrusion, or drawing.