Paper cup fans, also commonly known as paper cup blanks, are the intermediate semi-finished components used in the manufacturing of disposable paper cups. It refers to a pre-printed, die-cut, fan-shaped piece of paperboard that contains all the parts needed to form a single cup:

• The Cup Side Wall: The curved, fan-shaped section
• The Cup Bottom: A separate circular piece that is attached during forming, or integrated into the blank's design
• The Glue Tab: An edge used to seal the cup once it is rolled into a cone shape

In simple terms, it is the "flat pattern" or the "parts" of a paper cup before it is finally rolled and assembled. On an automated production line, these fans are picked up by a machine, rolled into a cone, have their bottom sealed and glue tab secured, and finally have their rim curled to form a complete paper cup.