1. Reel

The raw material—that is, the basic conductors or wires, which are a few millimeters in diameter—is supplied in the form of spools or, less commonly, wires wound onto octabins (octagonal cardboard boxes on pallets used to hold the wires) at the entrance to the extrusion line. The primary function of the pay-offs is to ensure a continuous supply of conductor, wire, or cable to the line. Depending on the application, different pay-offs are used, depending on whether the material being unwound is conductor, optical fiber (Figure 1 ), or an assembled cable to be jacketed.