A hydraulic cylinder drives segmented mandrel blades outward until they press evenly against the coil's inner diameter. This positive grip lets the decoiler carry the full coil weight and rotate the coil as the press line pulls strip forward, while a braking or tension-control system keeps the strip taut between the coil and the straightener or feeder.
Because expansion force comes from hydraulics rather than manual bolts, one operator can load a multi-ton coil in a fraction of the time. When the coil is finished, the mandrel retracts, the tail is secured, and the next coil is positioned for a fast changeover. On heavy lines, an optional coil car raises the coil from the floor, aligns it to the mandrel center, and removes the need for repeated crane spotting.
