Winding and Slitting Lines

Shafts, chucks, brakes and control equipment needed at the unwind and rewind of roll-fed lines such as slitting, laminating, profile wrapping and textile machines.

A winding line is any machine that unwinds material from a roll, processes it and winds it onto a new roll: slitter rewinders, laminating and coating lines, profile wrapping machines, and textile and paper machines are among the most common. The material may differ, but the core challenge is the same: keeping tension, speed and web position under control while the roll diameter is constantly changing.

Key processes on winding lines

At the unwind, brake or motor torque has to come down as the roll gets smaller in order to hold the same tension. At the rewind, torque rises as the roll builds; in many applications tension is tapered gradually as the roll grows so that the inner layers are not crushed. On a slitter, a wide parent roll is cut into strips and each strip is wound onto its own core on the same shaft. Small variations in material thickness make these cores build up to different diameters, so on a shaft running at a single speed the tension varies from strip to strip.

Which equipment goes where?

Friction shaft: On a slitter rewind, it drives the cores through friction rings with controlled slip, so each strip winds at its own speed. See the friction shaft and friction rings.
Air shaft: Carries the parent roll at the unwind and single-core rolls at the rewind. Aluminium versions save weight, and on wide machines carbon fibre shafts are an option for keeping weight down.
Safety chuck: Connects the shaft to the machine and speeds up roll changes; an inside-frame safety chuck is one of the options to consider on lines of this kind.
Brake and tension control: A magnetic particle brake working with a tension controller helps hold tension steady at every roll diameter.
Web guiding: A web guide controller corrects the roll or the web laterally for a straight-edged wind.
Adapter: A mechanical aluminium adapter lets one shaft run cores of different diameters.

What to consider when selecting

The number of strips, core widths and material type determine how the friction shaft is configured.
Tension range and line speed call for the brake and controller to be selected together.
On lines with frequent roll changes, shaft weight and ease of use of the safety chuck affect productivity.
Plan spare parts in advance for wear items such as air bladders, valves and lugs.

For size options see the technical dimensions page, or request a quote for your line through our contact page.