Rewinds fall into two categories, either surface or centre, each needing different control requirements.
When surface rewinding, it is possible to use the intermediate controller model as both applications are controlled by speed trim methods. However centre re-winders are usually operated in torque mode, and the controller must give a signal that is a function of the rewind reel diameter to determine the correct torque to be applied.
Webs of a slippery nature or having an uneven cross section thickness cause problems when centre rewinding. To obtain good rewound reels, the starting tension must be reduced as the rewind diameter increases. This action is known as “TAPER TENSION”.