Advanced taper tension method for the performance improvement of a roll-to-roll printing production line with a winding process

A center-wound roll is one of the most suitable and general schemes in a winding mechanism of roll-to-roll systems. In general, the quality of a wound roll can deteriorate significantly due to telescoping and starring defects. This paper presents an advanced taper tension method for reducing such defects. We observed that the starring is closely related to the distribution of radial stresses within the rolls, and the risk of telescoping increases during winding at high operating speeds. Based on correlations, a mathematical model of telescoping caused by transverse tension distribution is developed. To prevent a winding failure, the profile of the taper tension is dynamically updated with respect to the winding radius ratio. The approach allows for the minimization of telescoping in the initial stage of winding and the prevention of starring defects in the wound rolls. In addition, the performance of the proposed method is experimentally verified with actual roll-to-roll printing systems.