Fast stabilization of web tension in drying process of roll-to-roll printing equipment for printed electronics.

In roll-to-roll printing for the fabrication of flexible printed electronic devices, it is important to minimize the tension variation of the web because the tension variation strongly affects register errors and the quality of the printed devices. Moreover, the high drying temperature required to sinter functional inks causes shrinkage of the plastic web, which yields severe register errors. After the drying process, the web tension should increase, elongating the web, which contracts because of the drying process. Once the shrunken web recovers its original length by elongation, the tension stabilizes at a higher value. This steady-state stabilization of the web tension requires a long time, corresponding to the time constant between two printing units, which could increase the production time. In this study, a faststabilization method for web tension in the drying process is proposed to reduce the time required for the stabilization of the tension. For the fast stabilization, a dancer system is introduced, and the variation in the tension is used as a reference value for the tension stabilization. The proposed method is verified by simulations and experiments using actual roll-to-roll printing equipment. [ABSTRACT FROM AUTHOR]