In recent years，perovskite solar cells have gained attention due to their lightweight and flexible characteristics，making them suitable for various applications．These film-type solar cells are often produced using Roll-to-Roll production with flexible polymer substrates such as polyethylene terephthalate or polyimide．However，during web transport in R2R systems，defects like troughs and wrinkles can occur，leading to reduced product quality．To address these issues，curved axis rollers，which apply a spreading force in the cross direction，have been developed．This study aims to investigate the basic mechanism of web spreading using curved axis rollers．Experiments were conducted by varying the roller's angle of bend direction and wrap angle while measuring the spreading amount using a slitted web．Contact pressure distribution between the web and roller was measured using pressure-sensitive film，and further validated through finite element method simulations．Results showed that the maximum spreading amount decreased with increasing wrap angle，and optimal angle of bend directions differed depending on the wrap angle．Additionally，contact pressure distributions varied significantly with the angle of bend direction，and FEM analysis showed good agreement with experimental results．These findings indicate that the curved axis roller’s spreading effect is strongly influenced by angle of bend direction and contact conditions，and FEM is an effective tool for analyzing its mechanism.
Yoshida et al. (Wed,) studied this question.