Process considerations, process challenges and manufacturing systems for roll-to-roll processing

In roll-to-roll processing, the feeding speed of substrate ranging from several meters to several tens meters per minutes are required for some processes, such as roll-to-roll coating or gravure printing; reducing the speed will lead to other problems. On the other hand, some other processes need prolonged dwelling or holding time, such as thermal embossing. In the case of integrating different processes (for example, embossing and printing) into one roll-to-roll processing line, it is necessary to synchronize the feeding speeds of different processes. In this study, we will focus on thermal embossing process, discuss how the process speed, holding time will affect the fidelity of formed structures. Based on our investigation and comparison, we identified the problems of roll-to-roll thermal embossing, and developed a novel roll-to-roll embossing system. The developed system consists of two metallic belts — the top belt used for embossing template and the bottom belt for carrier. The developed system allows active driving from both sides of polymer films; it also provides an extended template-film contact time even with high speed roll-to-roll thermal embossing. This allows the roll-to-roll embossing to be integrated with other roll-to-roll manufacturing processes such as printing or coating.