Viscoelastic phenomena in roll-to-roll manufacturing - Two case studies of industrial relevance
Abstract
In the current manufacturing industry, Roll-to-Roll (R2R) manufacturing is in high demand because of its high productivity and low cost. Many materials used for R2R manufacturing are considered viscoelastic on some time scale and they evolve with time under pressure. It is important to study their viscoelastic phenomena to understand the behavior during and after it undergoes R2R processing. In the present research, we focus on lamination and nanoimprint lithography processes. In the lamination process, two or more webs pass through the roller set where they are laminated. Once the laminated webs are set free from the laminating machine, curl can be witnessed due to the mismatch in the induced web stain. The viscoelastic nature of the laminate adhesive affects the shear deformation during and after lamination which results in mismatched strain conditions. These curls are considered defects and have always been a problem of interest. The goal is to study the parameters that affect the curl of the laminated web by developing lamination models. The optimal lamination operating parameters that would produce a curl-free laminated web for the given web and laminate adhesive are estimated. In nanoimprint lithography, once the webs are imprinted with the nanopatterns, they are stored in the form of wound rolls until they are needed in a subsequent R2R process. Due to the viscoelastic nature of the UV curable resin, the imprints experience creep when subjected to the wound roll pressure, which affects the performance of the product. The goal is to study the effect of wound roll pressures on the nanoimprinted web. With obtained viscoelastic material properties for the resin, the deformation of the nanopatterns are calculated through the time when subjected to wound roll pressures (computed using a winding model). This will help in establishing how the imprinted materials should be wound and how long they can be subjected to pressure in the wound roll before they should be unwound to limit the deformation of the nano-imprinted features.
Collections
- OSU Dissertations [11222]