Avoiding surface instability and slurry jamming
Simultaneous multilayer coating techniques are widely known, but their industrial application remains limited to narrow market sectors. One barrier to adoption may be the mismatch between industries that are familiar with such processes but have no need, and industries that have need but are not familiar. Moreover, there are application-specific technical challenges to developing multilayer-coating processes. In a new article, scientists now describe theirt resolution of two specific issues in simultaneous multilayer coating of all-aqueous highly loaded slurries for new and emerging energy applications.
Saving significant development cost
The first issue is particle jamming (associated with shear-thickening) of the highly loaded slurries in the die internals, which they alleviated by adding small amounts of viscosity modifiers without reducing the solid loading. The second issue is a Marangoni-driven surface instability that resembles top layer de-wetting, which they solved by carefully selecting surfactants to tune the dynamic surface tensions of each slurry. Both issues were resolved early in a step-wise development, saving significant development cost which in this case was driven by expensive materials.
The study has been published in Journal of Coatings Technology and Research, Volume 19, 2022.