Effect of shim configuration on flow dynamics and operability windows in stripe slot coating process

The slot coating method is a strong candidate for the manufacture of secondary batteries and electrodes for electronics. For the production of such devices, one may need to coat multiple lanes simultaneously which is usually done by implementing specially designed stripe shim inside the die manifold. The effects of shim configurations on the stripe-patterned coated film were analyzed in this study. We employed computational and experimental analyses to estimate flow patterns and corresponding desirable operating condition changes for uniform, converging and diverging slit channels. It was found that the slit channel shape, which is determined by the shim design, can manipulate the die-exit velocity distribution, capable of controlling edge shape of the crossflow film thickness profile. However, other than producing a uniform channel, this might decrease the scope of operability windows due to the aggravation of bead break-up near the edge of the slit channel.