Coating

FLOW-3D has been used by coating researchers in industry and academia for machine design research, process window development, and optimization. Understanding coating physics at the micron scale can be difficult due to the complex nature of coating fluid rheology and its interaction with substrates and dies. FLOW-3D provides high fidelity modeling for understanding the effects of surface tension, wall adhesion, solute transport, density driven flows, and phase change.

This FLOW-3D simulation of a forward roll coating process captures a ribbing defect due to a high capillary number. The model incorporates the effects of surface tension and viscosity as the backing rollers draw the fluid through a 400 micron nip. The simulation is based on research by Lee, et al [1]. The accurate prediction of the onset of ribbing allows researchers to identify and correct process parameters to avoid defects.

Reference

[1] Lee, J. H., Han, S. K., Lee, J. S., Jung, H. W., & Hyun, J. C. (2010). Ribbing instability in rigid and deformable forward roll coating flows. Korea Australia Rheology Journal, 22(1), 75-80.