Simulation analysis of the start-up process of Carreau-type fluid slot die coating

The start-up process is important for ensuring the end quality of slot coating products. This study uses ANSYS Fluent to explore the start-up process of slot coating with Carreau-type non-Newtonian fluid. The relationship between the pressure change in the coating bead at the slot outlet and the stabilization process of the coating bead is analyzed, and the effects of the downstream die lip angle and downstream die lip length on the size of the coating bead are discussed. The simulation results show that the pressure at the slot outlet directly affects the stabilization of the coating bead, and accelerating the coating bead stabilization pressure can accelerate the start-up process. When other parameters remain unchanged, reducing the downstream die lip angle or length can reduce the size of the coating bead, thereby accelerating the start-up process.