The dependence of the maximum and minimum wet thicknesses on the coating gap is derived for the slot-die coating process, under different slot-die configurations. Analytical expressions for the wet thickness and its derivative with respect to the coating gap are obtained using a simple flow model. The results indicate that, as expected, the minimum wet thickness increases linearly with the coating gap; however, the maximum wet thickness demonstrates a counterintuitive trend of decreasing as the coating gap increases, when a specific slot-die configuration is assumed. Moreover, the results are also validated by numerically solving the complete two-dimensional (2D) Navier–Stokes equation.

中文翻译：

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缝模配置对最大和最小湿厚度的涂层间隙依赖性的影响

对于不同缝模配置下的缝模涂布工艺，得出最大和最小湿厚度对涂布间隙的依赖性。使用简单的流动模型获得湿厚度及其相对于涂层间隙的导数的解析表达式。结果表明，正如预期的那样，最小湿厚度随涂层间隙线性增加；然而，当假设特定的槽模配置时，最大湿厚度显示出随着涂层间隙的增加而减小的违反直觉的趋势。此外，还通过数值求解完整的二维 (2D) Navier-Stokes 方程来验证结果。