The ribs are caused by flow instability bascially.The unlevel ribs caused by film-splitting are print to material surface in forward-roll coating.

• 在带漆辊与涂覆辊间的顺辊涂装过程中，因涂膜分离流场不稳定而出现在涂覆辊表面之流纹，在来不及流平的情况下转印到底材表面。