Slot die stripe coating of low viscous fluids
Scientists have recently shown that an upper limit significantly reduces the process window for stripe coatings.
Slot die coating is applied to deposit thin and homogenous films in roll-to-roll and sheet-to-sheet applications. The critical step in operation is to choose suitable process parameters within the process window. In a new work, scientists investigate an upper limit for stripe coatings. This maximum film thickness is characterised by stripe merging which needs to be avoided in a stable process. It is shown that the upper limit reduces the process window for stripe coatings to a major extent. As a result, stripe coatings at large coating gaps and low viscosities are only possible for relatively thick films. Explaining the upper limit, a theory of balancing the side pressure in the gap region in the cross-web direction has been developed.
The study is published in: Journal of Coatings Technology and Research September 2018, Volume 15, Issue 5, pp 899–911.
