The huge variety of different coating applications ranging from highly uniform optical films to mechanically rugged protection layers require coating thicknesses between some 10 nm up to some mm. Moreover the rheological parameters of the coating liquids may vary from high viscous pastes to fluids more fluent than water. No single coating technique is fit to cover this full range of applications.
Different coating techniques will be presented giving a short explanation of their function and summarizing their respective pros and cons.
Especially slot die coating will be emphasized as slot dies frequently replace other techniques because of their unique advantages to be a closed and premetered system. Most recent developments in intermittent coating (start-stop-coating) will be shown.
In almost any case the coating liquid has to be cured or dried after coating. Whilst curing (e.g. by UV if applicable) is usually no big issue, drying may be rather complicated and expensive. Different drying techniques are presented and their applicability is discussed.