Reverse roll coaters consist of 3 or 4 roll, configured for metering the coating thickness and transferring it to the substrate. They all have a metering roll and an applicator roll, both rotating in reverse wiping direction of the moving web and back-up roll. There are a variety of roller arrangements available for this type of coaters, and they can be configured as either pan fed or nip fed.
They can be selected for water based, solvent based and hot melt coatings. The pan fed design will be preferred for lower viscosity coatings and equipped with a fourth roller, for coating pick-up and transfer to the applicator roll. The nip fed design will be ideal for coatings with higher viscosity, and equipped with rail mounted edge dams, for easily adjusting the coating width.