Reverse roll coating

Reverse roll coating is a roll-to-roll coating method for wet coatings. It is distinguished from other roll coating methods by having two reverse-running nips. The metering roll and the applicator roll contra-rotate, with an accurate gap between them. The surface of the applicator roll is loaded with an excess of coating prior to the metering nip, so its surface emerges from the metering nip with a precise thickness of coating equal to the gap. At the application nip, the applicator roll transfers all of this coating to the substrate, by running in the opposite direction to the movement of the substrate, wiping the coating onto the substrate.