Practical design guidelines for the development of high-precision roll-to-roll slot-die coating equipment and the process

This paper proposes practical design guidelines for roll-to-roll (R2R) slot-die coating equipment with a precision mechanism enabling high-accuracy coating performance. The equipment is developed for specially fabricating organic photovoltaic devices. An R2R transportation module (capable of unwinding, in-feeding, out-feeding, and rewinding), a slot-die coating module, a far-infrared drying module, and a cleanliness control module are incorporated into the equipment. When used to apply an organic solution, the developed equipment can provide an operating tension of 2.3%-11.3%, a coating velocity of 2-7 m/min, a coating thickness of 28-95 nm, a uniformity of 8%-23%, and a roughness of 2.86-7.71 nm. A review of this equipment on the basis of theoretical and experimental approaches is included in the detailed equipment specifications and design guidelines for R2R slot-die coating machines.