At first many focused on roll-to-roll (R2R) production of multilayer barrier films. The idea was that high web speeds and wide web widths together with an intrinsically low bill of materials would enable the driving down of the cost of barriers, thus helping unlock the potential of many applications including organic photovoltaics (OPVs), OLED lighting, and flexible OLED displays. This approach however has thus far proved too difficult. Most implementations were on narrow web machines and achieved reported champion results only at very low web speeds.
Furthermore, the entire machine engineering had to be adapted to minimize electrostatic build-up, to achieve uniform heat distribution, and, most challengingly, to avoid or at least minimize contact with the coated side of the film during film rolling or wind-up. Many innovative approaches were proposed and developed. However, few crossed the chasm towards large-web format. In addition, the need for a highly-impermeable and flexible adhesive was an additional disadvantage of this approach. Critically, the main variable in the cost of production here was yield which also affects web speed (due to film quality). Given the lack of substantial existing markets, the producers struggled to find enough production learning opportunities to assess and to improve their yield. As such, real validation was not demonstrated.