Fraunhofer FEP will present test results for its barrier and transmission films, which have been exposed to weather for one year, at SVC 2015 (Santa Clara, USA, 25th – 30th April).
Flexible electronic components are seeing increasing use in both new and existing applications. However, these components must be protected against environmental influences, such as UV radiation and corrosive gases; they are commonly encapsulated with glass or a coated film in order to remain functional.
Fraunhofer scientists are working on surface treatments and plastic film coatings to achieve the required encapsulation properties. These include low water vapour/oxygen permeability, as well as UV radiation protection and high transparency for visible light. Unlike previous tests, Fraunhofer’s work focuses on permanent exposure to the weather.
Fraunhofer FEP, together with Fraunhofer ISC and Fraunhofer IVV, has succeeded in developing encapsulation using weathering-resistant fluoropolymers. An ETFE film was upgraded with a permeation barrier layer system as part of the research. Fraunhofer’s John Fahlteich will introduce weathering-resistant encapsulation systems on ETFE film at SVC 2015; this film will have water vapour permeation in the high barrier range, as well as integrated UV protection.
‘Significant’ progress was made in light transmission and the efficiency of the encapsulated elements, using a process for the optical anti-reflection coating of surfaces. The process is based on plasma-supported nanostructuring of large surfaces; these can be realised at a low cost with roll-to-roll processing, says Fraunhofer. Transmission values of 96.3% were achieved on ETFE with an anti-reflective coating on one side, and 98.7% with the coating on both sides. A positive side-effect was also found: the nanostructures reduce the build-up of surface dirt.
Fraunhofer’s coatings could have implications for outdoor flexible or curved signs, such as those from E Ink/Global Display Solutions (Display Monitor Vol 20 No 9). (TA)