An interesting alternative for mechanically stressed display glazing is the new anti-reflective glass from the Schott technology group. They are available under the brand name Conturan® Tough AS, more break-resistant than comparable hardened float glass and at the same time thin and light.
Conturan Tough AS offers a high anti-reflection coating, long service life and durability.
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Whether for medical or touch applications - today displays are used more and more in outdoor and industrial environments. Even toughened float glass sometimes does not withstand such increased demands or does not offer the desired safety. Schott has now developed Conturan Tough AS for this purpose. The substrate of the cover glass made of aluminosilicate glass (AS) guarantees high mechanical stability and 50 % improved break and impact strength compared to chemically toughened soda lime float glass.
The glass was optimized for chemical tempering. According to Schott, it is the only glass of its kind to allow this increase in strength through the anti-reflective layer. The glass is stable and at the same time thin and light. The thickness of the substrate is around 2.1 mm.
High Anti-Reflection Coating and Durability
Like the entire product range, the new anti-reflective lenses are coated with the tried and tested anti-reflective coating, which ensures optimum visibility of display content even in unfavourable lighting conditions. This is because the reflection is reduced by more than 90 % to less than 1 %. Applied using the sol-gel dipping process, the coating is characterised by high scratch resistance and resistance to abrasion or chemicals. It is also easy to clean.
The lenses are suitable for high-resolution displays (4K/8K) also with touch function, for HMI (Human Machine Interface) systems and medical or mobile or outdoor applications, to name just a few examples. Customers such as display manufacturers can have the newly introduced protective glass adapted to their requirements. Various processing options are available, from screen printing and lamination to easy-to-clean or anti-fingerprint coating.
Properties Thanks to the Sol-Gel Process
In the sol-gel immersion process developed by Schott, the glass is immersed in various metal oxide solutions, and the metal oxide layers are then baked at 450 to 500 °C. The glass is then heated to a temperature of 450 to 500 °C. Compared to conventional PVD processes such as sputtering or vapor deposition, the coatings are much purer and also mechanically and chemically much more stable.
With uncoated float glass, each side of the glass pane reflects about 4 %, i.e. a total of 8 %. Conturan from Schott, on the other hand, has several metal oxide layers on one or both sides of the float glass sides. This allows the reflection to be reduced by 90 % and is then less than 1 % overall. The glass appears almost invisible.