The selection and matching of the right cover glass is an important aspect in developing the perfect HMI for your application. It starts deciding on the right material, continues through the selection of the appropriate colour option through to the desired or required edge and surface machining, such as different hardening processes for increasing the durability. Supporting us in this work are our partners with many years of experience, such as Irlbacher.
A large number of different raw materials are available for the production of cover glasses. A fundamental distinction is made here between soda lime glasses – which are available, for example, as a neutral-coloured white glass, as green-tinted float glass or in body-tinted coloured versions – and aluminosilicate glasses.
A cover glass is characterized on the one hand by the shape of the edge processing. Common options, which can be produced in both matt ground and polished forms, are shown in the following diagram. Certain processing forms call for a specific thickness of glass, consequently not all of the characteristics can be produced for aluminosilicate glasses (see also Processing, screen-printing and stability table).
On the other hand, the surface processing is decisive for the optical and haptic properties of a cover glass. While naturally plain glass surface are desired for certain applications, etched glasses are suitable for input system that have to assume certain requirements for haptic or antireflective properties. A wide range of etching options are available, which are characterized among other factors by the gloss value. The gloss value is a measure of the proportion of reflected light and has to be quoted as a function of the angle; see the following diagram for a definition.
|Sodalime glass||aluminosilicate glass|
|Available thicknesses||2 – 25mm||0,5 – 1,8mm|
|Semi-toughening (TVG) and toughening (ESG)||+++||-|
|Glueing on printed areas||+++||+|
|UV resistance (printing)||+++||-|
|Thermal stability (printing)||+++||+|