Because of their many applications, membrane switches need to withstand a range of environments. Dirt and grime, moisture, and chemical cleaners can all take their toll.
By using polyester materials for the top layer graphic overlay, you can maximize environmental durability and chemical resistance. However, polyester’s dimensional stability also makes it difficult to form, so visual embellishments like raised buttons and embossing can be difficult to execute.
Polycarbonate is easier to work with, but it is not as durable as polyester, so instead many manufacturers are opting for blended materials. These combinations of polyester and polycarbonate can help engineers address visual and environmental requirements across a range of dimensions.
Depending on the application, membrane switches can be exposed to a range of adverse weather conditions. In these situations, the ability to seal and protect internal components from moisture becomes critical.
A variety of construction options are available (3M HV tapes, custom-designed solid gaskets, etc.) that allow engineers to design interface assemblies that meet a range of different environmental standards. For instance, membrane switches can be developed to meet IP sealing standards, to handle submersion testing applications, or to support NEMA closure requirements.