All electrical products contain some kind of interface, including buttons, toggles, dials and joysticks, but without a graphic or written depiction of what each interactive part does, a consumer will find the product difficult to use. This is where graphic overlays come into play. There are four main functions of a graphic overlay: to promote safety and clear instructions, to prevent moisture and debris in the unit, to prolong switch actuation life, and to promote brand images.
Promote Safety and Clear Instructions
The main purpose of a graphic overlay is visual representation of an interface panel or switch which allows end users to interact correctly with the product. For example, you can show your customer easily where the emergency stop button is by surrounding it in yellow and adding the words “EMERGENCY STOP” above it.
It is very important that your graphic overlay defines all interfaces clearly and accurately for safety reasons and to give the best end-user experience possible. Keep in mind that some graphic overlays may need to follow compliance regulations, such as those found in NFPA 79: Electrical Standard for Industrial Machinery.
In addition to visual interfacing, other uses for graphic overlays include preventing moisture and debris in the unit, prolonging switch actuation life, and promoting brand images.
Prevent Moisture and Debris in Unit
A graphic overlay is made of a combination of a film (usually polycarb or polyester) and an adhesive that, when combined, create a barrier between the outside elements and housing, further protecting the electrical components underneath.
In order to create the best seal possible, make sure that all cut-outs for switches, joysticks, and dials are sized correctly with accurate tolerances. Too small of a cut-out size means that the overlay and the parts will not fit together, and housing for the switches may cause the overlay to bubble, ripple, or even delaminate. Too large of a cut-out size opens up the possibility of moisture or dust entering the unit and causing the electric or mechanical components to possibly lose functionality or fail.
Prolong Switch Actuation Life
Buttons on a graphic overlay, whether embossed or not, have membrane or mechanical switches underneath them inside the unit. While it would be possible for some of these switches to be open to the outside, their lifespan can be increased substantially by covering them with an overlay. The overlay prevents switches from being accidentally pressed, broken off, or pressed in too far.