Are your Membrane Switches on the right material?
In our everyday support of various market sectors, we are often asked about best practices to meet industry-specific standards. A common subject that crops up is, “Are our graphic overlays and membrane switches on the right material?” This is a critical question that needs to be answered at the very beginning of every new project. Some customers already know the right materials to use, others may select a substrate based on previous results. Regardless of previous scenarios, it is prudent to discuss each project with fresh eyes. Then build a plan that is product suitable and agreed upon by all parties.
The typical construction of Membrane Switches uses polyester film for the graphic overlay in a user interface. It is the industry recognised substrate due to its outstanding performance. It especially has the ability to withstand a wide variety of environments and the high stresses from repetitive use. Other materials such as polycarbonate generally do not have the same properties and may embrittle and crack over time even though they still have their own specific durability benefits.
Supporting OEMs from a wide range of market sectors, RH offers support and advice during an initial project review, where the concept CAD design is discussed including performance and environmental parameters. As you can imagine, a finished membrane switch has to be fit for purpose, be it a medical product, a control panel for the Military or any industry.
In this design briefing, RH will review all considerations of the operational parameters of a membrane keypad. This review may identify some changes in the construction or materials used. For example, a hard-coated polycarbonate substrate that works wonderfully as a durable control panel may struggle with embossing or some chemicals. Here is where our Engineering Department can really assist your product designers. We can translate your amazing ideas into practical solutions in manufacturing.
Polyester is generally the recommended substrate
Polyester is the most commonly recommended graphic overlay substrate for membrane switch construction. It is available in a range of textures and finishes, as well as variants suitable for specific applications including:
- Fine texture
- UV Stabilised
- Soft Touch
Once the concept design is fully discussed, and the specific polyester specified, RH offers advice regarding:
- Display windows
- Cosmetic finishes such as selective texturing and resin doming etc.
- Special ink effects
Remember if the material isn’t right then the product will simply not perform to the desired level. Selecting a material that has the right durability is vitally important, but not the only consideration. The printed inks need to bind to the material and may need to be flexible. Does the material have a UV rating to protect against fading? Can the top layer create an effective moisture lock? Does the material thickness allow for proper actuations of internal metal domes? The permutations by industry and function are vast, so let us help!
Having completed the design review RH is also able to offer a prototyping service to prove the design prior to moving into full production. As a manufacturer, this can be done in our own factory here in the UK, or via our partners in China. We are also able to offer life testing of your membrane switch operation.
Below we have created a downloadable document that might give you further insight into the types of useful materials and their individual features and benefits.