Membrane switches are an essential user interface critical in every product design. It’s a series of layers and components, and each of these parts has specific functions. The number and types of layers differ, and making the right combination determines its functionality. Overall, the components work together to create an electrical connection.
One of the most critical layers of a membrane switch is the graphics overlay, which is also known as the membrane switch overlay. It’s the outermost layer of a membrane switch, acting as the main point of interaction between the switch and its user.
Apart from that, it serves as the visual representation of the final product. It also has several layers, which you’ll understand as you read this blog.
The Different Layers of a Graphic Overlay
A graphic overlay has several components, each with a purpose that makes a membrane switch effective. The components or layers of a graphic overlay are as follows:
Base material
A graphic overlay can be made from different materials, but polycarbonate and polyester are two common materials today.
- Polyester: Widely and popularly known as polyethylene terephthalate (PET), polyester is a transparent, flexible, and chemical-resistant material. Due to its properties, polyester has become the best option for long-term use. It’s also ideal for switches with tactile feedback since it resists puncturing and tearing.
- Polycarbonate: This material is perfect for flame-retarding and abrasion-resistance applications. At the same time, it’s easier to process and is more economical compared to polyester. It’s also processed quickly without shrinking or warping.
There are other materials available for creating graphic overlays. Some examples are acrylic, PVC, and vinyl. Choosing the best one that suits the product’s needs is crucial. You can also select its finish and texture for optimal results and abrasion resistance.
Graphics
The top and most visible layer of a membrane switch is the graphics. You can use an inkjet printer, but it still depends on the design requirements and what you want the product to look like. The graphics are usually made out of special inks resistant to chemicals.
For polyester and polycarbonate, subsurface printing is used to print these inks. Subsurface or second-surface printing is when a mirrored graphic is printed on a transparent material. Once the material is flipped over, the design is under it to protect against harsh elements.
Apart from subsurface printing, you can also opt for front-side printing. It’s when the print is laid on top of the material. It creates selective textures and translucent windows.
Adhesive
The final layer of a graphic overlay is the adhesive. The thickness and strength of the adhesive will depend on what type you apply your graphic to. Plus, the cut of the bond is essential since it ensures that the switch components can move in a particular manner.
The type of adhesive commonly used is acrylic since it offers many benefits. Some of these are as follows:
- Resistant to humidity: No reduced bonding is shown, even in high temperatures.
- Withstanding UV light: Membrane switches that use acrylic adhesives can withstand different climatic conditions, such as UV rays.
- Water resistant: Water doesn’t affect the bond strength of acrylic adhesives.
- Resistant to chemicals: Chemicals, such as oil, alkalis, and mild acids, don’t impact acrylics.
- Heat resistant: Short-period exposure to high temperatures doesn’t affect the bond of acrylics. But for long-period exposure, it can resist temperatures up to 300 °F.
Graphic Overlays are the Key to a Great User Experience
Knowing what a graphic overlay is made of allows you to create a user-friendly product. It should withstand different elements and still provide a great user experience. It’s important to remember that the graphic design used for graphic overlays should also consider its environment. The colors, texture, portability, and other factors must also be considered.
Consider the graphic overlay if you’re contemplating creating a custom membrane switch. For more questions and concerns, contact us today or request information, and we can design and develop a membrane switch that exceeds your expectations.