Have you ever got cranky when you found the push button on the oven does not work, while you are in the middle of cooking? Yes, it sounds quite frustrating. Our life is full of this kind of interface panels. And they have been serving a wide range of industries to meet the customer’s unique needs. We call this control panel as a membrane switch, and custom graphic overlay is the main part of it.
First of all, what is a graphic overlay?
The graphic overlay is the top layer of a membrane switch. It is a flexible piece of plastic with printed image, display window and embossed keys on it. With different graphic overlays, we can divide the membrane switches into two types. One is the membrane switch panel, also known as the non tactile membrane switch. And another type is membrane keypad, known as the tactile membrane switch. Screen printed overlays are assembled with text display windows and key functions. They connect the users and the devices together with great user experience. Besides, it provides good protection for the internal units from exposed.
As a user interface, the control panel overlays can show the user how to interact with the devices. The designer customizes graphic overlays first before production. There are many factors to consider: particular inks, well-designed elements, and featured images. With infinite options, the designer can give the overlay an attractive look. Any desired shapes and sizes are possible too. There two kinds of cutting processes during production, die cut and laser cut. Die cut is for general use. But laser cutting is better for high precision purposes. Professional engineers will decide accordingly. In a word, custom overlays can impress the end-users by unique graphic design in many ways.
Then, why material is important for high quality graphic overlay?
It makes the graphic overlays more user-friendly.
As an interface panel, the user interface needs to be clear and clean. Material with good clarity can help LCD display windows to look more pleasant. Good transparency allows the communications and commands sent to the user clearly. It improves the usability of the control panel overlays.
It makes the graphic overlay and control panels more durable.
All the surface printing buttons will be pushed for over thousands of times during usage. Each time you do it, you give the button some stress. Then after you release the pressure, the button needs to go back exactly where it is. This requires the overlay materials have a high Modulus of Elasticity. Or then, the overlay would develop some undesirable deformation due to the stress. But, elasticity can’t be too high either. Or else, the button is too stiff to press. And only material with high elasticity and good flexibility can make this happen.
Meanwhile, in some cases, membrane switches get exposure to rough environments. For example, humidity can lead to irreversible degradation. Then the lifespan of the digitally printed membrane will shorten. The extreme outdoor temperature could also be quite a threat. In a desert or an icy place, the climate would have side effects on overlays too. Chemicals, solvents or salty water could cause corrosion. But as long as we choose the right material, the overlay can give all the membrane parts the finest protection.
It makes the custom graphic overlays look more desirable.
With the right material, presenting an endless charming look is possible. Thanks to industry technology, there are infinite overlay printing inks to choose from. You can also select the way to print your graphics, screen printed or digitally printed. With the screen print, you can get a great color matching. It has good consistency, so screen print is often used for large-scale production. But digital printing is more suitable for flexible design while sampling. Of course, unlimited color choices are possible for both print. Also, you can have distinct finishes with different materials. For example, you can have embossing, debossing, matte, velvet or gloss. Some finish can help to reduce fingerprints and scratches for indoor use. And some finish is good for the clear display windows, giving countless varied looks. The designer customizes graphic overlays to make overlays look more pleasing.
Most importantly, how to choose the right graphic overlay materials for different applications?
Though there are a variety of materials, not all can make a high quality graphic overlay. Selecting the right substrate is a critical part of the product design process. So before jumping into any conclusion, you may need to consider the following thing:
What environment would the printed graphic overlay be used? Chemical, solvent or salty water exposure? Outdoor or indoor use?
Where (what equipment) are you going to use it?
How would you like to deliver your brand/company image on the graphic overlays?
Graphic overlay material
Since you’ve already had the general ideas about the printed overlays now. It is time to get detailed facts about the three mainly used materials:
Polyvinyl chloride (PVC)
PVC is a cheap material and costs only half the price of Lexan polycarbonate(PC). It has good chemical resistance, electrical insulation, UV resistance, and flame retardancy. It could offer you an appealing look with a variety of colors for the finish. Yet, PVC is not an eco-friendly graphic overlay material for the environment. Meanwhile, it doesn’t perform well in extreme climates. Because it is cheap. PVC printed graphics are still popular for short-run signs and folding boxes.
Polycarbonate material, known as Lexan polycarbonate, is a tough, crystal clear plastic. And it can offer a variety of outstanding mechanical properties. It has very good abrasion resistance, high flame tolerance, and good insulation properties. Polycarbonate materials can endure harsh climates and barely absorb moisture. Plus, polycarbonate materials are optically
clear. So it is ideal for applications like a window display, giving the overlays a better look. With an affordable price, PC is the perfect choice for graphic overlays. But it needs an extra coat for protection if exposed to the chemicals or solvents. PC tends to be easier to make during production. It means processes like die cutting and embossing are easier.
As well, PC overlay is available with varied surface texture and finish. It can meet customer needs with unique and aesthetic designs. In fact, you can see PC overlays for a wide range of applications.
Polyester is another most common material used for graphic overlays. It is a tougher, more durable plastic than PC. Actually, PET is quite famous for its great durability. Even after 1 million actuation cycles, it does not show any signs of wear. While for PC, it is starting to show wear after the same actuation cycles. Also, PET is well known for superior resistance to harsh environments. It even works well when exposed to many chemicals and solvents. These properties are exactly what medical and army applications need. So Polyester is the best choice for applications like this. But polyester overlay often takes longer to make than PC and it costs higher. So the average lead times will be a bit longer.
Which material are you going to choose, polyvinyl chloride, polycarbonate or polyester? All three types of overlays are available in the market and each has its own advantages. It is important to weigh these pros and cons first before you decide. If you need more help with the graphic overlay material, please contact us to get more help.