Project Description


Contact HuaiSong Industrial to get printed graphic overlay with free design, free quote, or even free sample.

1. Graphic overlay definition

Its materials include a wide variety of elastic polyester film materials, such as PET, PC, and PVC. At first, overlay manufacturers use screen printing technology to integrate graphics, texts, and logos into one. Then, stick the double sides adhesive of different materials on it to make the membrane switches graphic overlays. It has excellent features such as waterproof, dustproof, anti-friction and non-fading. Currently, it’s widely used in the user interface of domestic appliance, communication equipment, instrument, industrial control, and other fields

2. Graphic overlay and control panels types

The printing process of custom graphic overlay includes front printing and reverse printing. Apply them to membrane switches of different materials and types, they can be divided into the flat overlay and raised overlay.

The flat membrane overlay is the simplest panel type, which touch screen is also flat. It mainly uses different PMS colors of text, lines, and color blocks to indicate or distinguish various functional parts. Also, users can choose different overlay materials and double-sided tape according to their own needs. In general, we choose polyesters and polycarbonates as raw materials.

The raised overlay of membrane keyboard is developed on the basis of the flat one. And it’s a kind of relatively beautiful and practical control panel. The process to create graphic panels is based on the ordinary panel. Through a pressing mold, graphic overlay manufacturers heat press it. So, the button portion is slightly raised to form a stereo button. The stereo key can accurately locate the shapes sizes of the key body and improves the recognition speed. What’s more, the below metal domes make the touch of the operator more sensitive. At the same time, it enhances the decorative effect of the appearance of the tactile switch.


graphic overlay definition

3. Requirements for making the custom graphic overlay

Screen print the color ink on the back side of a transparent polymer. After the overlays printing and die cut, it becomes a colored membrane layer. Usually, at the stage of proofing, we digitally print to save cost for customers. But as we all know, there will be a difference between screen print and digital print even with careful color matching. After overlay printing, it comes to laser cut. This process needs mold and we cut panel overlays into shapes sizes we want. And the film layer is part of the membrane switch. Through display windows, it can clearly show the function, color, film type and operating position of membrane switches, and it also protects.

After the design and manufacture of control panel overlays and other switch parts, it comes to the membrane switch assembly. Operators paste the overlay, printed circuit board, and other adhesive layers together. As the cntrol panel of the membrane switch, panel overlays have the decoration and protection function of the appearance of the product. Therefore, the custom graphic overlay used for making membrane panel should have these conditions.

3.1 Good appearance.

The membrane surface for making the graphic overlay is flat and has a uniform gloss. And there are no surface defects such as mechanical damage, scratches, inclusions, and stains.

3.2 Better weather resistance.

As we all know, the panel overlays layer is the surface of the membrane switch exposed to the natural environment. So there should be good performance under certain natural environmental conditions. For example, no deformation, cracking, aging and discoloration.

3.3 Better chemical resistance.

Control panels are likely to touch different chemicals. And it should be resistant to most common chemicals, such as alcohols, ethers, and mineral oils.

3.4 Good dimensional stability.

The high quality membrane keypad graphic overlay is stable. It’s required that the size of the control panel has no change within a certain temperature range. Generally, it ranges from -40℃ to 55℃.

3.5 Resilience requirements.

It’s required that the screen printed membrane layer has a certain weakening performance. At the same time, the elastic deformation is small. Graphic overlay manufacturers can judge it by the percentage of elongation. In general, if the elongation is large, the amount of elastic deformation is also large, and the elastic energy is poor.

According to these requirements, HuaiSong membrane switch manufacturer offers a variety of graphic overlays. In general, they include polycarbonate overlays, polyvinyl chloride panel overlays and polyester, and polyurethane control panels.

graphic overlay manufacturers

4. Comparison of different graphic overlay materials

4.1 PVC overlay.

The PVC overlay is suitable for use under the temperature ranging from -15℃ to 55℃. And the thickness can be 0.125mm to 0.5mm. Under room temperature, PVC overlays are stable to acids, bases, and salts. What’s more, they have good wear resistance, fire resistance, and good electrical insulation. But their heat stability is pretty poor. So, it’s suitable for low-end cheap common signs and control panels.

4.2 PC overlay.

Polycarbonate overlays can be used within the temperature ranging from -60℃ to 120℃. And their thickness is always from 0.1mm to 0.2mm. The surface can be smooth or sandy. Firstly, both of them have high light transmittance, low water absorption, and good dimensional stability. Secondly, they have excellent bending, tensile and compressive strength. Thirdly, they are great in heat resistance, cold resistance, electrical insulation and weather resistance. However, polycarbonate overlays are less resistant to fatigue and are prone to stress cracking. In general, they have the widest application. Of course, they can satisfy most membrane switch panels. Among, the high transmittance of the glossy surface (PC) can meet the requirements of the liquid crystal display windows.

4.3 PET film.

It can be used under the temperature of -30℃ to 120℃ with the thickness of 0.1mm to 0.2mm. After using it to manufacture graphic overlay, membrane switches have good chemical resistance, are insoluble in ordinary organic solvents and not resistant to alkali. What’s more, it has excellent mechanical properties, electrical properties, rigidity, and hardness. And it has the strongest toughness in thermoplastics, low water absorption, excellent wear and rubs resistance and high dimensional stability. Moreover, the tensile strength is comparable to that of aluminum film, which is much higher than PC and PVC.

5. Common graphic overlay

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