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Graphic overlays are made of two primary materials:
Polyester
Polyester is slightly more expensive than polycarbonate. However, we will use polyester plastic in applications like embossed keypads and graphically enhanced membrane switches because it has a long flex life.
Polyester is resilient against acids and chemicals, so the electronic devices used in medical and microbiology labs have polyester graphic overlays.
They are suitable for high tensile strength and dimensional stability applications. The function at full temperature and humidity ranges
Polycarbonate
Polycarbonate is cheaper than polyester. It is used in consoles, user interface circuits consisting of complex keys, hardwearing, and in harsh outdoor environments.
It is resilient against seawater and can be used as a graphics overlay in maritime electronics.
They have better optical clarity. Tight against heat, abrasion, and stains. They have high impact resistance and are durable.
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Design Details |
Polyester |
Polycarbonate |
|
Chemical Resistance |
Broad |
Limited |
|
Scratch Resistance |
Better |
Good |
|
Actuation life |
>1 million |
Up to 200K |
|
Emboss-ability |
Good |
Good |
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Ink receptivity |
Good |
Good |
|
Flexibility |
Good |
Better |
|
Fold endurance |
Better |
Good |
|
Material thickness |
Up to 0.254 mm |
Up to 1.52 mm |
|
Hygroscopic resistance |
Very good |
Fair |
|
|
|
|
Screen Printing
The method used to imprint the graphics on the substrate is screen printing. In this, the mesh transfers ink onto the substrate when the blade is moved across the screen.
This will fill the open parts of the stencil with ink while the clocked elements are not supplied.
The mesh is made of nylon (synthetic polymer) with a smaller/more exceptional aperture for more resolution of details of imprinted graphics.
This is the mesh with excellent material squeezed to spread the ink—the more beautiful the resolution, the better.
Film positive with a design pressed next to the screen in a vacuum and exposed with solid lights.
The area is exposed to film and clear of emulsion, allowing ink to pass through the garment.
Graphic Overlays Applications
They are widely used in many devices, panels, consoles, keyboards, and interfaces.
- Medical Devices
- Equipment panels
- Control Panels
- ATMs
- Remote access device
- Temperature controller, Servo control panels
- Various tech instruments like oscilloscopes, function generators, power supplies for label printing, and graphic overlays
Custom Graphics overlay
There is a possibility that the customer demands the manufacturer to design a customized graphic overlay according to his requirements. This is done quickly.
A thermal transfer process is used in which a colored resin is merged onto the rear side of durable ten mil polycarbonate / Lexan film.
The resistance to scratch and chemicals is tremendous. When printed, a sticker or adhesive layer (Peel and Stick) is added, and the graphics layout is cut according to customer requirements.
The resultant is a product similar to screen printing, while the whole process just took a fraction of the time and much less cost. This installed screen printing eliminates the need for tooling costs and time delays associated with conventional screen printing.
