Silicone Keypad for Truck Audio
Backlight (laser etching) Keypad.
1). General purpose silicone in translucent, milky for molding the rubber blank.
2). Spray painting in multi-color layers(basic, white/black).
3). Laser etching for all graphics for a blacklight effect.
4). Light box inspection in a drak room for the graphics backlight and the keypad light leak.
5). Surface coating for protection.
a). Silicone matte (SM) coating for a comfortable touch feeling.
b). PU matte coating for a good worn/abrasion proof(RCA Tester).
Above 400 continual cycles with 175grams load guaranteed by RCA tester.
c). Adds UV-proof material on the above a) and b) to stop the white graphic becoming yellowish for the outdoor environment(Marine,outdoor, military...).
Highlights:
The following silicones are not suitable for a backlight keypad.
a). Fluorosilicone(FSR), due to the standard FSR color is light yellow or white( There is a transparent FSR on market, but the price is sky).
b). Flame retardant silicone, especially for UL94-V0 grade silicone, due to the color is off-white.
To improve the key cycle life, a high tear silicone can be added into the molding.