Rubber Keypad Terminology
Actuation Force:
The force required to collapse the web of a rubber keypad in conjunction with polydome, metal dome, mechanical switch or rubber only.
Air Channel:
Air path(s) on the bottom of rubber keypads that allows for air passage when rubber is depressed.
Alignment Hole:
Through hole in rubber keypad that is used to position keypad in enclosure.
Base Matte:
Silicone sheet material that joins all keys on a rubber keypad. Also known as mat.
Bezel:
The faceplate or cover, typically plastic or metal, used to secure a keypad to a printed circuit board or switch.
Bosses:
Small posts used for positive alignment of rubber keypad in bezels or assemblies.
Compression Set:
The measurement of a material's ability to recover its original size and shape after compression under prescribed conditions.
Conductive Rubber:
Silicone keypad impregnated/coated with conductive material.
Color Matching:
The visual and electronic analysis of a mixed silicone rubber material compared to a supplied color sample.
Diaphragm / Web:
The thin hinged area that permits a rubber key to flex.
Durometer:
A measurement range of hardness for silicone rubber.
Key Height:
The measured distance from the bottom of a keypad (base matte) to the top surface of a key.
Legend:
Printed graphic (symbol, letter or number) on the top of the rubber surface.
Life:
The number of actuations realized before the rubber diaphragm/web ruptures.
Reversed-Out Graphics:
Graphics that allow rubber color or masking color to be seen through top surface printing on keypad.
Positive-Image Graphics:
Single or multi-color printing on top of key surface.
Snap Ratio (A-C)/A:
See Tactile Response Graph
Stroke / Travel:
Distance from the contact surface of a rubber part to a surface.
Swell:
The increase in volume of rubber when in contact with petrochemicals for a determined period.
Tactile Feel:
The response of rubber while depressing. For tactile rubber keypads, it is a critical function of the diaphragm web geometry.
Tear Strength:
The tear strength is a measure of the resistance of rubber to tear forces. The tear strength is calculated by dividing the maximum force load by the thickness of the rubber.
Wear or Abrasion Resistance:
The resistance of a particular ink or coating to manual wearing. The testing process is usually a Norman tester with the number of cycles legends can perform before wear is noticeable.