Conductive rubber in any form helps defense agencies and commercial electronic product industries meet environmental and EMI/RFI emissions requirements, which is crucial to protecting the integrity of susceptible applications like HVAC systems, power and signal panels, door and panel hinges, latches and brackets, floor drains, structure seams and ISO intermodal, container brackets, antenna mounts, cable and connector panels, and structural bolts.
Conductive rubber is designed to meet shielding requirements in a variety of indoor and outdoor environments including:
Conductive rubber comes in a variety of material types. There are three that are most commonly used: Conductive Silicone, Multicon, and Radthin. The type of rubber depends on the specific application.
Conductive Silicone (Conductive Elastomer)
The base material in Conductive Elastomer is comprised of silicone or flurosilicone compounds. It can be die-cut to meet various configurations. The advantage over other materials is that it can be configured in a variety of extruded profiles and die or flash cut into unlimited shapes and sizes. Conductive Silicone provides high electrical conductivity, broadband shielding, and dust/moisture sealing (see IP table below). This material is designed to provide reliable and cost-effective shielding for a wide range of EMI applications.
Multicon, is a combination of silicone and conductive wire paths. It is available in a wide range of thicknesses and widths and can be die or flash cut. Available in solid or sponge silicone, it’s offered with either Monel or aluminum wires in several different hardnesses. Multicon is constructed in such a way that when pressure is applied to the gasket, hundreds of sharp wire ends become exposed making electrical contact with mounting surfaces.
Radthin is made of a 24 mesh aluminum alloy wire cloth impregnated with 50 durometer neoprene or silicone rubber compound. It’s not as widely used as Multicon or Conductive Elastomer, but it is often used for ultra-thin gaskets that can withstand a wide-range of temperatures is needed. Radthin can also be die-cut for custom applications.
In order to design the appropriate shielding option to meet shielding and environmental requirements, the Ingress Protection (IP) rating needs to be identified, which is determined by the environment in which it will be used.
IP ratings classify the degrees of protection against the ingress (intrusion) of a solid or liquid object in an electrical enclosure. IP ratings are normally two numbers. The first number relates to protection against solid objects (i.e. dust, dirt, sand), and the second number denotes protection against liquids (i.e. water). The lower the IP number, the lower the requirement.
First Number Indicators
|0||No special protection.|
|1||Protection from a large part of the body such as a hand from solid objects greater than 50 mm. in diameter (no protection from deliberate access).|
|2||Protection against fingers and other objects not greater than 80 mm in length and 12 mm. in diameter.|
|3||Protection from entry by tools, wires, etc. with a thickness of more than 2.5 mm. in diameter.|
|4||Protection from entry by solid objects with a thickness diameter or thickness greater than 1.0 mm.|
|5||Protection from dust (no harmful deposit) that would interfere with the equipment operation.|
|6||Totally protected against dust.|
Second Number Definitions
|0||No special protection.|
|1||Protection from vertically falling water drops or condensation.|
|2||Protection from water sprayed at an angle up to 15 degrees from vertical (light rain in wind).|
|3||Protection from sprayed water at an angle up to 60 degrees from vertical (heavy rainstorm).|
|4||Protection from sprayed water in all directions.|
|5||Low pressure water projected from a nozzle (residential hose).|
|6||High pressure, powerful jets of water.|
|7||Temporary immersion protection (15 cm. to 1 m.)|
|8||Protection against complete, continuous submersion in water (submarine).|
One of the most common equipment IP ratings in the electronics market is IP67. It means the product is 100% protected against dust and moisture and has been tested to work for at least 30 minutes while under 1m of water with no harmful effects. Conductive Silicone is one the best materials for sealing to IP67. Other products like EMI knitted wire mesh gaskets, strip gaskets, Multicon gaskets, cut, and O-ring gaskets have varying degrees of IP protection materials and offer their own unique solutions for the mitigation of electromagnetic interference and radio frequency waves.
We serve the overall electronics industry and look forward to working with you on your next shielding requirement.