From military equipment to consumer electronics, from communication systems used in automobiles to medical devices in hospitals, and from wireless gadgets to satellite communication, all types of electronics and electro-mechanical stuff are susceptible to electromagnetic interference (EMI). Such disturbances can be attributed to the energy emitted by the electrical motors, radio transmitters, and circuitries that make up the cores of these devices. From dangerous health consequences to electronic jamming of military devices, EMI has emerged as a threat that has captured the attention of manufacturers across many sectors. Electronic enclosures are used to keep EMI-prone devices protected against electromagnetic interferences. EMI shielding enclosures for most of today’s applications are made of conductive elastomer products. Composed of dispersed elastomer particles, this solid material has all the right properties that enable it to prevent electromagnetic induction or electromagnetic radiation from interfering with the equipment’s electrical circuits.

Elastomers versus Metal Shielding Products

Although for years, metal sheets remained the material of choice for engineers for making custom shielding solutions, elastomers are fast outpacing them in popularity. Why? Shielding solutions made of elastomer materials enjoy a few advantages over their metal counterparts. While shielding enclosures made of sheets of copper, aluminum, and steel are strong and sturdy, they tend to deform easily under the high pressure that’s used to seal the enclosure properly. And once deformed, it is not possible to bring these metal enclosures back to their original shapes. As such, they become incapable of containing electronic interference. Moreover, some metals rust faster than other materials which leave them incapable of providing proper shielding. This explains the surge in the demands of elastomer shielding products.

Evolution of Elastomer EMI Shields

In response to an unprecedented rise in the use of electronics, the EMI shielding manufacturers have introduced many innovations in the creation of elastomer materials. For example, the practice of making elastomer shields with coatings made of metallic inks is on the rise. Also, silicone elastomers combining metal or metal-coated particles are widely used for shielding as these substances combine two unique features – the long-lasting qualities of silicone rubber and the electrical properties of metals.

Particle-filled silicone elastomer compounds have excellent electrical conductive properties, offer an excellent environmental sealing, and ensure a high level of EMI shielding. However, the previous generations of particle-filled silicones had some drawbacks such as hardness and poor compressibility. Also, they were not very cost-effective, thanks to their use of expensive conductive fillers such as silver-plated copper and aluminum. To address these loopholes, newer particles are used as filler materials in the new-age silicone elastomers. These materials are designed to meet the highest level of shielding effectiveness requirements like MIL-DTL-83528. And in the process, they act as a benchmark for the other demanding applications.

The newer particle-filled silicones are characterized by the presence of lower-durometer compounds. The use of these substances renders them a high tear-resistance capacity so that they can avoid the related issues that commonly occur during gasket fabrication. Sometimes, lower-durometer, particle-filled silicones are coated with an inner layer of conductive fabric or mesh for further resistance against tearing. Unlike their older versions with lower tear strength, these newer silicone elastomers can provide a thinner, and therefore, lighter EMI shielding for a variety of applications.

Author Bio:

Simon Hopes is a renowned author and social media enthusiast. Electrically conductive elastomer products are ideal for both commercial and military applications. All the top EMI shielding companies offer elastomer shields to meet a wide variety of applications. In situations where the basic geometry of the enclosure is already specified, for example, in the case of the military EMI shielding applications, there is not much scope of customization. In such cases, three factors, namely, the closure force, the percentage of landfill, and compression/deflection have to be considered for designing elastomer enclosures.