Jul, 26 2016

Defense Electronics Features SSP Particle-Filled Silicones



Defense Electronics Features SSP Particle-Filled Silicones

Particle-filled silicones from Specialty Silicone Products (SSP) are the subject of a feature article in Defense Electronics, a leading resource for design and development engineers who work for the U.S. military, homeland security, other government agencies, and defense contractors. In Particle-Filled Silicones Satisfy EMI Shielding Needs, SSP Product Manager Dominic J. Testo explains how SSP’s shielding silicones combine high levels of EMI shielding with ease-of-use, an important consideration for gasket fabricators.

The causes of electromagnetic interference (EMI) are numerous – and so are EMI shielding products. Historically, engineers incorporated metal sheets into their electronic designs. Sheet metal can deform under the mechanical pressure that’s required for sealing, however, and a loss of electrical conductivity and shielding effectiveness (SE) may result. Metal screens, metal wires, and metal foams offer alternatives, Defense Electronics explains, but particle-filled silicones provide distinct advantages. 

Understanding Particle-Filled Silicones

Silicones provide thermal stability over a wide temperature range and resist the passage of water, ozone, and ultraviolet (UV) light. These synthetic elastomers can form tight environmental seals, and retain their elastic properties even after long periods of compressive stress. When filled with metal or metal-coated particles, silicones deliver consistent electrical conductivity and reliable EMI shielding. Particle-filled silicones can also meet MIL-DTL-83528 requirements for conductive elastomeric shielding gaskets. 

As SSP’s Dominic J. Testo explains in Defense Electronics, particle-filled silicones also support gasket fabrication. The company’s SpecShield™ family of EMI elastomers come in a range of durometers and are supplied as continuous rolls, conductive sheets, extrusions, and ready-to-mold compounds. SpecShield™ elastomers also include ArmourRFI™ shielding silicones with conductive fabric reinforcements. For applications that also require fuel chemical resistance, particle-filled fluorosilicones are available.   

Meeting Multiple Military Requirements

SSP’s article in Defense Electronics includes the results of independent testing on two SSP materials. SSP-2368-65 is a shielding silicone that’s filled with silver-plated aluminum particles. SSP-502-40 is an EMI elastomer filled with nickel-coated graphite particles. The article in Defense Electronics also describes a case study from Stockwell Elastomerics, a leading fabricator of EMI shielding gaskets.

When a defense contractor needed a sealing and shielding solution for military touchscreens, Stockwell chose a nickel-graphite product from SSP. The gasket fabricator then applied its expertise in molding, water jet cutting, and adhesive lamination. Ultimately, Stockwell met a tight engineering-build deadline while minimizing material waste and cutting thin-wall gaskets without pulling or tearing.

Learn More. Ask the Author.

Do you have questions about particle-filled silicones EMI shielding? For more information, email Dominic J. Testo of Specialty Silicone Products (SSP).