Combination gaskets are gaining wide acceptance, and use for EMI shielding and environmental sealing for electronic enclosures. In other words, they provide both a weather seal, and an EMI/RFI gasket. They offer the benefits of having mesh and elastomer essentially within one gasket. This can be convenient for the end-user to be able to have both products in one without doing tiring, or arduous assembly. There are two standard parts in the combination gasket, and then sometimes a third for ease of assembly. There is the elastomer, or the rubber, the mesh for EMI shielding, and the adhesive backing, detailed below:
NEDC offers custom-fabricated EMI gaskets—also known as combination gaskets—that provide both EMI/RFI shielding and environmental sealing in a single, streamlined solution. These gaskets are widely used in electronic enclosures where electromagnetic interference needs to be blocked while maintaining a weather-tight seal.
By integrating a conductive mesh and an elastomeric sealing material, EMI gaskets deliver dual-function protection. This eliminates the need for separate EMI shielding and environmental sealing components—saving time, labor, and assembly effort.
Key Components of EMI Combination Gaskets
1. Elastomer (Environmental Seal)
The elastomer layer in EMI gaskets provides critical environmental sealing, supporting applications requiring NEMA or IP-rated protection. NEDC offers a range of elastomer options, including:
- Silicone sponge
- Solid silicone
- Neoprene sponge
- Fluorosilicone rubber
- Neoprene rubber
These materials comply with relevant standards such as ASTM D6576, ASTM D1056, A-A-59588, MIL-R-25988, and MIL-R-6855. Sponge rubber is ideal for lightweight or low-force compression environments, while solid rubber provides a more rigid seal. To prevent over-compression, NEDC can integrate compression stops—typically made from aluminum finished to MIL-C-5541 1A.
2. EMI Mesh (Conductive Shielding Layer)
The EMI shielding function comes from a conductive metallic mesh embedded in the gasket. This mesh ensures electrical continuity between mating surfaces and helps block EMI/EMP interference effectively.
Common mesh materials include:
- Aluminum alloy 5056 (per AMS-4182)
- Monel QQ-N-281 (per AMS-4730)
- Tin-plated, copper-clad steel (per ASTM B520)
Mesh geometry and elastomer pairing are carefully selected based on the enclosure’s design and shielding needs.
3. PSA Adhesive Backing (Ease of Assembly)
For simplified installation, NEDC can apply a pressure-sensitive adhesive (PSA) backing—typically 3M™ 467MP from the 200MP adhesive family. These acrylic adhesives are popular for their durability, weather resistance, and easy application. In some applications, silicone-based adhesives are also available.
Why Choose NEDC as Your EMI Gasket Supplier?
At NEDC, we specialize in fabricating custom EMI gaskets that meet tight design tolerances, even for challenging electronics or defense-related applications. When needed, we use RTV (Room-Temperature Vulcanizing) methods to securely bond mesh and elastomer layers, enhancing cost efficiency and long-term performance.
Common Configurations Include:
- Fluorosilicone rubber with aluminum mesh
- Silicone rubber with Monel mesh
- Neoprene sponge with tin-plated copper mesh
Whether you’re designing for aerospace, military, telecommunications, or industrial electronics, NEDC delivers EMI gaskets that combine shielding and sealing in one reliable component.
Request a Quote
Contact us at sales@nedc.com to discuss your EMI gasket requirements or to request a custom quote.