soft emi/rfi gasketing
For years, NEDC has supplied low durometer gasketing materials to customers. One product that I realized has been under-utilized the last few years is “low durometer EMI Gasketing”. On this website, we are making a large push to show we are a gasket manufacturer who sells A LOT OF EMI GASKETS. All types. In this blog, we discuss SOFT, SOFTER, and SOFTEST EMI Gasketing!
What counts as a “Low Durometer” EMI/RFI Material?
First thing to note, EMI gaskets are inherently high durometer components. Why is this? Well, these materials are filled with metal particles such as silver-aluminum, pure silver, silver-copper, and nickel-copper. These metal particulates are naturally hard. These particles reinforce the elastomer, but they also make it harder & brittle. This raises the durometer of the material. For this reason, it’s a particular challenge to make a soft EMI/RFI gasketing material.
Why “Low Durometer EMI/RFI Gasket?”
Sometimes customers get in between a rock, and hard place, (pun intended) where they need something soft, but also need material that is compressible with little closing force (reminder, most EMI gaskets should not be compressed more than 20% to maintain the integrity of the elastomers structure, along with the electrical conductivity itself). When a design is finished, they may realize there suddenly isn’t room for additional screw/bolt holes, and they need the EMI shielding to compress easily. Some EMI/RFI gaskets that are filled with silver, or other precious metals require significant pressure (100-300 psi to compress properly). In this case, they need a low durometer EMI/RFI gasket.
electrical enclosure, emi/rfi gasket
electrical enclosure, emi/rfi gasket
Availiability of Soft EMI/RFI Gaskets
Nickel Graphite, 30A Durometer- Great for overall economic and Performance- Available through many manufacturers, SSP (Speciality Silicone Products), SAS Industries
Silver Aluminum, 45A Durometer- Great for high level performance, SAS Industries, SSP (Speciality Silicone Products)
Silver Copper, 40A Durometer- Great EMI performance, Cho-Seal 1270
Pure Silver, Type J for MIL-DTL-83528 (45A durometer). In fairness, I’ve seen MIL-DTL-83528 Type J once in 10 years of working here.
Is there a Softer EMI Gasket?
There are softer EMI/RFI Gasketing materials available. We discuss this in our EMI/RFI Gasketing/MIL-DTL-83528 page. There is:
-Silicone Sponge with embedded Oriented Wire
-Conductive Foam Options such as Condux, EcoFoam™ or Schlegel Gasketing
-Combination Gaskets (this is wire glued onto silicone sponge, neoprene sponge, or fluorosilicone sponge)
-Another strategy is to utilize a hollow material such as a bulb extrusion to allow for super compressibility.
More Information
NEDC manufactures low durometer EMI/RFI Gasketing materials into custom die-cut, and waterjet cut gaskets. In addition, NEDC can add electrically conductive tape onto gasketing materials. For more information on EMI/RFI Gasketing materials, please contact sales@nedc.com.