At NEDC, our main business is die cutting different materials. One material we see often enough is oriented wire lodged in silicone or fluorosilicone rubber material. These materials are referred to as oriented wire gaskets. These wires are oriented 90 degrees against the direction of the elastomer. These composite gasket materials are popular across the industry for a combination of weather sealing, and EMI Shielding.
These materials are manufactured from giant blocks of material. However, they are sliced down into sheet/strip form to be then converted into custom gasket shapes through die cutting or waterjet cutting.
The Compositions of the Gaskets:
These materials have two components:
Monel Wire per QQ-N-281, AMS-4730 (.0045’’ Dia wire)
Aluminum Alloy 5056 per AMS-4182 (.005’’ Dia wire)
SnPhBronze Alloy 30 per ASTM B105 (.0045’’ Dia wire)
Different wire alloy options allow for the designer to choose an option that will fit their galvanic compatibility needs. These wires are cured into place during the manufacturing process, so dislodging will not occur.
Closed Cell Silicone Sponge per AMS-3195 Medium Density, (Color Grey)
Silicone Rubber per A-A-59588 Class 2B Grade 40, (Color Grey)
Silicone Rubber per A-A-59588 Class 3A Grade 30, (Color Grey)
Fluorosilicone Rubber per MIL-R-25988 Type II Class 1 Grade 40, (Color Blue)
Thicknesses of these materials range from .032’’ to .188’’ in thickness.
Different elastomer options allow the designer to pick a gasketing material that will fit their needs. In addition, different softness options allow for a wide allowance of ways to compress the gasket. In addition, solid rubber such as Grade 3A Grade 30 is more durable.
Oftentimes, customers utilize what is called “partitioned wire” meaning the wire is only present in a certain part of the gasket. Usually this is presented as half the width of the gasket. The portion of the gasket that contains the wire allows for an EMI seal while the remainder of the gasket serves as an environmental seal.
Notes on PSA (Pressure Sensitive Adhesive)
Customers will often think that because this gasket is utilized as an EMI Seal, that an electrically conductive tape is required. However, because the wires will pierce unsupported adhesive, it can create electrical contact through the adhesive itself, similar to an embossed surface. In addition, the elimination of conductive adhesive options further reduces concerns on galvanic compatibility potential concerns.
NEDC die cuts or otherwise converts oriented wire gaskets into finished gasket shaped components. For more information on oriented wire rubber materials, or you believe you have an application that could utilize it please contact firstname.lastname@example.org.