Shielding Gaskets and Corrosion

It is a well-established fact that all metals are sensitive to corrosion.  Metal has an intrinsic propensity to react electrically or chemically with its surroundings. As a result, most shielding gaskets are designed to withstand different corrosive environments. There are four general classes of environments that gaskets are designed to withstand.

Class A: Class A environments are considered to be controlled, meaning that temperature and humidity are regulated by human control.  These environments represent habitable exposure and are mostly indoors.

Class B:  Class B environments are considered areas that are uncontrolled, or do not have the ability to regulate heat and humidity by manual manipulation.  Class B environments are also exposed to a humidity level of 100 percent, and experience occasional wetting.  It is common to find a class B environment in an Outdoor warehouse or alternative storage unit

Class C: Class C represents marine environments, which are environments aboard a ship, or within two miles of salt water. Salt from the water exacerbates levels of corrosion.

Class D: Class D represents space conditions, or environments with exposure to a high vacuum, and also high levels of radiation.

EMI Shielding gaskets can be used in any one of the four aforementioned classes. Electromagnetic interference becomes more pronounced as the use of complex computers and technology increases. In every aspect of society, including NASA research to changing channels with a television remote, they will need to be shielded in order to remain operational.

Gaskets are often finished to arrest chemical corrosion and provide shielding from EMI.  Class A, B and C are the only environments that use additional finishes to protect gaskets. Class D, being a space environment, does not experience corrosive agents, and metals are not affected.  Different finishes are appropriate for different classes, so it is important to purchase the right gasket for a specific application.  Gold, platinum, silver and graphite, are popular finishes that protect gaskets from corrosion. In some cases, organic finishes have been used to negate corrosion of EMI shielding gaskets.

If you are interested in learning more about EMI shielding, or EMI gaskets, it is always best to contact a local professional in your area.  Speaking with an expert directly is the best way to ensure that you will be purchasing the right type of gasket for a given application.  Corrosion can ruin an industrial system, so it is import to become knowledgeable about the different class types, and the correct gasket to use in a particular environment.

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