Knitted wire gaskets
Knitted wire gaskets have been used as EMC gaskets since ages. They consist of metal wires that are knitted and can be formed to several shapes. However, the following shapes have developed to a sort of standard:
Generally all available metal wires can be knitted. Over the time the following wires became standard in the industry:
Knitted wire material can also be supplied as flat band material, which in most cases is used to wrap cables. This flat band material is wrapped over the cables by overlapping each layer. Standard thickness is approximately 0,5 mm. Standard widths are available from 10 to 300 mm.
Due to flexible manufacturing processes all requested dimensions can be realized. Dimensions shown just give a picture of what is possible to manufacture.
All metal mesh gaskets are normally very hard and recommended for single use only.
If the application requires higher gasket elasticity a gasket with an elastomer core should be chosen. Those gaskets consist of an elastomer core that is knitted over with metal wire. Two layers are standard, however, it is also possible to use one layer or more layers.
A protection against environmental influences, such as dust and circulating air, is given. A protection against water (spraying water etc.) is not possible. If the application requires a resistance against dropping or spraying water then a so-called combi gasket should be chosen. These gaskets consist of an non conductive elastomer with PSA backing and knitted wire gasket that is mounted alongside the edge of the elastomer. The knitted wire can be a full metal mesh gasket as well as a knitted wire over elastomer gasket.
To prevent galvanic corrosion engineers should take notice of the electrochemical potential of the wire in combination to the metal used for the chassis, enclosure etc.
Standard shapes of knitted wire over elastomer gaskets are:
- round profiles
- hollow round profiles
- rectangular profiles
- round core with fin
- double round core with fin
In some cases it is necessary to use a very soft gasket. This can be realized by knitting just one layer of a very fine metal wire over a PU-foam.
As an option a non conductive PSA can be applied to the gaskets. It should only be seen as a support during the mounting of the gasket.