Parker Chomerics EMI Shielding Wire Mesh Gaskets

Parker Chomerics COMBO STRIP® Metal Mesh Gasketing with Elastomer Weather Seal

Parker Chomerics COMBO STRIP gaskets are a resilient, highly conductive sealing solution consisting of knitted wire mesh integrated with an elastomer weather seal.

COMBO STRIP® Advantages:

• Various standard and custom material and cross sectional geometry choices allow for application specific performance to be attained.
• Application specific design offerings ensure improved gasket performance, thereby reducing costs associated with seal replacement and application rework.
• High metal content ensures very good electrical performance for the seal.
• High metal content results in a gasketing solution that can meet demanding requirements for both EMI shielding and current carrying, making this a solution that can be applied to a broader range of applications as compared to other electrically conductive gasketing options.
• Knit construction provides durable, yet light-weight gasket performance.
• Light-weight gasketing is an optimal solution for applications with weight or fuel savings requirements; parameters that are typically prevalent in the military and aerospace markets.
• Various features available to eliminate wire mesh fraying, thereby eliminating foreign object debris concerns.
• Elimination of foreign object debris ensures costly application reworks due to electrical shorting can be avoided.
• Mesh affixation methods to the elastomer can be attained via bonding or overmolding, allowing for various degrees of overall sealdurability and precision.
• Elastomer overmolding onto mesh ensures improved durability and tolerance schemes for applications requiring extremely high performance, whereas bonded options provide a more economic.

Parker Chomerics COMBO STRIP Selection Guide

Application Information - 5 Design Variables

COMBO STRIP gaskets are used to provide either EMI shielding, EMP resistance or lightning strike performance in unison with weather sealing capabilities for a variety of Military and Commercial applications. Five design variables should be considered when making a COMBO STRIP product selection. Each should be evaluated prior to gasket design to ensure optimal performance.

1. Wire Mesh
   
   Numerous design criteria should be evaluated when selecting a wire mesh. The most critical of these criteria include galvanic compatibility, electrical performance, overall gasket durability and temperature range requirements.
2. Elastomer
   
   Three specific design parameters are the most important variables to take into consideration when evaluating elastomer choices. These criteria are fluid exposure, temperature requirements and necessary compression characteristics of the material. Generally, solid elastomers are used in conjuncture with cast or machined surfaces due to their larger force requirements for deflection. Sponge offerings have less force requirements for deflection and are therefore typically used in conjuncture with sheet metal enclosures.
3. Geometric Profile
   
   Geometric profile selection should be decided upon in parallel with elastomer material selection. Various design criteria should be evaluated. These criteria include, but are not limited to, gasket deflection percentage, necessary compression characteristics of the material, application load available for gasket deflection and planned gasket affixation method. To provide effective performance, it is recommended that gaskets be deflected 30 +/- 15% of their nominal height.
4. Foreign Object Debris
   
   For applications with foreign object debris (FOD) requirements, Parker Chomerics provides terminated custom lengths with non-fraying ends by utilizing a variety of encapsulants including fluorosilicone, silicone, acrylic and urethane. Possible fluid exposures should be taken into consideration when choosing an encapsulant material to ensure long-term performance.
5. Miscellaneous Typical fabricated gasket form factors for nonovermolded gaskets consist of corner splices utilizing RTV. For applications where a more robust solution is necessary, die-cutting sheeted elastomer material and then bonding the mesh is recommended. For applications in which over-compression at the bolt holes may occur, this can be avoided by bonding washer-type metal compression stops within the elastomer. Compression stop thickness should be targeted at the height which gives the finished gasket a nominal 30% deflection. For applications where a weather seal is not required, please refer to the MESH STRIP gasket data sheets.