POLA (Orientated Wire in Silicone)
POLA (Orientated Wire in Silicone) is available in either solid silicone and fluorosilicone or silicone sponge with orientated wires in the z-direction, in aluminium, monel or phosphor bronze. This low-cost gasket solution allows EMI shielding by creating an electrical path between the mating surfaces via 400 contact points per square inch (6.2 per square mm). They are ideally used with compression stops to allow the correct deflection for optimal performance.
POLA Solid or POLA Sponge are composite electromagnetic interface (EMI) shielding and environmental sealing gasket materials, consisting of hundreds of individual fine wires embedded into the z-axis of solid or sponge elastomer. These products can easily be integrated into existing application assemblies, making the switch from a non-EMI solution possible.
Available in various flat seal configurations (including sheets, strips and die-cut parts) with comparable performance at a fraction of the cost of alternative solutions that provide both EMI shielding and weather sealing performance, as well as the opportunity to exactly match the galvanic potential of interfacing aluminium surfaces. Providing total cost of ownership savings through price point and corrosion rework reductions. POLA Sponge also provides the opportunity for increased design leniencies such as thinner flange requirements and reduced fastener quantities.
• Solid silicone binder: results in a robust gasketing material that can withstand greater fastener torque values as well as increased pressure and weather sealing requirements
• Silicone sponge: low-hardness closed cell that allows for reduced gasket load requirements to obtain weather sealing and EMI shielding performance
• Multiple wire alloy: allow for galvanic compatibility to be optimised between the gasketing and mating surfaces
• Galvanic compatibility allows for optimised corrosion mitigation and avoidance of related rework costs
• Cured in place oriented wires: will not dislodge, eliminating foreign object debris concerns
• Elimination of foreign object debris: ensures costly application rework due to electrical shorting can be avoided
• Wire 'bite-through' during gasket deflection: allows for non-conductive pressure sensitive adhesive to be used rather than the conductive systems more commonly offered with EMI gasketing solutions
Frequently Asked Questions
What are the benefits of using a POLA gasket?
POLA has good EMC shielding effectiveness (1GHz), weatherproofing, bite through on flange coatings to achieve metal to metal contact and offers grounding/earth bonding requirements.
What material are the wires available in?
Monel, nickel-copper alloy best for corrosion resistance or aluminium to resolve galvanic corrosion on aluminium flanges.
How do you resolve compression set or single-use of a POLA gasket?
Incorporate compression stops in the gasket.
What is the recommended compression % range on oriented wire in silicone gasket?
POLA Sponge: 10% min - 40% max, POLA Solid: 10% min - 30% max.
How is the material supplied?
POLA is usually supplied in sheets 228mm wide x 900mm long. HITEK can die-cut this material into gaskets and can join the material to make large 'picture frame' gaskets where required.