DESCRIPTION: POLASHEET and POLASTRIP gasketing are composite EMI shielding and weather sealing materials. Either solid or sponge silicone may be specified as the weather seal. In POLASHEET gasketing, individual monel or aluminum wires embedded in the silicone and oriented perpendicular to mating flange surfaces provide the EMI shielding. Wires are crimped for resiliency. Solid silicone POLASHEET gasketing is available with high-tack pressure-sensitive adhesive backing. In POLASTRIP gasketing, EMI shielding is provided by monel or aluminum knitted wire mesh embedded in silicone. POLASHEET and POLASTRIP gasketing with solid silicone weather seal are recommended for sealing under high pressure conditions. The silicone seal is rated for use at temperatures from –70°F (–56.7°C) to +500°F (+260°C). Sponge silicone is used only for pressures below 5 psi (0.03 MPa) and for rain, drip, dust and ventilating air seals.
