EMI shielding gaskets or extruded or cut. The raw material is a loaded silicone (Ni/C or Ag/Al). We can also use a fluorosilicone material for higher resistance to oil or hydrocarbon.
These EMI shielding gaskets or harder than standard silicone gasket (around 65 Shore A). However it is mainly used for high ingress protection level (IP).
These EMI shilding gaskets are used for electromagnetism protection and sealing (IP) using one kind of gasket.
Due to the high resistance and stability of the loaded silicone it is wildly used in medical, military, telecom and nuclear projects.
Loaded silicone used to manufacture EMI shielding gaskets:
Silicone loaded with conductive graphite (C) and nickel (Ni) particles (Ni/C conductive gasket)

Silicone loaded with conductive silver (Ag) and aluminum (Al) particles (Ag/Al conductive gasket)

Silicone loaded with graphite and nickel (Ni/C) VS silver and aluminum (Ag/Al) :
Color:
- Ni/C : Dark grey
- Ag/Al : White/Grey
Volume resistivity:
- Ni/C : 0.1 Ω*cm
- Ag/Al :<0.008 Ω*cm
Density:
- Ni/C : 2.0 to 2.3 g/cm³ ±0.1
- Ag/Al : 2.1 g/cm³ ±0.05
Hardness:
- Ni/C : 55 to 75 Shore A ±5
- Ag/Al : 65 to 78 Shore A ±5
Tensile strenght:
- Ni/C : 1.4 to 2 MPa
- Ag/Al : 1.5 to 2MPa
Elongation at break:
- Ni/C : 60 (fluorosilicone) to 100%
- Ag/Al : 30 (fluorosilicone) to 50%
Tear strength:
- Ni/C : 4.0 to 6.2 kN/m
- Ag/Al : 5.3 kN/m
Compression set:
- Ni/C : 25 to 30%
- Ag/Al : 30%
Temperature range:
- Ni/C : -45°C to +150°C
- Ag/Al : -55 to 160°C
EMI/EMC Shielding effectiveness (from 100MHz to 18GHz):
- Ni/C : 95dB to 115dB
- Ag/Al : 100dB to 115dB
Flame retardant (UL94 certification):
- Ni/C : HB to V-0
- Ag/Al : HB to V-0
Reach and RoHS certification:
- Ni/C : Certified
- Ag/Al : Certified