Aircraft rubber gasket materials provide environmental sealing, electrical insulation, flame resistance, EMI/RFI shielding, noise control, and other properties. They’re supplied as sheets, rolls, extrusions and moldable compounds. Water jet cutting, a tool-free gasket fabrication process, can quickly convert stock materials into specific shapes with close tolerances. Moldable aviation rubber is used for gasket bonding.
Even if your company isn’t part of the aviation industry, you can learn a lot about rubber by examining the following elastomers. Remember, however, that aircraft rubber gasket materials may need to meet specific industry standards or regulatory requirements that are particular to the aviation industry. The aviation seals and aircraft insulation that are fabricated from these materials also need meet strict quality requirements.
Non-Conductive Elastomers and Reinforced Fabric
As their name suggests, non-conductive elastomers lack electrical conductivity. That’s because rubber, in either its natural or synthetic form, is a natural insulator. In aviation applications, rubber is used with aircraft wires, cables, electrical systems, and electronics (avionics). To impart improved tear resistance, elastomers such as nitrile, neoprene, silicone or EPDM can be reinforced with fabric.
EMI/RFI elastomers for aircraft rubber gaskets include compounds, such as silicones, that are filled with metal or metal-coated particles. These electrically conductive elastomers combine environmental sealing with protection against electromagnetic interference (EMI) and radio frequency interference (EMI). For EMI/RFI shielding plus fuel and chemical resistance, particle-filled fluorosiliciones are used.
Elastomer and Plastic Bonding
Elastomer and plastic bonding for aircraft provides high-strength adhesion to a variety of substrates. The base elastomer or plastic must support the function of the bonded assembly, such as a rubber-to-metal vibration mount. The adhesive system must provide a strong, reliable bond under both curing and service conditions. Aircraft products such as vibration mounts help to control noise.
FKM (Viton Rubber)
FKM refers to a category of fluoroelastomers that retain their oil and chemical resistance at elevated temperatures. DuPont™ Viton®, a proprietary FKM, is known for its ability to withstand high temperatures while maintaining its mechanical properties. Compared to fluorosilicones, FKM fluoroelastomers have greater tensile strength, tear strength, and abrasion resistance for aerospace and aviation applications.
Aircraft silicones resist moisture, chemicals, heat, cold, ozone, and ultraviolet (UV) radiation. This family of aviation elastomers is also stable, flexible, and visually appealing for use inside the cabin or cockpit. The advantages of silicone for aircraft gaskets include:
- Good thermal stability and low chemical reactivity
- Excellent resistance to ozone, sunlight, and oxygen
- Consistent properties at high and low temperatures
- Water and moisture resistance for watertight seals
- Good electrical insulation and excellent gas permeability
- Come in a range of durometers and custom colors
- Available in special grades and with filler materials
Aviation silicones are supplied as sponge, solid, and foam materials. For resistance against cracking during repeated take-offs and landings, these elastoemrs come in grades with high flex-fatigue resistance.
Aircraft neoprene resists fire and withstands sunlight, ozone, and weather. Specific grades of neoprene can meet flame, smoke and toxicity (FST) requirements such as Bombardier 800-C. The advantages of neoprene rubber gaskets include:
- Resistance to petroleum-based products such as oils and greases
- Physical toughness, including resistance to damage from twisting or flexing
- Resistance to ozone, water, weather, and a wide range of temperatures
- Polymerization that supports custom compounds with specialized properties
Applications for aircraft neoprene include door and hatch seals, window seals, hose covers, vibration mounts, and shock absorbers. Neoprene is also used with HVAC units, electrical or electronic enclosures, and weather stripping for fire doors.
Aircraft EPDM resists sunlight, ozone, oxygen, aging, acids, alkalis, water, and severe weather conditions. This aviation rubber also provides excellent color stability and high heat resistance. With its strong combination of thermal and mechanical properties, EPDM is a good choice for aircraft door and window seals. EPDM’s main disadvantage is its poor resistance to certain categories of fuels and chemicals.
Aircraft Rubber Gasket Materials and Custom Fabrication
Elasto Proxy, an AS9100D certified company, custom-fabricates a variety of aircraft rubber materials. We specialize in low-to-medium volume manufacturing and use water jet cutting so that you don’t have to wait for or pay for tooling. Elasto Proxy also offers design assistance, gasket bonding, and a range of value-added services that can save the aircraft industry time and money.
Do you need aircraft rubber gasket materials and custom fabrication? To learn more, contact us.