As one of the most popular synthetic rubbers, silicone elastomers exhibit an exceptional array of properties that make them ideal for a variety of different industries and applications. Known for their resistance to extreme temperatures, silicones are often used as gaskets in aerospace parts and in vent ducts. They also provide an effective barrier to UV and ozone, and maintain their flexibility in cold environments. Additionally, silicones are highly resistant to a wide variety of chemicals and are non-toxic and odorless, making them ideal for medical-grade and food-grade sealing.
Silicone rubbers are produced as solids, liquids, pastes and greases. They are typically cured/crosslinked using peroxide crosslinkers (benzoyl, dicumene, 2,4-dichlorobenzoyl or t-butyl peroxide) or platinum catalysts to produce a durable cured seal. They can be modified by the addition of fillers (such as pyrogenic silica with very high BET surface area) and stabilizers to alter their performance characteristics. Flame retardants (such as platinum compounds, carbon black, aluminum trihydrate or zinc) are added to reduce the hazard of ignition in hot air.
Solid silicones are available in a wide range of durometers, from 10 to 70 on the Shore A scale. Higher durometers require greater closure force to achieve a tight seal. These types of gaskets are commonly used in metal enclosures and require a precise bolt pattern to ensure proper compression. They are also used with silicone hoses in automotive engines, in kitchen appliances, home repair and hardware products and for medical purposes including surgical devices.
Deutsch
