Seals are available in a variety of elastomeric materials, two of the most popular being silicone and fluorosilicone. Both materials can stretch and return to their original shape. Silicone and fluorosilicone seals, however, have distinct advantages that set them apart from each other.
What Are Silicone Seals?
Silicone seals are characterized by a silicone composition. They are made of a synthetic polymer with rubber-like properties known as polysiloxane or, more commonly, silicone.
Silicone has been around since the early 1900s. It was pioneered by American chemist James Franklin Hyde. Hyde discovered that by mixing silicon compounds, he was able to create a strong and elastic new material. Silicone has since been used in everything from adhesives and lubricants to integrated circuits, kitchen utensils and seals.
What Are Fluorosilicone Seals?
Fluorosilicone seals are characterized by a fluorosilicone composition. Fluorosilicone is essentially a modified version of silicone. It’s a silicone-based rubber with properties of both fluoropolymers and silicones, hence the name “fluorosilicone.”
Fluorosilicone seals share many of the same properties as silicone seals. They are both very durable with a maximum shelf life of up to 20 years. They are also resistant to heat and chemicals. Silicone and fluorosilicone seals, however, aren’t the same.
Differences Between Silicone and Fluorosilicone Seals
Silicone seals are very flexible — even more so than fluorosilicone seals. They maintain their elasticity even after being repeatedly stretched and deformed.
Silicone seals can handle extreme temperatures. Many silicone seals can withstand temperatures as low as 60 degrees Fahrenheit and as high as 400 degrees Fahrenheit.
In addition to handling extreme temperatures, silicone seals are UV resistant. You can use them outdoors without fear of the sun’s UV rays destroying or degrading them.
Fluorosilicone seals are still flexible, but they aren’t quite as flexible as their silicone counterparts. On the other hand, fluorosilicone seals offer a superior level of chemical resistance. They can handle exposure to fuels, oils, solvents and other harsh chemicals better than silicone seals.
Fluorosilicone seals may also cost more than silicone seals. This is because they are essentially made of a modified version of silicone. Fluorosilicone is a more advanced material, resulting in a higher cost of production for fluorosilicone seals.
In Conclusion
You can find o-rings, gaskets and other seals made of silicone and fluorosilicone. Silicone and fluorosilicone are two common elastomeric materials in which seals are made. Silicone seals are prized for their flexibility and overall durability, whereas fluorosilicone seals offer better chemical resistance.