Silicone Rubber Gasket 101 | Materials, Properties, Applications
What Are Silicone Rubber Gaskets?
Gaskets are mechanical seals used to fill in the spaces between two mated surfaces. They are engineered to prevent fluids (gas or liquid) from leaking out of or into the system between the two surfaces while under compression. In some assemblies, they serve as a barrier that keeps two components separated to protect them against friction damage.
These sealing devices can be made from a wide range of materials depending on the requirements and restrictions of the application. One of the most commonly used is silicone rubber. It exhibits many advantageous characteristics that make it suitable for various industrial and commercial applications. For example, its excellent resistance to extreme temperatures, ozone, and ultraviolet (UV) radiation enables it to be used in outdoor environments without fear of premature degradation.
Types of Silicone Gasket Materials
Silicone rubber comes in many types, grades, and forms to suit different applications. The ones commonly used to make gaskets are:
- Solid silicone rubber. This material has a dense molecular structure. It can have low or high durometers. The former is suitable for seals with low closure force requirements, while the latter is suitable for seals with high closure force requirements.
- Sponge silicone rubber. This material has a cellular structure that provides some cushioning and padding properties. It is available in two basic types: open-cell and closed-cell. Open-cell sponge silicone has interconnected pockets that allow air, chemicals, and water to pass through when it is uncompressed. Closed-cell sponge silicone has pockets that are filled with nitrogen to prevent anything from passing through it.
- Foam silicone rubber. This material offers flame resistance. It is available in soft, medium, firm, and extra-firm grades and open-cell, closed-cell, and combined open-cell/closed-cell variations.
- Liquid silicone rubber (LSR). This material is a two-part material system that must be mixed and heat cured before use. It offers fast and inexpensive molding operations, clean curing operations, and low durometer options.
These silicone rubber gasket materials can be made in various grades, such as FDA-compliant, UL-compliant, and MIL-SPEC, and shaped into sheet, roll, and other standard or custom profile forms to meet different industry and application requirements.
Why Use Silicone Rubber?
Silicone rubber exhibits many properties that make it ideal for use in gaskets, such as:
- Resilience over a broad temperature range. Silicone rubber is resistant to chemicals, moisture, oxygen, ozone, and sunlight, and it maintains these qualities in both extremely low and extremely high temperatures.
- Resistance to permanent compression set. Silicone rubber will return to its original shape after being subjected to compressive forces.
- Availability in various durometers, colors, and specialty grades. Silicone rubber comes in numerous hardness levels, colors, and grades, so it can be used for many applications.
Common Applications of Silicone Rubber Gaskets
Some of the industries that commonly rely on silicone rubber gaskets include:
- Food Processing
Contact Us for Silicone Gasket Solutions
Want additional information on silicone rubber gaskets? Ask the experts at Mercer Gasket & Shim! We’ve supplied gaskets and other industrial products for over 100 years. We have what it takes to answer or address any questions or concerns you may have about these products.
If you need standard or custom gaskets, we’ve got you covered. Our extensive selection of gasket materials enables you to choose the best material for your application. Additionally, as an ISO 9001:2015 company, you can depend on us for quality products and services. Our standard is 100% defect-free products delivered 100% on time.