Synthetic rubber materials like SBR were developed to increase the supply and compensate for the limitations of natural rubber. For most of these man-made elastomers, while they excel in some regards, they fall short in others. Poor weather and ozone resistance are two of the biggest weaknesses.
Butyl rubber is a synthetic material that plugs this gap. Suitable for a range of sealing applications, it also has great damping and permeability characteristics. Here’s a closer look.
Butyl Rubber Basics
As polymerized at the factory, butyl rubber is white or colorless. It’s usually blended with carbon black to make it black, although other colors are possible.
Butyl rubber is much more dense than other synthetic rubbers, so it’s heavier, but this means it’s a very good absorber of vibration. The same chemical structure that creates high density also renders it impermeable to liquids and gases. (Other synthetic rubber materials like SBR and EPDM have a degree of gas permeability.)
Butyl rubber is on the softer side, (It’s available with Shore A ratings of 40 to 90 but is usually around 65), and has a working temperature range of -40 to 285°F. It’s also resistant to water, dilute acids, and animal and vegetable oils.
Limitations of Butyl Rubber
Butyl rubber will tend to take a compression set, limiting its use as a gasket in applications where the joint will be opened up periodically. Its abrasion resistance is only moderate and it is attacked by hydrocarbon fuels and oils.
Good Applications for Butyl Rubber
The biggest market for butyl rubber is automobile tires, where it’s used as a liner material. In terms of seals and gaskets, applications include:
- Tank liners
- Pond liners
- Cushioning
- Shock absorbers
- Flange and full-face gaskets, especially for outdoor applications
Butyl Rubber Sheet Cut to Shape
Ask for butyl rubber when you need impermeability, weather-resistance or cushioning. Hennig Gasket & Seals has butyl rubber sheet form and a range of thicknesses. We can die, flash or waterjet cut it to the exact size and shape you need. Contact us to discuss your needs and get a quote.
