It’s hardly surprising the SBR Rubber Sheet (red rubber) is one of the most widely used gasket materials. Firm and smooth, it conforms readily to mating surfaces. Good tensile strength and abrasion resistance ensure durability, providing it’s not used in the wrong places. Here’s what you should know about using red rubber gasket material.
SBR Rubber Sheet: A Proven Elastomer
Red rubber is produced by blending Styrene Butadiene Rubber (SBR) with natural rubber. SBR was one of the first synthetic rubber materials, produced by polymerizing styrene and butadiene in a roughly 3:1 ratio. Invented early in 20th Century, production increased rapidly during WWII as supply chain challenges limited availability of natural rubber. SBR’s strengths include resistance to cracking, abrasion resistance and low cost. Unlike natural rubber, it hardens with age.
When natural rubber is added to SBR the result is a red-colored elastomer with the best characteristics of each. Several grades are available with varying properties. Hardness is in the range 75 – 80D on the Shore A scale. (For more information, refer to “Understanding Gasket Material Hardness”.) The main limitations of red rubber are a temperature range limited to -20 to 160°F and swelling when exposed to hydrocarbons.
Applications to Avoid with SBR Rubber Sheet
Red rubber is not suitable for use with oils and fuels like gasoline and diesel. It also offers poor resistance to chemicals, solvents and hydraulic oils. In addition, it is degraded by ozone, so electrical, (especially high voltage,) applications are best avoided.
Good Applications for SBR Rubber Sheet
Red rubber gaskets perform well when sealing against air and water, both hot and cold. Saturated steam is also usually sealed effectively by red rubber.
SBR Rubber Sheet: Often the Right Choice
Many sealing and gasketing applications don’t need high-temperature capability or high levels of chemical resistance. When that’s the case red rubber is often a better choice than newer and more exotic materials. Produced in a range of sheet thicknesses, it lends itself to die as well as water jet cutting and can be a very cost-effective choice. For more information call or email the specialists at Hennig Gasket.
