Product Focus: What is the Elastomeric Material Sorbothane®?


Developed by British scientist, and Fellow of the Royal Society of Chemistry, Dr. Maurice Hiles, Sorbothane is a proprietary, viscoelastic polymer. It is a thermoset, polyether-based, polyurethane material. In addition to being viscoelastic, it also has a very high damping coefficient and combines shock absorption, good memory, vibration isolation and vibration damping characteristics. While many materials exhibit one of these characteristics, Sorbothane combines all of them in a stable material with a long fatigue life and has a low creep rate compared to other polymers (rubber, neoprene, silicone, etc.) Sorbothane has a superior damping coefficient that is effective over a very wide temperature range, compared to any other polymer. Effective operating temperature range is -29° to 72° Celsius (-20° to +160° Fahrenheit). Unlike fluid-based shock absorbers or foam products, it absorbs shock efficiently for millions of cycles and eliminates the need for metal springs to return the system to its equilibrium position after absorbing a shock.


Sorbothane turns mechanical energy into heat. As the material is deformed, molecular friction generates heat. This “lost energy” is called hysteresis. Energy is translated perpendicularly away from the axis of incidence, and its effect is pushed nearly 90° out of phase from the original disturbance. This phase shift, known as “Tan Delta,” is a measure of damping effectiveness.

The higher the value of Tan Delta, the greater the amount of damping that occurs.

Controlling Shock

High damping in a polymer reduces the impulse peak of a shock wave over a longer time frame. Sorbothane reduces the impact force up to 80 percent, and brings the mass slowly to rest.

A gradual deceleration affords better protection of delicate equipment.

Controlling Vibration

Low transmissibility (amplification) at resonance demonstrates the damping superiority of Sorbothane over other elastomers. Low transmissibility means less damage to sensitive components. Isolation at large frequency ratios also shows a capacity to isolate vibration.

Impact Absorption

Sorbothane is an elastomeric material that reduces impact energy within a system. Natural rubber is more elastic and can return energy to the system. High-energy return causes high rebound and increases the potential for damage. Sorbothane can decelerate parts and reduce peak forces during sudden stops in minimal sway space. Impact absorption up to 80 percent is achievable at proper dynamic deflections.

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