Full definition
The ability of an elastomer to return stored elastic energy after deformation, expressed as a percentage of input energy recovered. Measured by the Bashore rebound test (ASTM D2632): a steel plunger is dropped from a fixed height onto the rubber specimen, and the rebound height is recorded as a percentage. High-resilience materials: NR (80%), BR (85%), silicone (55-65%). Low-resilience (high-damping) materials: butyl IIR (15-20%), chlorobutyl (18%), EPDM (40-55%). Resilience is the inverse of hysteresis — energy not recovered is dissipated as heat. For dynamic applications (tires, vibration mounts, belt body), high resilience means less heat buildup and longer service life. For damping applications (shock absorbers, engine mounts, sound insulation), low resilience provides better energy absorption. The Bashore rebound test is quick (seconds per sample) and widely used for incoming material QC. Per ASTM D2632. Testing at standard temperature (23°C) is critical as resilience is highly temperature-dependent.