Full definition
A laboratory test method that exposes rubber specimens to elevated temperatures (typically 70-150°C) in an air oven for defined periods (22, 70, or 168 hours) to simulate long-term degradation and predict service life performance. After aging, specimens are tested for changes in hardness, tensile strength, and elongation at break compared to unaged controls. Per ASTM D573 (air oven aging — most common method) and ISO 188. Acceptance criteria vary by application: typical specifications allow maximum changes of ±15% tensile, -40% elongation, and ±10 points hardness after aging. The Arrhenius equation allows extrapolation of service life from accelerated data: each 10°C increase approximately doubles the degradation rate. For example, 70 hours at 100°C may approximate 1 year at ambient temperature for NR. Additional specialized aging tests: ASTM D1149 (ozone exposure), ASTM D750 (cut growth), ASTM D572 (oxygen bomb). Results are essential for qualifying materials for automotive (SAE, OEM specs), industrial (ISO 14890 for conveyor belt covers), and military applications. Critical for comparing compound formulations during development.