The TR10 value
Standards: ASTM D 1329, ISO 2921
The TR10 value describes the temperature (in °C) at wich a stretched sample (stretching rate 25% or 50%) reaches a recovery rate of 10% after freezing. For an evaluation of an O-rings sealing behavior at low temperatures, the TR10 value has a high significance and represents a conservative low-temperature limit. We know from experience that even O-rings in dynamic applications and O-rings that have to face pressures at low temperatures keep sealing till this temperature. For static applications, temperatures of up to 10°C – 15°C below the TR10 value may still be acceptable. Usually, the TR10 value is taken at standard test pieces punched out of 2mm test plates, but with a special device, O-rings with a cord-size of up to 3.53mm and an inner diameter higher than 15mm can be measured. From an application oriented point of view, the TR10 value is the most significant reference value for O-ring- and most other sealing-applications at low tem-peratures and is furthermore determined as a material property for many different elas-tomere materials. O-Ring-Prüflabor Richter offers this testing method since 2010.
The TR – testing describes the continous defreezing behavior of a sample and therefore describes the temperature-dependent elasticity of a material below room-temperature. This data helps to evaluate different materials concerning their low-temperature behav-ior. The difference between TR10 and TR70 value, for example, describes how long the material needs to re-achieve its full elasticity.