Polymers — Behavior under Pressure

The extent to which the elastic properties of a seal remain intact after being subjected to a constant load of longer duration is very important.

To test this, an elastomer seal was loaded with a force of 3 N and then relieved to 5 mN. Following a 40-hour load time, 21% compression was observed. After a 30-minute relief period, the compression had reversed by 16.2%; after 60 min, by 16.8%. The visco-elastic properties of the elastomer were such that the sample did not return to its original length even after 30 hours. (measurement with TMA 402 F1 /F3 Hyperion®®)