Compresion set

The permanent deformation that remains after the removal of a deforming compressive force

Polyurethane’s compression set is an important property to consider when your component must endure a compressive load. Examples of applications include bumpers, equipment mounts, vibration isolation pads, and rollers. Urethane’s compression set indicates how well the polyurethane will retain its elastic properties under compression.

A compound with low compression set will recover quite well, even if maintained in a compressed state for an extended period of time. Conversely, a compound with a high compression set will not recover as well. It will permanently retain much more of the deflection upon removal of the compressive stress.

Polyurethane’s compression set depends on a combination of basic properties such as modulus and the degree of molecular cross-linking, which result from the polyurethane’s formulation.

Urethane’s compression Set is expressed as a percentage related to the amount of permanent deformation caused by the compressive load.