Under compressive load, rubber behaves like an incompressible liquid—when rubber is compressed, its shape changes but not its volume. In contrast to a liquid, however, rubber more or less returns to its original shape. These properties and the design of the rubber component influence how much it is compressed under a given load. The fact that rubber is incompressible must be taken into account during design. Solid rubber must always have the possibility to bulge under compressive load and must never be completely enclosed.
Compressive load and tensile load
Rubber is mostly used under compressive loads, and most types of rubber, apart from urethane rubber, silicone rubber, and EPDM rubber, have a significantly shorter lifespan under tensile load than under compressive load. How the rubber behaves under compressive load is of great importance for its function. An important property is how much the rubber deforms at a certain load. A certain deformation may be desirable, e.g., when using rubber for vibration dampers.