Pressure tests on elastomers

Pressure tests on elastomers are material testing methods in which a test specimen made of rubber is pressed between two plates to determine its behavior under pressure and its ability to return to its original shape. The three most important pressure tests for elastomers are determining the pressure deformation residual, the pressure stress-strain test, and the pressure stress relaxation. Pressure tests are primarily used for Seals and Buffer It is important to use elastomers because these components are mostly subjected to pressure during use.

How does a pressure test work?

During a pressure test, a mostly cylindrical elastomer test specimen is pressed between two parallel plates, and the required force is measured. Whether the plates are lubricated or whether the test specimen adheres to them has a significant impact on the result, as friction hinders lateral expansion. The testing standards therefore precisely determine the test specimen size, compression, test speed, ambient temperature, and plate condition.

Which values are determined by pressure tests?

The pressure-strain-deformity test determines the compressive strength of an elastomer. The compressive strength depends strongly on the shape factor, the ratio of the loaded area to the freely expanding area. The pressure-strain relaxation measures how strongly the opposing force of a swollen elastomer decreases over time. For seals, the pressure-strain relaxation is particularly important because it directly shows the loss of sealing force during installation. The dynamic pressure test loads an elastomer with alternating compression and thereby determines its dynamic stiffness and damping. These characteristics are crucial for vibration dampers and motor bearings. How well an elastomer recovers after prolonged compression is described in Compression set, which is explained in detail in the linked article.