Compression testing provides information about the compressive properties of the test specimen. As both rubber and plastic materials are frequently used in compressive applications, compression test procedures are common for these materials. These properties include compressive strength, compressive stress, compressive strain, deformation, compressive yield point and yield strength, Modulus of Elasticity, Secant Modulus, and slenderness ratio.
During a compression test, the test specimen is placed on compression platens or a specialized compression fixture and is compressed by applying load to the specimen. Compression testing for plastics and rubber materials often require a uniform, controlled speed rate or constant-rate-of-crosshead movement. Compression testing may be set up to determine the force required to cause a specified deflection, which is the change in thickness of the test specimen, or to measure the deflection when a specified compressive force is applied to the specimen. The sample may be placed in a compressometer with displacement transducers that record the amount of deformation on the specimen. Depending on the specimen geometry and dimensions, an extensometer or a deflectometer may also be used to measure the deformation.