Elastomers In Compression: Testing and Performance

        Although elastomers are often used in compression in applications, their performance capability and aging responses are often characterized by evaluating changes in physical properties in tension. Although properties in tension may be useful to note the degradation of a material’s response, would it not be more relevant and useful to note the change in a material’s compressive response as a reflection of a primary property critical to the performance in an application where components are placed in compression? This paper will discuss approaches to testing materials in compression and the relationship of these responses to the effect on their performance in applications. It will discuss the difference between ultimate properties and what will be termed as “intermediate equilibrium” responses. It will discuss current tests used to evaluate elastomers in compression, and suggest alternative tests that might be considered. These tests would be intended not only to just compare materials, but to predict the specific responses of materials in configurations, and their relationship to performance in applications. It will also discuss the relationship between these tests and their ability to define both the capability and service life for materials in configurations used in compressive sealing applications.