A customer named Jason (the real person’s name was changed to protect his identity) once visited us and asked “What is EPDM?” as well as what it could be used for. It seemed as though he had done a bit of his own research, and was ultimately wondering whether or not EPDM rubber would suit the needs of his application. He was looking for a rubber that could be used to make a relatively small rubber product, known as a gasket. More specifically, the gasket would need to be operable in an outdoor machine that would be seeing some diluted alkalis with a temperature range of about 150 degrees Fahrenheit. Could a material like black EPDM be able to fulfill Jason’s specific gasket needs? Before determining whether or not that was so, let us talk a little about the characteristics of this rubber.

What is EPDM: E.P.D.M. sheets are a synthetic elastomer; the name stands for ethylene propylene diene monomer, and it is a very long chemical term. Now, I’m sure you’re asking yourself what all that means. Essentially, scientific innovations have produced methods of mixing certain monomers (atoms) together in various proportions; this process is called polymerization. The linking together of atoms is done for the purpose of achieving a specific end result, or to have a material possess a certain set of qualities or resistances. In this case ethylene, propylene and diene were mixed together to make the end product EPDM rubber. These chemicals have given this rubber compound a great resistance to ultraviolet rays, some chemicals and it is able to operate in moderate heat (up to 212 degrees Fahrenheit).

UV Rays: EPDM has been designed to resist being damaged in applications that are going to be exposed to the elements, like outdoors and ultraviolet rays. For example, say you had a porch light fixture that needed a gasket against the wall, or better yet, if you had a playground that needed a nice rubber surface, EPDM rubber would be the best type of rubber for you in both of these applications. Did you know that the seals around your car windows are generally made from EPDM? How about rubber roofing? Not surprisingly, that is also made from E.P.D.M. sheets, because a material which can stand up to the elements is necessary for this application.

Chemical Resistances: The online dictionary Wikipedia sums up the different types of chemicals EPDM resists quite effectively: fireproof hydraulic fluids, ketones, hot and cold water, and alkalis. Applications that involve most oils, gasoline, kerosene, aromatic and aliphatic hydrocarbons, halogenated solvents, and concentrated acids should be kept away from black EPDM. While it does not actually define what the term “failing” means, we know in other applications volume swell of the rubber is too great to be useful in its original application. So when Jason asked if E.P.D.M. sheets were right for his application we needed to make sure that he clearly defined which types of chemicals were going to be present in his application.

Ultimately, Jason made a choice of black EPDM for his gasket. Again, he wanted a material that would withstand a temperature range of about 150 degrees Fahrenheit, could operate when exposed to some diluted alkalis, and would have no difficulties carrying out its task when outdoors. Looking at the information we have found, it appears that Jason was in fact correct in choosing EPDM rubber for his project, as its unique properties were well suited for the task. Thankfully we stock EPDM in several gauges and have a small minimum order so if he needs just a few of these gaskets we can help him! So next time someone asks you “what is EPDM?” You’ll know enough about it to point them in the right direction.