In industrial materials, one formula does not fit all. This is specially true with elastomers. Take EPDM – Ethylene Propylene Diene Monomer. For many uses, EPDM is an excellent material. It’s resistant to aging from ozone and ultraviolet rays and offers good resistance to heat and chemicals. The automotive industry and the construction industries use a lot of EPDM, due to its excellent resistance not only to ozone and UV but general weathering.
At Trelleborg IH, we use EPDM mostly for outdoor hoses or hoses for chemical transfers or high temperature.
But there’s one use we always avoid: use with oil products (hydrocarbons, mineral or vegetable oils to be more specific). That’s because EPDM will absorb oil in a way that weakens its properties.
Fortunately, we have nitrile butadiene rubber (NBR), a synthetic rubber, the most commonly used elastomer for oils. The petroleum and automotive industries use a lot of NBR, because it has a limited appetite for fluid hydrocarbons and does not alter as easily as EPDM. It’s often used for hydraulic hoses, hoses used to fill your car with petrol, and hoses for delivering heating oil.
But there is a tradeoff here too: while NBR is relatively resistant to aggressive chemicals, it is more sensitive to aging from environmental factors and abrasion. However, it is possible to formulate compounds that can strengthen its performance.
Our chemists formulate compounds according to the application needed, finding the right elastomer and the ingredients the formula needs to compensate for the elastomer's weak points.
That is why, though they might be based on the same elastomer, hoses may perform in very different ways.