EPDM vs NBR vs Silicone: Comparison of Seal Materials
Choosing the right elastomer for a seal or profile directly determines the service life of the product. In practice, three materials are most often compared: EPDM, NBR and silicone. Each has its strengths and weaknesses, so there is no universal answer — the choice depends on the operating conditions.
Quick comparison table
| Property | EPDM | NBR | Silicone |
|---|---|---|---|
| Operating temperature | -50…+150 °C | -30…+100 °C | -60…+200 °C |
| Oil/fuel resistance | Poor | Excellent | Moderate |
| Weather, ozone, UV | Excellent | Poor | Excellent |
| Water/steam resistance | Very good | Moderate | Good |
| Price | Low | Moderate | High |
When to choose EPDM
EPDM is the ideal choice for applications outdoors and in contact with water, steam and ozone. Window and door seals, roofing membranes, drinking water systems and cooling circuits are typical examples. However, EPDM swells and is damaged in contact with mineral oils and fuel — it should be avoided in such places. For detailed information, see our article about EPDM rubber.
When to choose NBR
NBR (nitrile rubber) is indispensable in contact with oil, diesel, petrol and hydraulic fluids. It is the standard material for automobile engines, hydraulic cylinders and fuel systems. Its drawback is that it ages quickly outdoors under the influence of ozone and UV. For technical details, take a look at the NBR oil-resistant rubber section.
When to choose silicone
Silicone retains its elasticity over an extreme temperature range — at both very low and very high temperatures. It is suitable for the food industry, medical equipment, ovens and electrical insulation. Its mechanical strength and oil resistance, however, are relatively low. More application examples are in the applications of silicone rubber article.
The main rule for selection
When choosing a material, ask three questions: which fluids will it contact, what is the operating temperature and will it work outdoors. If there is contact with oil — NBR; if outdoors and water — EPDM; if extreme temperatures — silicone. Sometimes, however, more specialized materials are needed, for example Viton (FKM) for high temperatures.
As NUR KAUÇUK, we prepare the appropriate compound for each application in our laboratory. For ready-made solutions, see our products or contact us to discuss your project.