UV, ozone and weather resistance: why EPDM rubber is superior
For rubber products working outdoors — under the sun, at variable temperatures and in a polluted atmosphere — the greatest enemies are UV rays and ozone. A material not resistant to these factors cracks and hardens in a short time. This is precisely why EPDM has become the standard choice for outdoor applications.
Factors that age rubber
- UV radiation — breaks down polymer chains and creates fine cracks on the surface.
- Ozone — causes deep cracking in rubber under stress (ozone cracking).
- Temperature cycles — the hot-cold alternation fatigues the material.
- Moisture and rain — lead to hydrolysis and swelling in some elastomers.
Why EPDM stands out
The molecular structure of EPDM (ethylene-propylene-diene monomer) has a saturated main chain; this minimises the double bonds that ozone and UV can easily attack. As a result, the material retains its elasticity outdoors for years. More detailed information about the basics of EPDM is available in the article what is EPDM rubber.
Wide temperature range
EPDM retains its properties from approximately -40 °C to +120 °C (higher for short periods), which makes it ideal for roofing, facade, window and automotive seals.
Comparison with other materials
Although NBR is excellent against oil, it is not ozone-resistant outdoors. Natural rubber has high mechanical properties but ages quickly under UV. Silicone has a wide temperature range, but its mechanical strength is lower. For the full differences, see the article comparison of EPDM, NBR and silicone.
Where NBR is more suitable
In places in contact with oil and fuel, not EPDM but NBR (oil-resistant rubber) should be chosen. That is, material selection always depends on the working environment.
Typical EPDM applications
- Window and door sealing profiles
- Roof membranes and waterproofing
- Automotive and railcar seals
- Sealing in water and steam systems
An EPDM product manufactured with the right formulation and quality control can serve for decades. If you are looking for a durable solution for outdoor use, take a look at our EPDM product range and for your project get in touch with us.