Quick Answer
ECO emphasizes low permeability, fuel/oil resistance and ozone durability; HNBR emphasizes strong mechanical properties, heat aging and oil resistance in demanding dynamic components.
ECO vs HNBR: practical comparison
| Selection factor | ECO | HNBR |
|---|---|---|
| Permeability | Low | Moderate/grade-dependent |
| Mechanical strength | Good compound-dependent | Often a major HNBR strength |
| Heat aging | Good | Often stronger |
| Ozone/weather | Strong | Strong |
| Typical role | Fuel hose/vapor/seals | Belts, seals, oilfield and high-duty dynamic parts |
How to choose
Use ECO where barrier performance and fuel vapor control are major requirements; use HNBR where high mechanical/dynamic and temperature performance dominate.
Important: Ratings describe general polymer-family tendencies. Exact performance can change materially with grade, formulation, cure system, fluid composition, temperature and test method.
Frequently asked questions
Durability depends on the failure mode. HNBR can excel mechanically, while ECO can excel in permeability-related service.
Blend compatibility and property trade-offs require formulation development; do not assume a simple blend is beneficial.