ECO-CO
Grade · default condition
also Hydrin
Standard choice for fuel and vacuum hose, diaphragms and seals needing oil resistance plus −40 °C flexibility.
Values for the ECO-CO condition
Other ECO grades and fills
ECO is listed in 9 conditions; see the grade overview at ECO.
Compare all 9 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Shore A 50 | Soft diaphragms, bellows and low-clamp-force gaskets. | — | 9 | 400 | 12 Shore D |
Conductive / antistatic grade | Choose for fuel hose liners that must dissipate static charge per SAE J30/J2260 requirements. | — | 10 | 220 | 23 Shore D |
GECO / ETER | Use where sulfur or peroxide cure, lower compression set and the best low-temperature flexibility are required. | — | 11 | 280 | 18 Shore D |
Shore A 60 | Hose inner liners and flexible fuel-system components. | — | 11 | 320 | 16 Shore D |
Peroxide-cured GECO compound | Pick for static seals needing low compression set and no lead/thiourea cure residues. | — | 11 | 230 | 22 Shore D |
ECO-CODefaultThis page ECO | Standard choice for fuel and vacuum hose, diaphragms and seals needing oil resistance plus −40 °C flexibility. | — | 12 | 250 | 22 Shore D |
Shore A 70 | Default seal/O-ring and hose hardness; best balance of strength and set. | — | 12 | 250 | 22 Shore D |
Epichlorohydrin homopolymer | Pick when the lowest gas/fuel permeability and best hydrocarbon resistance matter more than cold flexibility. | — | 13 | 220 | 22 Shore D |
Shore A 80 | Higher-pressure seals, backup rings and stiff mount elements. | — | 13 | 180 | 30 Shore D |
What is ECO-CO?
ECO-CO is ECO in the ECO-CO grade — standard choice for fuel and vacuum hose, diaphragms and seals needing oil resistance plus −40 °C flexibility. ECO-CO has a tensile strength of 12 MPa (1.74 ksi), weaker than 76% of polymer grades. Elongation at break is 250% and the elastic modulus is 0.01 GPa (8.7×10⁻⁴ Msi). ECO-CO has a density of 1.36 g/cm³ (0.0491 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is -40°C (-40 °F).
Advantages
- Good UV / weathering resistance — 88/100, better than 90% of polymer grades
- Forms and bends easily — 85/100, better than 81% of polymer grades
- Ductile — tolerates forming and impact — 250%, better than 79% of polymer grades
Limitations
- Difficult to machine — 25/100, worse than 93% of polymer grades
- Absorbs moisture — dry before molding — 1.5%, worse than 91% of polymer grades
- High mold shrinkage — 2.3%, worse than 89% of polymer grades
- Low stiffness — 0.01 GPa (8.7×10⁻⁴ Msi), worse than 86% of polymer grades
- Difficult to weld — 10/100, worse than 82% of polymer grades
ECO-CO properties
Typical room-temperature values for ECO-CO; 19 are specific to this condition. Other listed values are ECO reference data and may not represent this condition. Bars are the position among polymer grades.
Physical4
ECO-CO has a density of 1.36 g/cm³ (0.0491 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is -40°C (-40 °F).
Mechanical8
ECO-CO has a tensile strength of 12 MPa (1.74 ksi), weaker than 76% of polymer grades. Elongation at break is 250% and the elastic modulus is 0.01 GPa (8.7×10⁻⁴ Msi).
Thermal8
ECO-CO is rated for continuous service to 125°C (257 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 60% of polymer grades. Thermal expansion is 180 µm/m·K (100 µin/in·°F).
Electrical4
ECO-CO is an electrical insulator with a dielectric strength of 16 kV/mm (406.4 V/mil) and a resistivity of 1×10⁸ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (78/100), worse than 61% of polymer grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of ECO-CO takes about 115 MJ of energy and emits 4.8 kg of CO₂ — more than 70% of polymer grades. Typical recycled content is 0%.
Manufacturability5
ECO-CO's machinability is poor (25/100, worse than 93% of polymer grades); weldability not recommended (10/100); formability excellent (85/100).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ECO-CO
Is ECO easy to machine?
Cured ECO is best die-cut, water-jet or cryo-deflashed; grinding/turning needs sharp tools and freezing to avoid tearing and smearing.
Can ECO be welded?
Not weldable as a thermoset; joints are made by adhesive bonding (cyanoacrylate/epoxy on chlorinated-primer or plasma-treated surfaces) or by co-vulcanization during molding.
Can ECO be formed, bent or molded?
Mills and extrudes easily but is tacky and scorch-sensitive; compression/injection cure at 160–190 °C with an MgO-type acid acceptor, and post-cure 2–4 h at 150 °C for lowest compression set.
What surface finishes work on ECO?
Usually used as-molded in black; surfaces can be talc- or PTFE-dusted, plasma- or chlorine-treated for low friction, and adhesion to brass/steel inserts is achieved with standard rubber-to-metal bonding agents.
ECO chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| epichlorohydrin (ECH) unitschlorine-bearing repeat unit; ~30–38 wt% Cl in CO homopolymer | 55 – 75 | 68 |
| ethylene oxide (EO) unitsraises low-temperature flexibility, absent in CO homopolymer | 25 – 45 | 32 |
| allyl glycidyl ether (AGE)cure-site monomer, present only in GECO/ETER terpolymer | 0 – 8 | 0 |
| carbon black (N550/N774)phr in a typical 70 Shore A compound | 30 – 70 | 50 |
| plasticizer / process oil (ether-ester tphr | 0 – 20 | 8 |
| acid acceptor (MgO / hydrotalcite) + curphr; acid acceptor essential to trap evolved HCl | 3 – 10 | 6 |
ECO-CO — frequently asked
What is ECO-CO used for?
ECO-CO is typically used for fuel hoses, vacuum hoses, automotive seals and low-temp gaskets. In short: fuel resistance to -40 °C; inherently antistatic elastomer; low permeability to fuels.
What is the tensile strength of ECO-CO?
ECO-CO has a typical tensile strength of 12 MPa (1.74 ksi) — weaker than 76% of polymer grades. Strength varies by condition: see the 9 listed tempers.
Is ECO-CO easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of polymer grades). Cured ECO is best die-cut, water-jet or cryo-deflashed; grinding/turning needs sharp tools and freezing to avoid tearing and smearing.
Can ECO-CO be welded?
Not readily — weldability is rated not recommended (10/100). Not weldable as a thermoset; joints are made by adhesive bonding (cyanoacrylate/epoxy on chlorinated-primer or plasma-treated surfaces) or by co-vulcanization during molding.
What surface finishes work on ECO-CO?
Usually used as-molded in black; surfaces can be talc- or PTFE-dusted, plasma- or chlorine-treated for low friction, and adhesion to brass/steel inserts is achieved with standard rubber-to-metal bonding agents.
Can ECO-CO be formed, bent or molded?
Mills and extrudes easily but is tacky and scorch-sensitive; compression/injection cure at 160–190 °C with an MgO-type acid acceptor, and post-cure 2–4 h at 150 °C for lowest compression set.
What is the maximum service temperature of ECO-CO?
ECO-CO is rated for continuous use to about 125°C (257 °F), and briefly to 150°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Hydrin CO/ECO/ETER epichlorohydrin elastomer technical bulletins — Zeon Chemicals (2021)
- Engineered Materials Handbook Vol.2: Engineering Plastics / Rubber Products Manufacturing Technology — ASM International (1988)
- ASTM D2000 — Classification System for Rubber Products in Automotive Applications (type/class CH, CE) — ASTM (2020)
- ISO 1629 — Rubber and latices: nomenclature (CO, ECO, GECO) — ISO (2013)
- SAE J30 / SAE J2260 — Fuel and vapour hose requirements — SAE International (2018)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.