ECTFE GF25
Reinforced grade
ASTM D3275 · also Halar
GF25 = 25% glass-fibre reinforced compound
Use where stiffness, creep resistance and dimensional stability of a fluoropolymer part matter more than ductility.
Values for the GF25 condition
Other ECTFE grades and fills
ECTFE is listed in 5 conditions; see the grade overview at ECTFE.
Compare all 5 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Powder coating / rotolining grade | Pick for 0.5–2 mm thick pinhole-free linings on steel tanks, scrubbers, ducts and pumps in acid/chlorine service. | 28 | 40 | 200 | 73 Shore D |
Wire & cable / plenum insulation grade | High-speed extrusion grade for plenum-rated data cable jacketing where low smoke and flame spread are required. | 29 | 42 | 280 | 74 Shore D |
Conductive / antistatic (carbon-filled) grade | Carbon-black/carbon-fibre filled compound for static-dissipative tank linings and flammable-solvent handling. | 30 | 35 | 80 | 78 Shore D |
High-purity / semiconductor grade | Low-extractable, low-metal-ion resin for UPW and wet-bench fluid handling, filter housings and membrane supports. | 31 | 45 | 250 | 75 Shore D |
GF25This page 25% glass-fibre reinforced compound | Use where stiffness, creep resistance and dimensional stability of a fluoropolymer part matter more than ductility. | — | 60 | 6 | — |
What is ECTFE GF25?
ECTFE GF25 is ECTFE in the GF25 grade — use where stiffness, creep resistance and dimensional stability of a fluoropolymer part matter more than ductility. ECTFE GF25 has a yield strength of 31 MPa (4.5 ksi) and a tensile strength of 60 MPa (8.7 ksi) — weaker than 70% of polymer grades. Elongation at break is 6% and the elastic modulus is 5.5 GPa (0.798 Msi). ECTFE GF25 has a density of 1.86 g/cm³ (0.0672 lb/in³), heavier than 97% of polymer grades. Its glass-transition temperature is 65°C (149 °F).
Advantages
- Low moisture uptake — 0.01%, better than 97% of polymer grades
- Good UV / weathering resistance — 95/100, better than 95% of polymer grades
- Stiff — 5.5 GPa (0.798 Msi), better than 88% of polymer grades
- Readily welded — 80/100, better than 86% of polymer grades
- High service temperature — 150°C (302 °F), better than 79% of polymer grades
Limitations
- Heavy — 1.86 g/cm³ (0.0672 lb/in³), worse than 97% of polymer grades
- High embodied carbon — 11 kg CO₂/kg, worse than 90% of polymer grades
- High mold shrinkage — 2%, worse than 81% of polymer grades
- Poor heat conductor — 0.16 W/m·K (0.0924 BTU/hr·ft·°F), worse than 78% of polymer grades
ECTFE GF25 properties
Typical room-temperature values for ECTFE GF25; 10 are specific to this condition. Other listed values are ECTFE reference data and may not represent this condition. Bars are the position among polymer grades.
Physical7
ECTFE GF25 has a density of 1.86 g/cm³ (0.0672 lb/in³), heavier than 97% of polymer grades. Its glass-transition temperature is 65°C (149 °F).
Mechanical11
ECTFE GF25 has a yield strength of 31 MPa (4.5 ksi) and a tensile strength of 60 MPa (8.7 ksi) — weaker than 70% of polymer grades. Elongation at break is 6% and the elastic modulus is 5.5 GPa (0.798 Msi).
Thermal11
ECTFE GF25 is rated for continuous service to 150°C (302 °F). It conducts heat at 0.16 W/m·K (0.0924 BTU/hr·ft·°F), worse than 78% of polymer grades. Thermal expansion is 35 µm/m·K (19.4 µin/in·°F).
Electrical7
ECTFE GF25 is an electrical insulator with a dielectric strength of 80 kV/mm (2,032 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 74% of polymer grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of ECTFE GF25 takes about 210 MJ of energy and emits 11 kg of CO₂ — more than 89% of polymer grades. Typical recycled content is 0%.
Manufacturability8
ECTFE GF25's machinability is fair (50/100, worse than 73% of polymer grades); weldability very good (80/100); formability very good (75/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ECTFE GF25
Is ECTFE easy to machine?
Machinable with sharp, high-rake carbide tools, high speed and low feed; the material is tough and gummy, so use coolant/air blast and expect springback on tight tolerances.
Can ECTFE be welded?
Readily fusion, hot-gas and extrusion welded (liners and sheet) at 280–320 °C; adhesive bonding requires plasma or chemical surface activation.
Can ECTFE be formed, bent or molded?
Injection mould/extrude at 260–310 °C with corrosion-resistant (Hastelloy/nickel-alloy) barrels and hot runners; shrinkage 1.5–3.5 %, sheet thermoforms at 180–230 °C, powder applied electrostatically then fused at 260–290 °C.
What surface finishes work on ECTFE?
Non-stick, low-energy surface — no paint or plating without corona/plasma treatment; pigmented or textured grades preferred over polishing, and coatings are spark-tested for pinholes.
ECTFE 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 |
|---|---|---|
| chlorotrifluoroethylene (CTFE)≈50 mol%, alternating copolymer | 78 – 82 | 80.6 |
| termonomer / stabilizerminor modifier in some commercial grades | 0 – 1 | — |
| ethylene≈50 mol% | ≥ 18 (balance) | — |
ECTFE GF25 — frequently asked
What is ECTFE GF25 used for?
ECTFE GF25 is typically used for tank and pipe interior linings, wire and cable jacketing, chemical process equipment coatings and battery separator films. In short: low-cost fluoropolymer lining; strong permeation barrier; electrostatically applied powder coating.
What is the yield strength of ECTFE GF25?
ECTFE GF25 has a typical yield strength of 31 MPa (4.5 ksi) and a tensile strength of 60 MPa (8.7 ksi) — weaker than 70% of polymer grades. Strength varies by condition: see the 5 listed tempers.
Is ECTFE GF25 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 73% of polymer grades). Machinable with sharp, high-rake carbide tools, high speed and low feed; the material is tough and gummy, so use coolant/air blast and expect springback on tight tolerances.
Can ECTFE GF25 be welded?
Yes — weldability is rated very good (80/100). Readily fusion, hot-gas and extrusion welded (liners and sheet) at 280–320 °C; adhesive bonding requires plasma or chemical surface activation.
What surface finishes work on ECTFE GF25?
Non-stick, low-energy surface — no paint or plating without corona/plasma treatment; pigmented or textured grades preferred over polishing, and coatings are spark-tested for pinholes.
Can ECTFE GF25 be formed, bent or molded?
Injection mould/extrude at 260–310 °C with corrosion-resistant (Hastelloy/nickel-alloy) barrels and hot runners; shrinkage 1.5–3.5 %, sheet thermoforms at 180–230 °C, powder applied electrostatically then fused at 260–290 °C.
What is the maximum service temperature of ECTFE GF25?
ECTFE GF25 is rated for continuous use to about 150°C (302 °F), and briefly to 180°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D3275 — Standard Specification for E-CTFE Fluoroplastic Molding, Extrusion, and Coating Materials — ASTM International (2019)
- Halar ECTFE Design & Processing Guide / grade data sheets — Solvay Specialty Polymers (Syensqo) (2022)
- Engineered Materials Handbook Vol.2 — Engineering Plastics (fluoropolymers) — ASM International (1988)
- CAMPUS / UL Prospector fluoropolymer property records — CWFG / UL Solutions (2024)
- Fluoroplastics, Volume 2: Melt Processible Fluoropolymers — Elsevier (Plastics Design Library) (2015)
- ECTFE/ETFE (2026)
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.