ETFE GF25
Reinforced grade
ASTM D3159 · ISO 12086 · also Tefzel
GF25 = 25% glass-fiber reinforced
Pick when stiffness, creep resistance and dimensional stability at 150–200 °C are needed — valves, pump parts, structural chemical hardware.
Values for the GF25 condition
What is ETFE GF25?
ETFE GF25 is ETFE in the GF25 grade — pick when stiffness, creep resistance and dimensional stability at 150–200 °C are needed — valves, pump parts, structural chemical hardware. ETFE GF25 has a yield strength of 22 MPa (3.19 ksi) and a tensile strength of 82 MPa (11.9 ksi) — weaker than 78% of polymer grades. Elongation at break is 8% and the elastic modulus is 6 GPa (0.87 Msi). ETFE GF25 has a density of 1.89 g/cm³ (0.0683 lb/in³), heavier than 97% of polymer grades. Its glass-transition temperature is 105°C (221 °F).
Advantages
- Good UV / weathering resistance — 98/100, better than 99% of polymer grades
- Stiff — 6 GPa (0.87 Msi), better than 89% of polymer grades
- Low moisture uptake — 0.03%, better than 89% of polymer grades
- Readily welded — 80/100, better than 86% of polymer grades
- High service temperature — 180°C (356 °F), better than 85% of polymer grades
Limitations
- Heavy — 1.89 g/cm³ (0.0683 lb/in³), worse than 97% of polymer grades
- High embodied carbon — 14 kg CO₂/kg, worse than 95% of polymer grades
- Low strength — 22 MPa (3.19 ksi), worse than 78% of polymer grades
ETFE GF25 properties
Typical room-temperature values for ETFE GF25; 14 are specific to this condition. Other listed values are ETFE reference data and may not represent this condition. Bars are the position among polymer grades.
Physical7
ETFE GF25 has a density of 1.89 g/cm³ (0.0683 lb/in³), heavier than 97% of polymer grades. Its glass-transition temperature is 105°C (221 °F).
Mechanical10
ETFE GF25 has a yield strength of 22 MPa (3.19 ksi) and a tensile strength of 82 MPa (11.9 ksi) — weaker than 78% of polymer grades. Elongation at break is 8% and the elastic modulus is 6 GPa (0.87 Msi).
Thermal11
ETFE GF25 is rated for continuous service to 180°C (356 °F). It conducts heat at 0.24 W/m·K (0.139 BTU/hr·ft·°F), better than 67% of polymer grades. Thermal expansion is 28 µm/m·K (15.6 µin/in·°F).
Electrical7
ETFE GF25 is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of ETFE GF25 takes about 230 MJ of energy and emits 14 kg of CO₂ — more than 91% of polymer grades. Typical recycled content is 0%.
Manufacturability8
ETFE 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 ETFE GF25
Is ETFE easy to machine?
Machines like a tough soft plastic — sharp positive-rake carbide tools, high speed, low feed and good chip clearance; parts creep-relax, so allow generous tolerances and stress-relieve near 150 °C before finish cuts.
Can ETFE be welded?
Readily hot-gas, heat-impulse, hot-plate and extrusion welded with ETFE filler at 320–360 °C; film seams are heat-sealed and reach near-parent-material strength, but always use fume extraction (HF risk above ~350 °C).
Can ETFE be formed, bent or molded?
Melt-processable by injection, extrusion, rotolining and film casting at 300–340 °C using corrosion-resistant (Hastelloy/nickel-alloy) screws and dies; shrinkage is high (2.5–4.5%) and moisture-free feed plus purge-out at shutdown are essential.
What surface finishes work on ETFE?
Low surface energy means no paint, adhesive or print will stick without sodium-etch, plasma or corona treatment; the surface is self-cleaning and needs no coating for outdoor service.
ETFE 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 |
|---|---|---|
| tetrafluoroethylene (TFE) units≈1:1 mole ratio with ethylene; wt% basis | 72 – 82 | 78 |
| termonomer (PFBE / HFP / PFPVE)bulky side-chain modifier added to suppress high-temperature stress cracking | 0.5 – 5 | 1.5 |
| glass fiberreinforced grades only (GF25) | ≈ 25 | 25 |
| ethylene unitsalternating copolymer backbone | ≥ 18 (balance) | — |
ETFE GF25 — frequently asked
What is ETFE GF25 used for?
ETFE GF25 is typically used for aerospace/mil wire insulation, architectural roofing film, chemical process tubing and solar panel backsheets. In short: toughest melt-processable fluoropolymer; architectural film grade; radiation-resistant wire insulation.
What is the yield strength of ETFE GF25?
ETFE GF25 has a typical yield strength of 22 MPa (3.19 ksi) and a tensile strength of 82 MPa (11.9 ksi) — weaker than 78% of polymer grades.
Is ETFE GF25 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 73% of polymer grades). Machines like a tough soft plastic — sharp positive-rake carbide tools, high speed, low feed and good chip clearance; parts creep-relax, so allow generous tolerances and stress-relieve near 150 °C before finish cuts.
Can ETFE GF25 be welded?
Yes — weldability is rated very good (80/100). Readily hot-gas, heat-impulse, hot-plate and extrusion welded with ETFE filler at 320–360 °C; film seams are heat-sealed and reach near-parent-material strength, but always use fume extraction (HF risk above ~350 °C).
What surface finishes work on ETFE GF25?
Low surface energy means no paint, adhesive or print will stick without sodium-etch, plasma or corona treatment; the surface is self-cleaning and needs no coating for outdoor service.
Can ETFE GF25 be formed, bent or molded?
Melt-processable by injection, extrusion, rotolining and film casting at 300–340 °C using corrosion-resistant (Hastelloy/nickel-alloy) screws and dies; shrinkage is high (2.5–4.5%) and moisture-free feed plus purge-out at shutdown are essential.
What is the maximum service temperature of ETFE GF25?
ETFE GF25 is rated for continuous use to about 180°C (356 °F), and briefly to 200°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D3159 — Modified ETFE Fluoropolymer Molding and Extrusion Materials — ASTM International (2021)
- ISO 12086 — Plastics: Fluoropolymer dispersions and moulding/extrusion materials — ISO (2006)
- Tefzel ETFE fluoropolymer resins — properties handbook — DuPont / Chemours (2019)
- Neoflon ETFE product and processing guide — Daikin (2020)
- Nowoflon ET / ETFE film technical data — Nowofol (2021)
- Fluoroplastics, Vol. 2: Melt Processible Fluoropolymers — Ebnesajjad / Elsevier (2015)
- CAMPUS / UL Prospector ETFE datasheets — CWFG / UL (2023)
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.