TFM / PPVE-Modified PTFE
Modified PTFE: Low Creep
Modified PTFE (commonly sold as TFM or Teflon NXT) is virgin PTFE copolymerised with less than 1% PPVE. This trace co-monomer inhibits crystallisation during sintering, producing a denser material with approximately 60–75% less deformation under load (ASTM D621) than typical virgin PTFE, while retaining near-identical chemical inertness across the same -200 °C to +260 °C service range. We stock modified PTFE sheet for high bolt-load flanged joints, critical chemical seals, and pharmaceutical applications where virgin PTFE creeps but filled PTFE compromises chemical resistance.
At a Glance
Temperature Range
-200 °C to +260 °C continuous
Thickness Range
0.5 mm to 6 mm (thicker billets available for machining)
Hardness Range
57–69 Shore D
Available Forms
Colours
Brands We Stock
Technical Properties
Typical values across stocked grades. Specific grade data sheets available on request.
Physical Characteristics
Density
2.14–2.17 g/cm³ (ASTM D792)
Tensile Strength
28–33 MPa (ASTM D4894)
Elongation at Break
300–580% (ASTM D4894)
Thermal Conductivity
0.22 W/(m·K) (ASTM D1530)
Chemical Resistance
Resistant To
- Mineral acids at most concentrations — H₂SO₄, HCl, HNO₃, HF (see notRecommended for oleum and hot concentrated HNO₃)
- All concentrations of alkalis (NaOH, KOH)
- Organic solvents (acetone, MEK, toluene, xylene, chloroform)
- Fuels and petroleum products
- Chlorine and bromine (gaseous, at moderate pressure)
- Hydrogen peroxide up to 30% at ambient temperature
- Sodium hypochlorite up to ~12.5%
- Water, steam, and brine
- Pharmaceutical and food-grade media
Limited Resistance
- Concentrated hydrogen peroxide above 30% — verify case-by-case
- Hot concentrated nitric acid above ~70% — limit exposure
- Molten or dissolved alkali metals at high temperature
Not Recommended
- Oleum (fuming sulphuric acid)
- Molten alkali metals (sodium, potassium, lithium) — decompose the fluorocarbon chain
- Elemental fluorine at high pressure and temperature
- Interhalogen fluorinators (ClF₃, BrF₃, OF₂) at any concentration — violent reaction risk; relevant for semiconductor fluid handling
- Ionising radiation (gamma rays, high-intensity X-rays), which causes polymer degradation
Environmental Ratings
Flame Rating
Non-flammable. PTFE does not sustain combustion (LOI >95%)
Weather Resistance
Excellent; inherently UV, ozone, and weather resistant
Ozone Resistance
Excellent (fully inert)
UV Resistance
Excellent. No degradation from UV exposure
Standards & Certifications
Standards Compliance
Common Applications
- High bolt-load flanged joints where virgin PTFE cold-flows
- Chemical processing seals requiring both creep resistance and universal chemical inertness
- Pharmaceutical and bioprocess seals (USP Class VI grades)
- Food and beverage processing gaskets (FDA grades)
- Semiconductor and high-purity fluid handling
- Welded PTFE linings and fabricated vessels (weldable unlike virgin PTFE)
- Gas-tight seals where lower permeation than virgin PTFE is required
- Valve and pump seals in aggressive chemical service
- Cryogenic service requiring dimensional stability under load
- Laboratory and analytical equipment seals
Not Recommended For
- Higher cost than virgin PTFE, since the PPVE co-monomer and controlled sintering add manufacturing expense
- Still softer than filled PTFE grades. Where maximum creep resistance is needed under extreme loads, glass or carbon filled PTFE may be more appropriate
- Not radiation-resistant — gamma and high-intensity X-ray exposure causes polymer chain degradation
- Limited availability in very thick sections compared to virgin PTFE billets
- Actual FDA/USP compliance is grade- and lot-specific. Confirm with supplier for each order
Available Grades
Brands we stock: Dyneon (3M), Chemours, Enflon, Fluorolon
TFM (3M/Dyneon)
Food SafeThe original and most widely referenced modified PTFE resin family. TFM 1700 is the standard powder grade for compression moulding and ram extrusion. Tensile strength 33 MPa, elongation 450%, deformation under load 4.0% at 15 MPa.
Teflon NXT (Chemours)
Food SafeChemours' modified PTFE resin range (NXT-70, NXT-75, NXT-85). Fine-cut and pelletised grades for various processing methods. Deformation under load as low as 0.2% at 3.4 MPa. Successor to the earlier Teflon 807NX.
Modified PTFE Sheet (Fabricator Grades)
Sheet stock moulded and skived by specialist fabricators from TFM or NXT resins. Available as standard sheet thicknesses for gasket cutting, or as custom-machined components.
Related Resources
Virgin PTFE Sheet
Compare with standard virgin PTFE: lower cost but significantly more creep under load.
Filled PTFE Sheet
Compare with glass, carbon, and bronze filled PTFE — better creep resistance but reduced chemical compatibility.
Chemical Compatibility
Check PTFE compatibility with your process media.
Gasket Selection Guide
Find the right gasket type for your application.
Related Materials
Need Modified PTFE: Low Creep?
We supply modified ptfe: low creep in sheet, roll, and custom die-cut forms. Contact our team for pricing, data sheets, or technical assistance.
Disclaimer
This resource is provided for general engineering reference only and does not constitute professional advice, specification, or guarantee of performance. Actual results depend on specific application conditions. Universal Gaskets Pty Ltd accepts no responsibility or liability for decisions made based on this information. For full terms, see our Terms & Conditions.