PTFE

PTFE – Premium Sealing Material for Challenging Environments

Poly­tetrafluoroethylene (PTFE) is one of the most chemically inert, durable and temperature‑tolerant materials available today — making it an outstanding choice for O‑rings, seals and components in demanding chemical, industrial, or extreme temperature applications.

Why PTFE is Special

• Unmatched chemical resistance. PTFE is chemically inert to almost every substance — including strong acids, bases, oils, solvents, steam and many aggressive chemicals used in industry.
• Wide operating temperature range. PTFE remains stable and retains performance in extreme conditions: continuously usable from deep‑cryogenic lows (down to around –200 °C) up to high temperatures near 260 °C. Short‑term exposure to its melting range (~327 °C) is also possible.
• Very low friction & non-stick behaviour. PTFE has one of the lowest coefficients of friction among solid materials — it’s often described as “sliding like wet ice on wet ice.”
• Excellent electrical and thermal insulation. Its stable dielectric properties and low thermal conductivity make it suitable for electrical insulation and thermal‑insulation applications in demanding environments.
• Durability, toughness and weather resistance. PTFE retains strength and toughness across broad temperature ranges. It resists UV, ozone, moisture absorption (near zero water uptake), and long‑term chemical attack — offering impressive longevity in harsh conditions.

Typical PTFE Properties (Virgin / Unfilled)

Common Uses & Applications for PTFE Seals & Components

Given its unique combination of properties, PTFE is often selected where fewer materials can meet the technical demands:

• Chemical processing / aggressive media: seals, O‑rings, gaskets, linings, pipework in applications handling acids, bases, solvents — where chemical inertness and corrosion resistance are critical.
• High- and low-temperature environments: equipment and systems exposed to cryogenic lows or high thermal stress (e.g. valves, pumps, compressors, pressure equipment, steam systems).
• Dynamic seals and moving systems: thanks to low friction and wear — bearings, bushings, sliding components, valve stems, shafts, mass spectrometer probes, rotary equipment. (Especially beneficial where lubricants are undesirable or incompatible.)
• Food, pharmaceutical and clean applications: where chemical inertness, non-stick / non-contaminating surfaces, and compliance with hygiene / safety regulations (e.g. FDA food-contact compatibility) are required.
• Electrical / thermal insulation: parts or components requiring stable insulation across temperature ranges or resistance to chemical exposure (e.g. cable insulation, high‑voltage applications, sensors, cryogenic instrumentation).
• Outdoor / weathered / UV-exposed environments: systems where long-term exposure to UV, moisture or ozone could degrade lesser materials — PTFE remains stable.

Strengths — and What to Consider

Strengths

• High chemical and corrosion resistance — resistant to nearly all acids, bases, solvents, oils, steam and aggressive chemicals.
• Broad temperature tolerance (from cryogenic to high heat).
• Extremely low friction coefficient and non-stick surface — ideal for dynamic or sliding applications.
• Excellent dielectric and thermal insulation properties.
• Stable under UV, ozone, moisture, and harsh environments — good long-term weather and ageing resistance.
• Versatile in forms: pure resin, filled compounds, rods, tubing, specialty profiles, moulded components.

Considerations

• Poor elastic memory / limited elasticity: Unlike elastomers (rubbers), pure PTFE lacks true “rubber‑like” elasticity — this can make O‑ring installation and sealing more challenging, especially without filler or design adjustments.
• Cold‑flow (creep) over time under compression: In static seal or gasket applications, PTFE may gradually deform under sustained load. For critical sealing, using compounded PTFE (with fillers) is often recommended.
• Lower mechanical strength vs. metals or high‑performance plastics: While PTFE is tough and low-friction and wear-reducing, tensile strength and rigidity are lower than many engineering plastics — for load-bearing or high‑stress mechanical components, filled or reinforced PTFE grades are usually preferred.
• Processing limitations: Virgin PTFE cannot be easily processed using standard melt‑processing methods (e.g. injection moulding) due to its flow behaviour. Specialized processing — compression moulding, sintering, paste or ram extrusion — is required.

Why Choose PTFE from Us (or What PTFE Offers in Our Sealing Range)

We select PTFE as a core material for sealing solutions precisely because of its unmatched combination of chemical, thermal, and physical properties. When you rely on PTFE seals, O‑rings, or gaskets from our range, you benefit from:

• High reliability in aggressive chemical and high-temperature environments — suitable for chemical processing, oil & gas, steam, solvents, acids/alkalis, and more.
• Flexible sealing solutions across extreme temperatures — from deep cryogenic to high-heat applications.
• Low‑friction, wear‑resistant, long‑lasting seals for moving parts — ideal for valves, actuators, rotating shafts, sliding surfaces.
• Compliance with hygiene, food-contact or pharmaceutical standards (in appropriate PTFE grades) — offering safety and chemical inertness where contamination must be avoided.
• Customisable material forms — from standard O‑rings to custom mouldings, rods, tubing, or specialised profiles — depending on your application requirements.

Summary: When PTFE Is the Right Choice

Choose PTFE when you need a sealing or component material that must withstand:

• harsh or corrosive chemicals,
• a very broad temperature range (from cryogenic to high temperatures),
• dynamic or sliding contact with minimal friction,
• long-term resistance to UV, moisture, ozone or aggressive environments,
• chemical inertness and non‑contamination (e.g. food, pharma),
• and/or stable electrical or thermal insulation under challenging conditions.

However, if your application demands rubber‑like elasticity, high compression sealing with minimal creep, or structural rigidity under heavy load, consider using filled/reinforced PTFE or alternative elastomeric/sealing materials.

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PTFE is hampered by very poor elastic memory at room, or low temperatures. This presents problems in O-ring installation, and requires extra care to be taken in control over O-ring I.D.

Because of its poor tear resistance, during O-ring installation particular care should be taken to avoid nicking or scratching, as imperfections will cause O-ring leakage. However the material is not easily compressed, and therefore may not seal as easily as some of the other polymers. Finally, the tendency of PTFE to cold flow over time, when used in gasket type applications, may require special material compounding (with fillers) to control such “creep” in critical sealing situations.

Please note: This Material Data Sheet section is to be used as a professional guide only. Eastern Seals (UK) Ltd may source their products from a variety of Quality Approved Suppliers and the data shown should not be relied upon by any purchaser without verification of material source.

ES REF	Colour	Temp Range	Hardness	Notes	Data Sheet
PTFE	WHITE	-100⁰C to +250⁰C	–	A Conductive PTFE compound 1% by weight composition of Carbon Black. 99% free flowing granular PTFE, for auto Isostatic and general purpose compression moulding. Material meets the FDA regulation under code 21CFR 177.1550 and Euro Directive 10/2011/EC for material that may come into contact with food.	PTFE