Understanding the role of PTFE seals in modern engineering

PTFE (Polytetrafluoroethylene) seals are high performance components used in demanding environments where traditional rubber or elastomer seals cannot withstand extreme conditions. Known for their outstanding resistance to chemicals, high temperatures, and friction, PTFE seals ensure long-lasting reliability in both static and dynamic applications.
At Ashton Seals, we supply PTFE products designed for optimal sealing integrity across a range of industries including chemical processing, automotive, and food manufacturing.

What is PTFE?

PTFE, commonly known by the trade name Teflon, is a fluoropolymer with unique non-stick and non-reactive properties. It is chemically inert, highly stable, and resistant to a wide variety of fluids and gases. These characteristics make it an ideal material for seals operating in chemically aggressive or high-temperature environments.

Key properties of PTFE:

• Excellent resistance to nearly all industrial chemicals and solvents.
• Operates effectively across a wide temperature range (-200°C to +260°C).
• Low coefficient of friction for smooth operation.
• Non-stick surface resists contamination.
• Exceptional dimensional stability and wear resistance when filled or reinforced.

How PTFE seals work?

PTFE seals function by creating a tight, reliable barrier between two surfaces. When compressed, the PTFE material conforms to surface irregularities, ensuring a leak-free seal even under high pressure or fluctuating thermal conditions.

How they seal:

• The PTFE ring or lip is compressed against a mating surface to form a barrier.
• The material’s low friction allows dynamic motion without excessive wear.
• PTFE’s inertness prevents chemical degradation or swelling over time.
• Reinforced or filled PTFE grades improve sealing performance under pressure and movement.

This makes PTFE seals ideal for rotating shafts, valve stems, hydraulic cylinders, and mechanical assemblies operating under extreme conditions.

Common applications of PTFE seals

PTFE seals are used wherever reliability, chemical resistance, and temperature stability are essential. Typical uses include:

• Chemical processing equipment – providing long-term sealing in aggressive chemical media.
• Automotive systems – offering low-friction sealing for rotary shafts and engine components.
• Food and pharmaceutical machinery – ensuring hygienic and non-contaminating sealing solutions.
• Hydraulic and pneumatic systems – maintaining sealing integrity in high-pressure operations.
• Aerospace and energy sectors – performing reliably in fluctuating temperature and pressure conditions.

PTFE’s versatility makes it suitable for static, dynamic, and rotary sealing applications where other materials might fail.

Types of PTFE seal designs

PTFE sealing technology covers a variety of profiles, each suited to specific operating conditions:

• Lip seals: Designed for rotary motion with low friction and high wear resistance.
• Spring-energised seals: Incorporate a metal spring to maintain consistent pressure and compensate for material creep.
• Back-up rings: Used alongside O-rings to prevent extrusion under high pressure.
• Encapsulated seals: Combine PTFE with elastomer cores for enhanced elasticity and sealing performance.

Selecting the right PTFE seal design depends on operating pressure, temperature, motion type, and media compatibility.

Advantages of PTFE seals

PTFE seals provide a combination of mechanical and chemical performance unmatched by most sealing materials

Key advantages:

• Exceptional chemical inertness and resistance to corrosion.
• Wide operating temperature range from cryogenic to high-heat applications.
• Excellent wear and abrasion resistance for extended lifespan.
• Low friction for smooth, energy-efficient operation.
• Non-stick properties reduce build-up and simplify maintenance.

These advantages make PTFE seals a trusted solution across high-performance industries requiring reliability under stress.

Limitations of PTFE

While PTFE is extremely durable, it does have certain limitations compared to elastomeric materials:

• Low elasticity: It does not stretch or recover like rubber, requiring precise groove design.
• Creep tendency: Under sustained pressure, PTFE may slowly deform (known as cold flow).
• High wear rate when unfilled: Reinforced PTFE compounds are often used to improve wear resistance.

Understanding these factors helps engineers design systems that maximise PTFE’s strengths while minimising its weaknesses.

Why choose Ashton Seals?

Ashton Seals brings decades of experience in supplying precision-engineered sealing solutions for industrial and technical applications. Our PTFE gaskets & Sigma PTFE materials are designed and tested to perform in the most demanding conditions.

Our advantages:

• Extensive material selection including filled and unfilled PTFE grades.
• Technical support for correct material and seal selection.
• Reliable supply chain and consistent product quality.
• Expertise across diverse sectors from manufacturing to chemical processing.​

Whether you require static, dynamic, or rotary sealing, Ashton Seals delivers performance, precision, and reliability.

FAQs

 

1. What is a PTFE seal?

A PTFE seal is a mechanical sealing component made from polytetrafluoroethylene, designed to resist chemicals, extreme temperatures, and friction. It is used in applications where elastomeric seals would degrade or fail.

2. What are the advantages of PTFE over rubber seals?

PTFE seals offer superior chemical resistance, lower friction, and wider temperature tolerance compared to rubber seals, making them ideal for demanding industrial environments.

3. Can PTFE seals handle high pressure?

Yes. PTFE seals can withstand high-pressure conditions, especially when reinforced or used with spring energisers or back-up rings to prevent extrusion.

4. What industries use PTFE seals the most?

PTFE seals are widely used in automotive, chemical, pharmaceutical, energy, and food manufacturing industries for both static and dynamic applications.