What is a PTFE-coated gasket?

​1. What is a PTFE-coated gasket?

A PTFE-coated gasket is a composite sealing gasket. It cleverly combines the advantages of an "elastic inner core" and a "PTFE coating layer."[2-3]

In the harsh working conditions of the petroleum, chemical, pharmaceutical, and food industries, it is crucial to find a gasket that can withstand highly corrosive media while maintaining long-term sealing performance. PTFE-coated gaskets, also known as polytetrafluoroethylene-coated gaskets, are the ideal solution to this problem.

Structural Composition:

* Inner Core (Support Layer): Typically made of elastic materials such as asbestos rubber sheets, asbestos-free sheets, rubber, or graphite-reinforced sheets. It provides the gasket with structural strength and resilience.

* Outer Layer (Coating Layer): Encased in a polytetrafluoroethylene (PTFE) film. This layer directly contacts the medium, giving the gasket excellent corrosion resistance and non-stick properties.

This "rigid-flexible" design allows the gasket to possess both the elasticity of rubber and the chemical resistance of PTFE.

2. Three Types of PTFE-Coated Gaskets

Depending on different operating conditions, PTFE-coated gaskets are mainly divided into the following three structural types:

V-type (Sliced): Suitable for low-pressure conditions, economical and practical. Typically used for pipe flanges from DN15 to DN200mm.

L-type (Machine-Made): Machined from PTFE sheet, suitable for medium and high-pressure environments, offering more stable sealing performance.

U-type (Folded-Insert): Formed by heating and bonding PTFE tape around the edges, particularly suitable for sealing large-diameter flanges larger than DN200mm.

3. Overview of Core Performance Parameters

Understanding the limiting parameters of sealing components is a prerequisite for safe operation when selecting them. The following are the standard performance specifications for PTFE-coated gaskets:

Parameter Item Typical Value/Range Remarks of our SUNPASS products:

4. Why choose PTFE-coated gaskets?

Excellent Corrosion Resistance PTFE is known as the "King of Plastics" .

Many peculiar properties such as high thermal conductivity in composite form, mechanical strength, hydrophobicity, and chemical inertness have been manifested by PTFE. The average melting point of PTFE is 325to 335 °C hence PTFE has been classified among thermoplastics because of the high thermal resistance and high operating temperature. Due to its physical and chemical properties, PTFE has been considered as a functional polymeric material in industrial domains. It has been preferred as a nonstick coating material to withstand high-temperature cycles. [1]

② Excellent Non-stick and Self-Lubricating Properties PTFE has the lowest known surface energy of any solid material, making it difficult for almost any substance to adhere to it. This characteristic not only facilitates cleaning and prevents media residue, but also gives it an extremely low coefficient of friction, making installation smoother.

③ Wide Temperature Range Adaptability: From extremely cold temperatures of -180℃ to high temperatures of +260℃, PTFE-coated gaskets maintain stable physical properties, without becoming brittle or melting, meeting the needs of extreme temperature conditions.

④ High Safety and Cleanliness: Due to its chemical inertness, PTFE gaskets will not contaminate the media they come into contact with. This makes them irreplaceable in the food and pharmaceutical industries, meeting sanitary sealing requirements.

5. Main Application Areas

Chemical Industry: Sealing of reactors, heat exchangers, valves, and pipelines, especially in systems handling chlorine, strong acids, and strong alkalis.

New Energy Materials: Sealing of corrosive chemical media in lithium battery electrolyte and precursor production.

Pharmaceuticals and Food: High-purity chemical equipment and solvent recovery systems, ensuring products are not contaminated.At present, PTFE is an inevitable material for food processing varying from small domestic applications (non-stick cookware surface coating) to mass production of food in factories (conveyor belts, gaskets, and packaging). The inertness and low surface energy of PTFE restrict the adherence of other molecules over its surface hence PTFE is the best known polymer used for hygienic and non-hazardous processing conditions. Applications of PTFE in food processing lead in the way to reduce fouling, food contamination, and biofilm formation.[1]

6.SUNPASS Product Recommended

WHY US?

Prior to on-site entry, suppliers are required to provide complete material certificates. We use only virgin PTFE resin from international brands such as DuPont, Daikin, and 3M. The PTFE is food-grade and 100% asbestos-free,FDA Certified, and we conduct random batch testing.EPDM is from from international brands too.

During production, we utilize advanced CNC equipment and standardized operating procedures.

Quality control points are established at every critical process stage; operators are required to record data in real time and sign off on it.

We provide third-party test reports, facilitate factory audits, and conduct comparative sample testing.

Our PTFE products feature a wider width than comparable products on the market and are made of high-quality materials that prevent leaks and media contamination. They are the mandatory and optimal choice for high-purity industries such as food and pharmaceuticals, effectively reducing the likelihood of poor sealing performance caused by improper installation.

Comprehensive pres-ales and after-sales service guarantees:

• One-year warranty;
• Ample stock of standard sizes for prompt shipment;
• Fast-track service for urgent orders;
• Free product selection and technical consultation;
• Free small-batch samples.

As a a high-quality supplier to a globally industrial sealing and thermal insulation materials manufacturing company, we also offer other gasket,please contact us if you are interested.

Reference

Dhanumalayan, E., and Girish M. Joshi. "Performance properties and applications of polytetrafluoroethylene (PTFE)—a review." Advanced Composites and Hybrid Materials 1.2 (2018): 247-268.

2. Guan Ping, Jiang Jiatong. PTFE-coated rubber gasket: CN, CN202660116U[P]. 2013.

3.Chen Ruyao. Treatment of Polytetrafluoroethylene Film Using the Sodium Naphthalate Method [J]. Rubber Industry, 2000, 47(5):317-317.

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