PTFE Vs. PEEK: Engineering Plastic Friction Comparison

When it comes to drilling and removal of the drilling, the materials are always the most prized ones and perform the best in the intense conditions that would be equivalent. PTFE or Poly tetra fluro ethylene and PEEK or poly ether ether ketone are just a few to mention of the high performance plastics, and are popular due to their unique properties, which they portray. A further contrasting point between these two materials is their behavior in contact situations, which is very important to the components’ effectiveness, durability, and reliability. This blog post addresses such a topic and affords an in-depth comparison of PTFE and PEEK by their most notable feature in detail, disadvantages, and where they are best used. No doubt, if you are an engineer or designer or are just interested in the newest construction materials, you will find this discussion very effective in helping you make an informed decision regarding what plastic to use.

Understanding PTFE and PEEK

There are two high-performance thermoplastics, namely PTFE and PEEK. It most especially comes in a simple shape and is made up of spiro, ethene, and all those halogen electrons that are both very acidic and very small. PTFE is well known for its specific functionality that prevents adhesion and extreme resistance to sliding, but also for its ability not to be reactive to most reagents. It does not surprise many that it is used as a polymeric film for coating, sealing, and lining since this low surface energy material has an exceptionally low friction coefficient. In contrast, PEEK is an abundant material with moderate chemical stability, exceptional mechanical stability, high corrosion resistance, thermal stability, particularly metallurgical stability at high temperatures, and friction resistance, and is thus well suited for space missions and biomedical applications. The decision to use PTFE or PEEK involves others based on factors such as temperature, mechanical strain, and contact with chemical or other reagents.

What is PTFE?

PTFE (Polytetrafluoroethylene) is a polymer that was made by polymerizing tetrafluoroethylene. Polytetrafluoroethylene, also called Teflon, is an outstanding material because it offers many features that can be applied commercially in several industries. PTFE shields it from most chemicals as it is not a reactive material due to its structure. With low friction, it resists and has a certain surface to be used in utensils and developing non-stick cookware. This is mainly because PTFE can also function when exposed to high heat, and its qualities remain the same even if the temperature goes up or down. In manufacturing, PTFE is employed in electrical insulation products, troubleshooting gaskets, and manufacturing implants or other medical equipment. Though it was produced in 1938 by the American chemicals and manufacturing company DuPont, PTFE has become one of the most popular hydraulic products, available under several brand names, including Teflon.

What is PEEK?

Polyether ether ketone (PEEK) is an advanced plastic due to its mechanical, chemical, and physical properties. It also tolerates high temperatures, rubbing, and some solvents and therefore finds application in demanding conditions. This material has many industrial uses, including replacing metal in parts that do not require much structural strength, like in the aerospace, automobile, and medical sectors. It has a lightweight yet robust design and remains constant in harsh environmental conditions. Finally, it has good electrical characteristics and can be sterilized, increasing its usability even in various sanitary applications. This material has a particular application in the market in replacing some parts in high-temperature environments, which is why it’s replacing metal.

Key Properties of PTFE and PEEK

• PTFE (Polytetrafluoroethylene):

PTFE is commonly used because it is highly resistant to almost all chemicals, making it perfect for chemical conditions such as gaskets and acidic seals. It is resistant to various chemicals, such as acids, bases, and solvents, and can survive even exposure to corrosive chemicals.

Very Good Heat. PTFE can be used within the temperature range 328°F to 500°F (-200°C to 260°C) without thermal damage.

Low Friction: In dry solid-state, PTFE is known for its incredibly low coefficient of friction, which increases service life and performance in applications where materials rub against each other.

Non-wetting Properties: The material’s water repellent character indicates that it does not stick easily to the surface, thus enabling it to be used mainly in various industrial coatings and food-grade applications.

Outstanding Electrical Insulation Riders: PTFE exhibits remarkable electrical insulating properties, excluding electrical losses. It is an excellent insulator and is commonly employed in electronics and cables to ensure maximum capacitance.

• PEEK (Polyetheretherketone)

Excellent Tensile properties: PEEK has a high tensile strength, with an average tensile modulus of 3.6 GPa. Hence, the material retains its stiffness under substantial mechanical loads.

Heat stability: PEEK can be used in high-temperature conditions without losing chemical stability to thermal breakdown, with a maximum usage of 482°F (250°238). The melting point is around 662°F (343°C).

Chemical resistance: PEEK is suitable for application under harsh chemical conditions and covers a wide range of liquid and gas chemicals, such as hydrocarbons, acids, and bases.

Resistance to the effects of wearing and tearing includes maximum acceptance of torsion transmission and exposure to aggressive working environments, resulting in wear and tear, such as in bearings and piston parts.

Safety and Decomposition: PEEK is sterile in medical Marwan’s implants and medical equipment because its official biologically harmless PEEK is not dangerous to park on the other side.

Comparative Analysis of PTFE and PEEK

1. Both PTFE and PEEK are highly polymerized; however, some distinctions can be made concerning the following:
2. Heat Resistance: PTFE performs well at high temperatures, but its strength reduction is greater than that of PEEK in thermal exposure due to its good balance of strength vs. temperature.
3. Chemical Resistance: The two materials are very resistant to chemical attack; however, while PTFE can be considered non-reactive in most cases, PEEK can fend off some but not all.
4. Strength of Materials: PEEK’s heat deflection and strength of materials are much better than those of PTFE, making this material more suitable for structures where high loads need to be supported and prevented from deforming.
5. Frictional and Wear Properties: While PTFE has a very low friction coefficient, enabling it to be used in cases where lubrication and wear resistance are key, PEEK offers the same purpose but withstanding more loading.
6. Usage: PTFE’s elastic and frictional properties make it applicable in devices and things that need a nonsticking, gripping, or sealing surface. In contrast, PEEK, which has limited applications in the health, aerospace, and engineering fields due to its enhanced toughness and inherent risks, is more widely used in these fields.

Each of these materials brings a unique strength. The right polymer investment in an application between PTFE and PEEK will be based on the said conditions and implications of the given requirements.

Friction Characteristics

Bearing is an influential variable in examining the properties of PTFE and PEEK compared to each other, as it significantly affects their behavior in operational fulfillment. PTFE stands out for its exceptionally low friction levels, typically rendering a friction range between 0.04 and 0.10, making this material one of the ‘slipperiest’ available.

This attribute is why PTFE is popularly applied in non-stick coatings, bearings, and sliding-related elements to minimize wear and energy loss. Moreover, the fact that this capacity does not cease to operate efficiently under altered temperature and pressure conditions enhances its perfection.

On the other hand, PEEK has a comparatively lower frictional resistance and is characteristically described as being dry, offering a value of 0.20 to 0.30 depending on the smoothness of the surface and the working environment. However, PEEK’s coefficient of friction, although less than PTFE, is compensated by a rise in wear resistance and mechanical properties of the material. Such a strength allows PEEK to be utilized under higher loads and more severe operating conditions without reducing its lifetime. Materials and parts such as bearings, suppression rings, or even alloy system clutches can also be used where strength and satisfactory sliding properties are paramount.

Even the advances in surface finishing and development of various composite materials have witnessed the customisation of PTFE and PEEK to overcome specific frictional problems faced in aerospace, automotive, and medical industries. To better illustrate, wear characteristics of PTFE can be improved, for instance, by adding graphite or glass fibres that increase the wear resistance while achieving no increase in friction. As for PEEK, it is possible to incorporate carbon or glass reinforcing fibres to address the problem of poor load support and high friction.

Mechanical Properties

PTFE and PEEK have some unusual features, at least enough to make them suitable for several applications. Here is an in-depth analysis of their mechanical features:

PTFE

1. Tensile Strength: PTFE’s tensile strength is usually about 2500 to 4500 psi (17 to 31 MPa), which makes it ideal for applications like elastomers, which are resistant to deformation and durable.
2. Hardness: PTFE is relatively soft but elastic and scores between 50 and 65 on the Shore D scale.
3. Friction Coefficient: PTFE is a high-performance engineering plastic with a coefficient of friction as low as 0.04, which is hard to get elsewhere. Hence, its use is intended to avoid wear.
4. Temperature Resistance: PTFE is stable over a wide range of atmospheric and process temperatures, from -185°C to 260°C (-328°F to 500°F).
5. Elongation: Typically, this material enjoys elongation at break higher than 200%, which is 300-500% in the case of PTFE. It can be considered adequate as it shall withstand any deformation without breaking.
6. Density: This project’s density is around 2.2 g/cm3, making it a lightweight but strong material.

PEEK

1. Tensile Strength: PEEK is known for its astonishingly high tensile strength of 14000 to 20000 psi ( 96-138 MPa), which has led to it being termed the polymer capable of carrying heavy loads and high stress conditions.
2. Hardness: PEEK ranks at approximately 85 on the Shore scale and is, therefore, very tough, yielding much less deformation and wear.
3. Friction Coefficient: Compared to PTFE, PEEK has higher friction, but when impregnated with reinforcements, the coefficient of friction can be controlled to (0.10 – 0.36), which still withstands high friction forces.
4. Temperature Resistance: PEEK is more durable than many other materials. Its maximum operating temperature is 482 Degrees F, 250 Degrees C, and it continues to sustain its shape at even higher temperatures in some configurations.
5. Impact Strength: PEEK has a high tensile strength and does not carry under strain; instead, it withstands the toughest of loads without breaking
6. Density: PEEK has a slightly higher density than PTFE, at about 1.3 to 1.5 g/cm³, which shows how hard the material is.

Both materials have strong mechanical qualities that differ greatly. PTFE is highly versatile and is generally used in applications with very little friction, compared to PEEK, which has excellent resistance to high temperatures, strengths, and load-bearing characteristics, particularly when blended with reinforcing agents. That makes them crucial in various industries, including aerospace, automotive, and pharma.

Thermal Properties

When we look at the thermal properties of PTFE and PEEK, we see that the two polymers receive significant industrial attention. The one paradox of PTFE is that its melting point is one of the lowest as far as most commonly utilized thermoplastics are concerned, standing at around 327°C (621°F). Its performance, however, is acceptable and opens better performance limits of -200°C – 260°C (-328°F – 500°F). It is used in a reasonably good heat zone and does not degrade when certain chemicals are used.

In contrast, PEEK has a higher melting point as it has greater thermal attributes and appears not to melt until around 343°C (649°F). Unreinforced grades are used up to 250°C (482°F). But when these fibers are glass or carbon, then there is further improvement in the thermal properties of PEEK and it can resist upto 315°C (599°F) over long periods of use in some situations. It also has a higher glass transition temperature of 143°C (289°F), making its application highly preferred in harsh thermal and mechanical conditions. In other words, PES can endure a higher glass transition temperature of 114°C for higher loads and sustained temperatures of -50 to 150°C.

Such distinctive properties heighten the better use of PTFE in applications requiring minimal internal resistance, as it can deliver wetness at room temperature (moisture retentive environment), and things are allowed to change to a different form. PEEK is also designed to perform well in heated environments, especially aerospace and other vehicle components. The reliability of each of these materials is excellent within their respective temperature ranges, as is the case here.

Chemical Resistance and Durability

One of the reasons PTFE and PEEK are used heavily in aggressive environments is that they exhibit extremely high levels of resistance to various forms of degradation, owing to their chemical and heat stability. This characteristic applies explicitly to PTFE as it is considered chemically inert towards most common chemical attacks that include, but are not limited to, acids, alkalis, and solvents, among many others. Conversely, PEEK might not provide for the universal resistance to chemicals as seen in PTFE. Still, it has a very high serviceability threshold when used at high pressure or in the presence of hydrocarbons, mineral oils, and oxidizing media. Likewise, using PEEK in aggressive or high-stress conditions is acceptable since the polymer is strong and thus does not shatter when used in the stressed conditions. These properties make these two materials very practical, especially for industrial or field-specific use.

Chemical Resistance of PTFE

Polytetrafluoroethylene (PTFE), commonly known by the Teflon trademark, boasts a remarkable chemical resistance profile, which makes it exceptionally well suited for applications where aggressive chemicals are employed frequently. It has proved resistant to almost all the chemical substances known to humans. It can withstand exposure to a wide range of temperatures from very low temperatures of -196°C/-320.8°F to very high temperatures of 260°C/500°F. These exceptionally resistant properties to chemical attack are due to the powerful bonds of carbon-fluorine, which are the most thermally stable in the organic field.

Detailed research and tests have revealed that PTFE does not break down even in severe conditions. For example, PTFE has an outstanding resistance to concentrated sulfuric acid, nitric acid, and hydrochloric acid even at high temperatures. Published information on the performance of plastic materials in harsh chemical environments is available in chemical databases. It clearly indicates that PTFE maintains its low, nearly degraded condition even after months of soaking in such acids to a concentration of 98%. Moreover, PTFE shows no changes upon exposure to organic solvents such as acetone, benzene, toluene, etc., and can therefore be used to handle hydrocarbons for chemical processes.

The use of PTFE is widespread in the production of drugs, foodstuffs, and electronic parts on account of its repelling contact surface. Poor PTFE’s chemical stability is responsible for low pollution or low susceptibility in any condition. The performance attainable with PTFE materials is appreciable, rendering its standing satisfactory regarding some industry standards, for use in seals, gaskets, linings, and coatings of aggressive chemical environments.

Durability of PEEK

PEEK, known as Polyether ether ketone, is known for its exceptional tensile properties. This characteristic makes PEEK a primary material in aerospace technology, medical equipment, and motor manufacturing industries. Mechanical strength PEEK is exceptionally high and may exhibit relatively negligible decrease upon exposure to elevated temperatures up to 260°C (500°F); PEEK is highly ductile, and its toughness at cryogenic temperatures, while lower than expected, is better than most engineering plastics. Perhaps most importantly, PEEK possesses extraordinary resistance to the effects of chemical corrosion, such as acids, hydrocarbons, or organic solvents, and its performance remains consistent even in highly aggressive environments.

As per academic sources and previous figures from Bulafon et al, the tensile strength of PEEK usually falls between 90 MPa and 100 MPa, while its Young’s Modulus ranges between 3.5 GPa and 4 GPa. Because of these characteristic features, PEEK is widely used in producing components that experience high stress or strain, such as gears, seals, or bearings. Also, PEEK workpieces are generally less subject to wear and suitable for creep resistance, meaning they can maintain their set dimensions over time.

The stiffness and durability of PEEK, even when subjected to sterilization procedures, such as autoclaving and gamma-irradiation, assure its usability in medicine, for example, in making parts for surgeries. The compound’s service life and the conditions in which it can be used till failure, together with resistance to heat and fatigue, allow for applications where PEEK performs better than other polymers. This is especially important in applications that demand the highest standards of safety and durability, as the case for the material is in a much broader range.

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Comparative Resistance of PTFE vs PEEK

The mechanical properties of PTFE and PEEK differ considerably in tensile strength, chemical resistance, temperature characteristics, dynamic factors, and costs, and can be employed in very different settings.

Parameter	PTFE	PEEK	Superior
Tensile Strength	25-35 MPa	90-100 MPa	PEEK
Chemical Resist.	Virtually inert	Affected by acids	PTFE
Temp. Resistance	Up to 250°C	Up to 250°C	Equal
Friction	0.03-0.05	0.35-0.45	PTFE
Cost	Moderate	Very high	PTFE
Flexural Modulus	495 MPa	3900 MPa	PEEK
Elongation	350-400%	30-40%	PTFE
Machinability	Good	Very good	PEEK

PTFE about Other Engineering Plastics

One of the most unquestioned aspects of PTFE or Polytetrafluoroethylene is its impressive chemical durability, low resistance to sliding (or friction), and non-adhesion coefficient. In this regard, PTFE is perfect since it has most of the best properties that other materials do not; it is an excellent example of giving and taking. Thanks to its good level of thermal degradation, one can utilize it for applications involving extreme environmental condition,s even more so than various commonly used traditional plastics. PTFE is low in extreme chemical environments, and its strength is a bit lower than that of materials like PEEK, which limits it to a few applications even without reinforcement. Nevertheless, the most suitable material for regard or harsh conditions is still PTFE for its chemical inertness and stability at high temperatures.

PTFE vs Other Engineering Plastics

Compared with other engineering plastics, PTFE is the best material for applications involving aggressive chemicals and for friction or temperature rating, but it suffers from poor mechanical properties and economic performance.

Parameter	PTFE	Nylon	PEEK	Acetal	HDPE
Chemical Resist.	Excellent	Good	Very Good	Good	Good
Friction	Very Low	Low	Moderate	Moderate	Moderate
Temp. Resistance	Up to 260°C	Up to 120°C	Up to 250°C	Up to 100°C	Up to 120°C
Strength	Low	High	Very High	High	Moderate
Cost	High	Moderate	Very High	Moderate	Low
Wear Resistance.	Moderate	High	High	High	Moderate
Moisture Abs.	None	High	Low	Low	Low

Specific Applications for PTFE Sheets

• Chemical Treatment Industry

PTFE plates are widely used in chemical processing due to their incredible chemical resistance. They are even used since they are competent enough to cover the tanks, vessels, and piping that come into contact with powerful acids, alkalis, or solvents.

• Food Industry

PTFE sheeting is in high demand in the food industry because of its safe characteristics and no need for prior application. These thin flat pieces serve as a surface for transmitting goods and materials where PTFE conveyor belts come into contact, gaskets, and no-adhesive surfaces for equipment utilized to process foods.

• Electrical and Electronic Industry

In this industry, PTFE sheets can be easily applied to mechanical, thermal, and soft terminations. In electronic appliances, PTFE sheets are widely used in insulating, cable sheathing, and printed circuit boards.

• Medical And Pharmaceutical Industry

Polytetrafluoroethylene has found very few medical applications due to its biocompatibility and resistance to chemical attacks. This includes infusing in medical tubing, lining surfaces of lab equipment, and gasketing within the scope of the manufacture of medicine.

• Space Industry

The high temperature withstanding ability, weight-to-strength ratio, and other factors make PTFE sheets indispensable in space technology. This material is utilized to create protective surfaces such as sealing, insulation, and coatings on the structures of spacecraft and aircraft.

PTFE and Its Use in Australia

PTFE (polytetrafluoroethylene) has shown itself to be helpful within many sectors of Australian industries due to its exceptional physical characteristics, chemical resistance, lower friction, and many other advantages. Within the mining and mineral resources sun sector in Australia, PTFE is used, for example, to line ducts, made available to every type of installation, deposits, and Rubber for neutralizing harmful technology materials, or for making shaped parts to withstand the effects of aggressive environments or such harmful chemicals as acids and alkalis. In addition, PTFE Gasket and Polymer Sheets also find use in farming, particularly in farms and cultivation systems such as irrigation and machinery, as they have excellent nitrogen protection in short-lasting.

Moreover, Australia’s buildings and construction sector has not been left out in the use of PTFE due to its durability and compatibility with dynamic systems. The industry has reported an increase in the country’s consumption of PTFE. The volume pattern of the market PTFE distribution in Australia according to contraction (lines) and expansion (growth) is increasing and is expected to grow by about 4% every year. It is what should make the order equilibrium. I confidently observe that the usage of PTFE will be significantly increased in green energy projects, while certain modifications enhance its application in solar energy and batteries due to its high heat resistance and prevention of electrical weak areas. These developments demonstrate that using Teflon is not only possible but is bound to grow in all areas of the zone’s traditional and new industries.

Reference Sources

1. Tribological Analysis of Engineering Plastics/Steel Friction Pairs

• Authors: R. Keresztes et al.
• Published In: Transactions of the Indian Institute of Metals
• Publication Date: April 17, 2021
• Summary:
  • This study investigates the tribological properties of various engineering plastics, including PTFE, when in contact with steel surfaces.
  • The research focuses on the coefficient of friction and wear rates under different loading conditions.
  • Key findings indicate that PTFE exhibits lower friction coefficients than other engineering plastics, making it suitable for applications requiring low friction and wear resistance.
  • The methodology involved experimental tribological testing using a pin-on-disk setup to measure friction and wear under controlled conditions(Keresztes et al., 2021, pp. 1537–1548).

2. Investigation of the Influence of Nylon-6 vs. Nylon-66 on the Mechanical Performance of Composite Bone Tissue Scaffolds

• Authors: Brandon Coburn et al.
• Published In: Volume 3: Advanced Manufacturing
• Publication Date: October 29, 2023
• Summary:
  • Although this study primarily focuses on Nylon-6 and Nylon-66, it provides insights into the comparative performance of these materials against PTFE in biomedical applications.
  • The research investigates the mechanical properties of scaffolds made from different materials, including PTFE, for bone tissue engineering.
  • Findings suggest that while Nylon-66 exhibits higher stiffness, PTFE’s unique properties make it suitable for specific applications requiring flexibility and biocompatibility.
  • The methodology involved mechanical testing of scaffolds fabricated through 3D printing(Xiang et al., 2023).

3. Friction and Wear Characteristics of Magneto-rheological Fluid Depend on Surface Coated by DLC and PTFE

• Authors: Peng Zhang et al.
• Published In: Journal of the Korean Society of Tribologists and Lubrication Engineers
• Publication Date: April 30, 2015
• Summary:
  • This study examines magneto-rheological fluids’ friction and wear characteristics in contact with surfaces coated with PTFE and diamond-like carbon (DLC).
  • The research highlights the advantages of PTFE coatings in reducing friction and wear in lubrication applications.
  • Key findings indicate that PTFE coatings significantly enhance the performance of magneto-rheological fluids, making them suitable for various industrial applications.
  • The methodology included tribological testing under controlled conditions to measure friction coefficients and wear rates(Zhang et al., 2015, pp. 62–68).

4. Top PTFE CNC Machining Parts Manufacturer And Supplier In China

Frequently Asked Questions (FAQs)

What are the applications of PTFE?

PTFE, often called Teflon, is widely used in various applications due to its exceptional chemical resistance and non-stick properties. It is a popular choice for industrial applications with strong acids and bases, making it suitable for chemical processing equipment. Additionally, PTFE is commonly used in electrical insulation due to its excellent dielectric properties, which make it ideal for electrical applications. Its applications also extend to medical devices, where biocompatibility is highly valued. Understanding the specific requirements of each application is crucial for selecting the right material.

How does PTFE compare with PEEK?

When comparing PTFE and PEEK, it’s essential to recognize that PEEK is a semi-crystalline thermoplastic known for its high mechanical strength and dimensional stability under extreme temperatures. While PTFE offers superior chemical resistance and non-stick properties, PEEK excels in applications requiring high mechanical performance and thermal stability. The choice between PTFE and PEEK often depends on the application’s specific requirements, such as exposure to harsh environments or the need for strength. This comprehensive comparison helps in choosing the right material for engineering applications.

What is the mechanical strength of PTFE compared to other engineering plastics?

PTFE has unique properties that contribute to its mechanical strength, but it is generally not as strong as some engineering plastics like PEEK or polycarbonate. While PTFE offers excellent dimensional stability and can withstand extreme temperatures, it may not be the best choice for high tensile strength applications. Understanding the differences in strength among various engineering plastics is crucial for selecting the right material for your project. A detailed comparison of PTFE with other materials can provide insights into the best options for applications requiring both chemical resistance and mechanical strength.

What role does PTFE play in medical devices?

PTFE is increasingly utilized in medical devices due to its biocompatibility and exceptional chemical resistance. Its non-stick properties make it an ideal candidate for applications where a low-friction surface is needed, such as in surgical instruments and implants. Additionally, PTFE can withstand sterilization processes without degrading, which is crucial for ensuring the safety and efficacy of medical applications. When selecting materials for medical devices, understanding the specific requirements and the chemical environment is essential for ensuring patient safety and device performance.

How do you choose the right material for engineering applications?

Choosing the right material for engineering applications involves understanding the project’s specific requirements, including mechanical, thermal, and chemical properties. Factors such as dimensional stability, electrical insulation, and the ability to withstand extreme temperatures must be considered. PTFE is often used for its exceptional chemical resistance, while other engineering plastics may be preferred for their mechanical strength. This process of selecting materials is crucial to ensure that the final product meets performance expectations and safety standards. Ultimately, the best material for your project depends on a comprehensive assessment of all these factors.