PTFE may sound mysterious, but in reality, it’s one of the most versatile and widely used materials in the manufacturing industry. As a major advancement in modern science & technology, this innovative substance is now widely used by every person and in every industry - globally.

And that’s exactly what makes PTFE so amazing! It’s a material found in almost everything you use - from non-stick frying pans to the seat belt clips in your cars, there’s a big chance that you’ve actually used something that contains PTFE today without even knowing it.

What is PTFE Made From?

What is PTFE made from? PTFE is Commonly known by the registered trademark Teflon®, PTFE stands for polytetrafluoroethylene. Other trademarked brand names include Fluon, Hostaflon, and Polyflon.

PTFE is a fluoropolymer based on carbon and fluorine - hence the “fluoro” element in the name. It is also a polymer, meaning its molecular structure consists of a repeating pattern of large and similar particles. In this case, the particles are the compound tetrafluoroethylene, with a chemical formula of C2F4.

It was first discovered in 1938 by American company DuPont. Today, Teflon’s patent belongs to The Chemours Company, a chemist company spin-off of DuPont. However, many other manufacturing and industrial companies have since been producing their own PTFE-based products.

PTFE is well known for its versatile set of characteristics, making it highly suitable for an enormous range of applications. With its lack of reactivity to most other chemicals, a considerably high melting point, stability in very low temperatures, resistance to corrosion, insulating properties, durability, and slick, non-stick surface, PTFE has a virtually unlimited range of uses.

Most commonly, however, PTFE is used as a coating for other materials. Common examples include the coating of machine parts, construction materials, medical equipment such as catheters, cooking utensils, wiring, laboratory equipment and fabrics.

Is PTFE a Metal?

PTFE is not a metal. One of the defining properties of metal is its electrical conductivity, whereas PTFE is insulative. Nor is it rubber, even though it may kind of seem like one. So, while it isn’t technically a plastic, PTFE is effectively considered one because of its properties.

Rubbers, like plastics, are also polymers but possess the defining property of elasticity. Rubbers can be deformed, but hey will bounce back to their original form unless they are completely broken. On the other hand, plastics are defined by their plasticity, which means their shape and form can easily be manipulated by heat or force. PTFE belongs in the latter category.

How is PTFE Made?

The production of PTFE can be summed up in two main stages:

the synthesising of TFE or tetrafluoroethylene, and the polymerisation of the TFE to make it PTFE.

Remember, PTFE stands for polytetrafluoroethylene.

Here’s a basic, abbreviated version of the production process:

This process starts with four key components: fluorspar, hydrofluoric acid, chloroform, and water. These ingredients, minus water, are synthesised into TFE using a process called pyrolysis.

The three components are placed in a chemical reaction chamber and heated to temperatures high enough to alter their chemical composition.

Once the TFE is created, it is cooled to prevent a reverse reaction and potentially explosive decomposition.

It is then turned into liquid and mixed with clean water in the reaction chamber. Iron is used as a reaction catalyst. The polymerisation of TFE into PTFE will then begin, and solid grains of PTFE will be formed.

However, it is important to note that this is just a very basic rundown of the process of making PTFE. There are often other steps involved to control the form and properties of the final product, depending on the manufacturer. In fact, different manufacturers may have different production processes.

What Are the Types of PTFE?

PTFE can be filled with other materials to slightly alter its properties based on the needs of the application or product to be manufactured. Below we look at the three most common fillers of PTFE:

Carbon-filled PTFE

Filling PTFE with carbon generally makes it more robust than PTFE alone. Carbon-filled PTFE offers higher compressive strength, as well as general deformation, creep, and wear resistance. Because carbon itself is also conductive, filling PTFE with carbon also erases its insulative properties and makes it a better conductor for both heat and electricity.

Glass-filled PTFE

Glass-filled - particularly fibreglass - is the most common kind of filled PTFE.  The effects are quite similar to carbon filling, as glass also increases PTFE’s durability. Filling PTFE with glass similarly increases compressive strength and resistance to surface pressure and decreases flexibility. Glass also makes the PTFE more chemically resistant. It also maintains or even improves upon PTFE’s insulating properties.

However, the downside is that glass-filled PTFE generally has a significantly more abrasive surface, effectively removing pure PTFE’s smooth, slick surface. Glass filling also doesn’t increase the conductivity of PTFE the way carbon does.

Copper-filled PTFE

Copper or bronze-filled PTFE is also more durable than virgin PTFE, although not to the extent of carbon- or glass-filled PTFE. But what copper or bronze filling mainly does is to drastically increase the material’s conductivity - to the extent that it’s more of a conductor than an insulator. In fact, bronze-filled PTFE can be up to 10 times more conductive than unfilled PTFE. It also has more friction resistance than that of other fillings.

Copper-filled PTFE is, however, more chemically reactive and is thus more vulnerable to corrosion than your regular PTFE or glass- or carbon-filled PTFE. This is mainly due to bronze being easily oxidised.

It’s important to note that manufacturers often offer varying amounts of filling in their PTFE products to meet the client’s needs. It’s also not uncommon for manufacturers to fill PTFE with different mixed ratios of these fillers, aiming to balance their effects and achieve the ideal mix of properties.

What Are The Properties of PTFE?

PTFE can be used in numerous applications thanks to its many desirable properties as a manufacturing material. In fact, it’s so widely used that PTFE is a staple part of common construction projects – including bridges, car parks, supermarkets, schools, etc.

Let’s first take a look at its properties and limitations below.

Properties & Advantages of PTFE 

Non-wetting characteristics

Does not embrittle or age

Medical, industrial and food-grade material

Low water absorption

Low coefficient of friction and low dielectric constant/dissipation factor

Good fatigue resistance when under low stress

Resistant to strong, corrosive chemicals

Resistant to high heat and low temperatures

Resistant to light and UV

Resistant to weathering

Highly flexible

Smooth surface finish achievable after fabrication

Limitations of PTFE 

Compared with other polymer materials, it is not low-priced

Not easy to mass-produce

Cannot be cemented or welded

Can be difficult to join

If under enough pressure, it can change its shape

While it can withstand very high temperatures, it melts at 326˚C

Low resistance to radiation

Abrasion and creep sensitive

Is PTFE safe?

There have been concerns raised in the past about the safety of PTFE, mainly when used in cooking materials such as non-stick pans. The issue centred around the chemical PFOA or perfluorooctanoic acid, which was used in the making of Teflon-coated cooking equipment.

However, it is important to note that most (if not all) of the PFOA used in making PTFE-coated products is gone after the manufacturing process is complete. But, more importantly, Teflon-coated cooking equipment has been PFOA-free since 2013, when health associations raised concerns. As long as PTFE-coated frying pans aren’t heated over 300 degrees Celsius, they won’t break down enough to cause health hazards or safety issues.

What is the compressive strength of bronze-filled PTFE?

Compressive strength (or compression strength) refers to a material's capacity to withstand loads that tend to reduce in size. It is the opposite of tensile strength. Adding Bronze to PTFE provides better dimensional stability and a higher compressive strength of 10.5 MPa at 1% deformation.

Who invented PTFE?

PTFE was accidentally discovered in 1938 by Roy J. Plunkett while working for DuPont. He was trying to invent a better based cooling gas than what was available at the time. He was using chlorofluorocarbon and left it overnight. When he returned, what he discovered instead was PTFE.