PTFE: THE PROPERTIES THAT MAKE IT IDEAL FOR INDUSTRIAL APPLICATIONS

Polytetrafluoroethylene (PTFE), commonly known as Teflon, is a fluorinated polymer of incredible performance. These characteristics make it particularly expensive. It is used when application requirements cannot be met by other engineering polymers. A practical example are chemically aggressive environments or those with excessive temperatures.

The main distinguishing feature of Teflon is that most of its chemical bonds are between Carbon and Fluorine (CF bond). This aspect makes its molecules particularly stable. It means that they are able to withstand very high thermal stresses, as well as high-level chemical aggression.

These factors make Teflon much stronger than similar polymers. This is why we rely on this material when no other polymer can meet very stringent application requirements ranging from high to extreme.

HOW POLYTETRAFLUOROETHYLENE (PTFE) WAS BORN

The first of the known fluorinated polymers is polytetrafluoroethylene (PTFE). It was discovered back in 1938 by chance during experiments involving fluorinated refrigerants.

Initially, the material was designed and developed to meet certain requirements in the military defence field and for advanced technological applications. Subsequently, its use was gradually extended to the civil sector. Today, it is used for various applications and is considered one of the most indispensable materials.

From the very beginning, the characteristics of this innovative polymer made it clear that it was a material with unique properties. In fact, Teflon does not suffer the aggression of any chemically derived reagents.

This is possible thanks to its slippery surface that does not allow any other material to adhere. In fact, Teflon is completely hydrophobic. In addition, it does not degrade when exposed to light and its melting point is extremely high.

All these properties led to the realisation that we were dealing with an innovative material with innumerable potential applications. Over time, it was also realised that it could be transformed into a variety of desired forms through the application of technologies similar to those used in the processing of metallurgical powders.

Thus, Teflon was born, a material marketed since the 1940s that still stands today as one of the most popular polymers in the industry.

HOW THE BASIC PRODUCTION PROCESS OF PTFE POLYMER TAKES PLACE

The production of the polymer PTFE takes place in two main steps. The first is the production of the TFE monomer through a synthesis process of calcium fluoride, sulphuric acid and chloroform.

Subsequently, its polymerisation is carried out by processes under extremely monitored conditions, leading to the formation of PTFE. The presence of CF (Carbon and Fluorine) bonds gives the molecules of this polymer an extraordinary chemical inertness, as well as excellent electrical insulation and friction characteristics.

THE MAIN PROPERTIES OF TEFLON, A CUTTING-EDGE, HIGH-PERFORMANCE MATERIAL

Teflon is a member of the fluoropolymer family whose main characteristics and properties are as follows:

• reduced adhesion. It is a material with low surface energy, a characteristic that enhances performance against adhesion of other substances;

• environmental resistance. Being transparent to sunlight and resistant to oxidation, it manages to keep its properties intact even in cold temperatures. It also resists aggression by microorganisms;

• absent contaminants. This type of fluoropolymer is pure and does not generate chemical pollution;

• high corrosion resistance. It can withstand the aggression of chemicals even in a high temperature range;

• heat resistance. In general, fluorinated polymers are capable of service temperatures of around 260°C, with higher peaks for shorter times.

In particular, as Teflon has no hygroscopicity, it is a material suitable for contact with food.

The specific thermal properties of Teflon

PTFE is characterised by a low coefficient of thermal transmission. For this very reason, it is considered a thermal insulator, is non-flammable, and is characterised by its stability even over long periods of time.

The chemical properties of PTFE

PTFE resists attack by almost every known chemical reagent. Only chlorine trifluoride, alkali metals and fluorine in its elemental state are able to attack it at high temperatures and pressures. Furthermore, Teflon is insoluble in any solvent up to 300°C.

It can only be melted or swelled when temperatures very close to the crystalline melting point are reached.

The mechanical properties of Teflon

The mechanical properties of Teflon are as follows:

• anti-adhesive;
• low coefficient of friction.

As far as theelongation at break is concerned, this is over 100 per cent. In addition, the shrinkage resulting from the machining process is high.

The dielectric properties of Teflon

PTFE is also characterised by its high dielectric properties over a high frequency and temperature range.

As there is no absorption of water, its characteristics remain unchanged even when exposed to the elements for a long time. In addition, the dielectric strength is not affected by the operating temperature.

FILLED PTFE: WHAT IT CONSISTS OF

To improve the properties of Teflon even further, special additives can be added. These are the so-called fillers that give rise to ‘filled PTFE’. Through this process, the properties we listed above are modified.

Well-known examples include: coal, graphite, bronze, fibreglass, ceramic powder. These substances can also be added by creating mixes between two or more fillers.

The following results can be achieved with additive powders:

• growth in compressive strength;
• greater resistance to wear and tear;
• higher chemical resistance;
• reduction in the coefficient of friction;
• greater thermal conductivity and resistance to deformation;
• change in surface and volume resistance;
• high non-stick;
• greater hardness.

All these additions enhance the already outstanding characteristics of Teflon, especially when used in particularly stressful applications.

TAFER, THE IMPORTANCE OF RELYING ON A PROFESSIONAL COMPANY

TAFER is a company that has been in the industry for more than 30 years and is distinguished by its dynamism and flexibility. Thanks to a professional and highly specialised team and the use of innovative, state-of-the-art equipment, it specialises in PTFE processing, the production of semi-finished PTFE products (virgin and filled) and PEEK processing.

Here too, TAFER produces both natural and filled PEEK semi-finished products. To its customers, the company also offers the following products and services:

• production of gaskets according to drawing;
• metal stamping;
• production of valve components.

In addition to PTFE and PEEK, TAFER also specialises in the production of semi-finished products made of PCTFE and DEVLON V-API both in Italy and throughout Europe.

The company also excels in the creation of customised parts and components from machining and in the production of technopolymers from injection moulding. For any technical or commercial information call us or contact us on the site.