Teflon ® – PTFE – Polytetrafluoroethylene
Teflon®, or Polytetrafluoroethylene, is also called polytetrafluoroethylene. It is a semi-crystalline thermoplastic. We can obtain it by polymerizing tetrafluoroethylene. The bonds that occur in this process are very durable. It is thanks to them that PTFE is characterized by exceptional chemical resistance – even at high temperatures. The degree of their crystallinity reaches up to 94%. Depending on the amount of fluoride, the density of this substance can even reach 2.2 g/cm3. At the same time, it makes it the material with the highest density. Polytetrafluoroethylene is distinguished by high thermal and chemical resistance. This makes it one of the most resistant plastics.
What does PTFE stand for?
PTFE abbreviation comes from the English language. It stands for polytetrafluoroethylene, i.e. polytetrafluoroethylene.
History of Teflon – when was Teflon invented?
The history of Teflon goes back to 1938. It was then that the chemist Dr. Roy J Plunkett of DuPont worked on gases related to Freon refrigerants. Upon examination of a compressed, frozen tetrafluoroethylene sample, it was found that this sample had spontaneously polymerized. She became a white, waxy solid. It was she who gave rise to PTFE.
The Teflon ™ trademark was created and registered less than 7 years later. Today, the PTFE family is gradually expanding with newer and newer materials. The discovery of PTFE became a kind of revolution in the industrial world. It brought many new solutions, finding its unlimited applications that effectively changed our world.
PTFE – Material
In terms of chemical resistance, polytetrafluoroethylene is far superior to all other plastics. It does not dissolve in any solvents known to us and is non-flammable. Moreover, it does not absorb water. However, it is not resistant to single metals such as fluorine, hydrogen fluoride, potassium and sodium. It decomposes only at a temperature of + 400 degrees Celsius. It also releases harmful gases. It is susceptible to loads and deformations. It does not conduct heat. In addition, it can boast a wide range of properties, such as:
- Physiological indifference – up to a temperature of + 270 degrees. Celsius is harmless to the body
- Neutral to hydrolysis and water vapor
- Resistance to UV rays
- Non-Toxicity; resistance to fungi and microorganisms
- Antistatic / Insulating depending on type
- High temperature of use
- Aging resistance
PTFE – Material features
Moreover, PTFE boasts a very wide application temperature range. In his case, it is from -200 degrees. Celsius up to + 260 degrees.
To further increase the strength and resistance of this material, fillers are also used, such as:
- Graphite / carbon
- Molybdenum disulfide
Thanks to its wide range of unique properties, polytetrafluoroethylene can boast an equally wide range of applications. It is used in many industries, mechanical engineering, transport, electrical engineering and laser technology. It is perfect for the production of pumps, exhaust gas treatment, cryotechnics, as well as for the production of laser and medical devices and in foodstuffs. It is used in sealing materials, implants, hydrophobic coatings and in all materials that work at high temperatures or come into contact with chemicals.
PTFE – Wide Application
Teflon has found its application mainly in the production of pans. Teflon coated pans prevent food from sticking to their bottom.
PTFE with an admixture of carbon allows for excellent antistatic properties. As a result, sliding profiles are produced which are used in places that are exposed to the formation of electric charges and where there is a high operating temperature.
PTFE with an admixture of bronze is a material of very high hardness and strength – also for abrasion, compression, and at the same time with a low coefficient of friction. Due to its low temperature expansion and good thermal conductivity, PTFE with bronze admixture is used in the production of plain bearings, bushings and tank linings in pipelines.
PTFE O-rings – Teflon O-rings
O-rings are seals made of many different materials. Most often, we can meet rubber orings made of rubber-like materials – e.g. SBR, NBR rubber, milk silicones and technical red ones. Plastic O-rings are most often made of polyamides, polyacetals, polyethylenes and Teflon PTFE.
PTFE o-rings are made of polytetrafluoroethylene. They are characterized by extremely high resistance to virtually all chemical stimuli (except for alkali metals such as sodium, potassium, fluoride and hydrogen fluoride). They are distinguished by high temperature resistance in the range of -200 degrees. Celsius to + 260 degrees. It is thanks to the unique features of PTFE that O-rings made of this material are so eagerly chosen by designers. Teflon o-rings can boast of:
- Low coefficient of friction
- Low plasticity
- High hardness
- High chemical resistance
- They are also great insulators