PTFE (polytetrafluoroethylene)

Discovery of PTFE

The material was accidentally discovered by Dr. Roy J. Plunkett on 6 April 1938. He experimented with gases to find an adequate refrigerant for refrigerators. So, he stored a large amount of the gas tetrafluoroethylene in small steel bottles under a certain pressure at dry ice temperatures of approx. -80°C. He and his employees discovered colourless to whitish crumbs when taking samples. The tetrafluoroethylene had polymerised in the bottle under the given conditions to a white, waxy solid polytetrafluoroethylene. This was followed by further tests, which showed that not even aqua regia (65% nitric acid and 37% hydrochloric acid in a ratio of 1:3) could harm this material.

Areas such as industrial applications, medical technology, communication, aerospace, architecture and electronics owe their ground-breaking advances and innovations to the material polytetrafluoroethene. Even pans are coated with it.

Properties

PTFE has a very low coefficient of friction and therefore a high non-stick effect, so that products coated with it have a high level of sliding properties. Since the sliding friction is just as great as the static friction, there is no jolt when transitioning from standstill to movement, but a seamless merge into movement. The semi-crystalline plastic is actually opaque white, but thin layers of it appear translucent.

In addition, the material PTFE is water-repellent and almost non-flammable. It has a crystallisation melting point of approx. 342°C. Sintered finished parts made of polytetrafluoroethene, on the other hand, melt at a temperature of 327°C.

PTFE material is insensitive to numerous chemicals and IR, UV and HF radiation. Polytetrafluoroethene is frost-resistant down to -260°C and can be used for a long time at an operating temperature of up to 260°C; short term up to 300°C. Above 400°C, it decomposes with the formation of harmful vapours.

Processing

Polytetrafluoroethene is processed into various materials such as paste, suspension, modified suspension and emulsion polytetrafluoroethene, as well as PTFE compounds. Tapes, foils and sealing cords, for example, are made from emulsion PTFE.

In compounds, for example, glass fibres are used to achieve higher pressure and wear resistance. If bronze is processed with PTFE, the thermal conductivity increases. In addition to the thermal conductivity, graphite also increases the degree of hardness.

Advantages

Due to its many advantages, PTFE is particularly valued in industry and trade. In particular, the following advantages of PTFE stand out:

• Large temperature range
• High melting point
• Chemical resistance
• Chemical insolubility
• High flame resistance
• Physiologically harmless
• Water-repellent
• Extremely low coefficient of friction
• No aging or brittleness due to high UV and weather resistance
• Very pure material
• Free from additives
• Good electrical insulation

Areas of use and application

Polytetrafluoroethylene is used, for example, in saucepans, pans and other everyday objects, as well as in industrial plants for non-stick coatings. For a non-stick coating, PTFE is applied after chemical or mechanical pre-treatment and then sintered. During sintering, the crystallites of the material grow together at a correspondingly high temperature, so that the material layer solidifies.

In addition, PTFE is used for the coating of components or tools as well as for foils, sliding guides, hoses and sliding bearings.

Polytetrafluoroethene is used in the glass and solar industries, architecture, pump and valve construction, mechanical engineering, the automobile, plastics and textile industries.

Our available formats for PTFE

At Steinbach AG, you can get various PTFE conveyor belts and foils as well as various PTFE glass fabrics in many designs, for example as rolls or made up according to your wishes.

Use our large selection of polytetrafluoroethene materials for your success and benefit from our qualified advice.