They are sometimes mistakenly confused and interchanged with each other, or even considered the same thing by laypeople, but they are actually two very similar materials but composed of two different types of polymers, each with its own specific characteristics.

What are the differences between ETFE and PTFE?

The main difference between ETFE and PTFE lies in the chemical composition.

ETFE stands for Ethylene-Tetrafluoro-Ethylene, a thermoplastic polymer containing fluorine atoms, which, due to their exceptionally strong bonding, result in a transparent plastic material capable of withstanding high levels of thermal stress and chemical aggression.

The ETFE film material is formed directly from the material and has good durability, ease of cleaning and stability. Being a film, it does not have a fabric core and is currently the most advanced in the world.

PTFE, which stands for Poly-Tetrafluoro-Ethylene, is a chemically inert material that uses glass fiber as the base material to form a membrane. PTFE is also characterized by excellent durability, mechanical strength, flexibility and ease of cleaning.

ETFE is resistant to a temperature range of -70℃ to 220℃, while PTFE has a slightly higher range of -80°C to 260°C.

The two material’s chemical and corrosion resistances are very similar, as is its resistance to weathering, while ETFE’s resistance to creep and compression are better than that of PTFE.

Both materials are characterized by their light weight and ability to absorb large amounts of infrared light, a quality that can be exploited to improve a building’s energy consumption. In addition, both ETFE and PTFE are found to be immune to ultraviolet rays, pollution and other environmental weathering, including sea spray, and thus are distinguished by their long service life.

The materials have been extensively studied and tested in laboratory and field environments, concluding that no loss of strength or discoloration of ETFE and PTFE covers has occurred over time.

Among the advantages of ETFE are its high transparency: it can transmit up to 95 percent of outdoor light and has been chosen for projects such as stadiums with grass surfaces, where full-spectrum natural light and light transmission are essential to support plant growth.

ETFE film has higher light transmission and better chemical resistance than PTFE film, along with strong resistance to natural aging.

In contrast, because ETFE film is formed directly from plastic without a substrate, its tensile strength and tear strength do not reach the levels of those of PTFE film.

ETFE stands for Ethylene-Tetrafluoro-Ethylene, a thermoplastic polymer containing fluorine atoms, which thanks to their exceptionally strong bond, give life to a transparent plastic material able to withstand high levels of thermal stress and chemical aggression.

EFTE is used in tensile panels or pneumatic cushions that cover architectural buildings, usually embedded in a lightweight aluminum structure.

The construction phase of the EFTE involves the assembly of several overlapping layers welded together: a system that recreates a real air chamber able to control the degree of permeability to light and heat of the individual elements, affecting the level of insulation of the envelope and its energy performance.

History of ETFE

ETFE was discovered by American chemist Roy Plunkett in the 1940s inside a cylinder of tetrafluoroethene occlusase following a mistake.

The first application that was thought at that time was in the military sector, until in the early ’80s, a mechanical engineering student from Bremen, Stefan Lehnert, a passionate sailor, researching new technologies for sailing, found in ETFE incredible potential suitable for the construction industry.

In 1982 the first building made of ETFE was built: the “Mangrove House,” a large pavilion intended for the Dutch Zoo in Arnhem, although the project that really made this material famous was the “Eden Project,” a massive geodesic greenhouse built in Cornwall in 1996, considered one of the best results of integration between sustainable architecture and environmental restoration.

Characteristics of ETFE

• The main feature that intrigued designers and led them to use ETFE in architecture is undoubtedly its lightness (350 g/sqm). The low weight makes structures made from this material preferable from a design point of view, and transport and assembly costs are much lower.
• Another important characteristic of ETFE is its thermal resistance. The extremely strong chemical composition leads to a resistance capacity around 170° without altering its physical properties: ETFE is fireproof and self-extinguishing thanks to the presence of fluorine.
• Another amazing feature of this material is its ability to resist the attack of UV rays. While other plastics that are usually used to replace glass tend to yellow after a while, ETFE does not yellow and with proper maintenance can last up to 40 years. What’s more, when its cycle of use is over, the membrane is melted down and reused, thus obtaining a 100% recycling rate.
• ETFE is also an excellent thermal insulator, which is why, when used, there is a significant reduction in energy costs for the maintenance of structures.

Canobbio Textile has carried out numerous architectural projects in ETFE, including the skylight of the San Raffaele Hospital in Milan and the Korce Sport Center in Albania, to mention some of the most prestigious examples.