ETFE, or ethylene tetrafluoroethylene, is a fluorine-based plastic with several unique properties that make it an attractive material for various applications, including building envelopes.
In terms of its use in construction, ETFE foil is often used as a cladding material for buildings and other structures. It can create unique and visually striking facades while also protecting the elements.
ETFE has been used in several high-profile projects, including the Allianz Arena in Munich and the Water Cube in Beijing.
In the following article, you can learn about the ETFE history and the top 10 benefits of the ETFE systems.
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Over 40 years ago, DuPont developed ETFE (Ethylene Tetrafluoroethylene) as an inert coating substance for the aerospace industry. ETFE foil has now proven its value in the architectural industry in addition to its former traditional uses in agricultural applications like greenhouses or for coating solar cells.
The Eden Project in Cornwall, United Kingdom, has already demonstrated ETFE’s enormous potential.
With three significant undertakings, the 1998 Eden Zoo project, the 2006 Soccer World Cup’s Allianz Arena, and the 2008 Beijing Olympics’ “Water Cube,” ETFE film has gained recognition. It is now considered the premium material for transparent cladding applications in roofing or facade construction.
1. High light transmission rate
One of the primary reasons ETFE is used in building envelopes is its ability to transmit light while protecting it from the elements. ETFE is a transparent material highly resistant to UV radiation, making it ideal for use in applications where sunlight is a factor.
ETFE films can be highly transparent (from 90% to 95%) and allow for the passing of UVs, which promote photosynthesis, thus facilitating plant growth. This makes it an excellent choice in skylights, atriums, and other areas where natural light is desired.
2. It is lightweight
Another reason that ETFE is used in various applications is its low weight. It is significantly lighter than other materials, such as glass or steel, which makes it easier to handle and install.
This factor is significant in applications where weight is a factor, such as in the construction of high-rise buildings or other structures where the engineers must carefully consider weight.
3. It is durable and resistant to weathering.
Under exposure to environmental pollution, UV light, harsh chemicals, or extreme temperature variations, ETFE does not degrade.
ETFE is resistant to UV radiation, making it resistant to fading and discoloration. ETFE is also resistant to extreme hot and cold temperatures, making it suitable for various climates.
In addition to its weather resistance, ETFE is also highly durable. It is resistant to punctures and tears, making it ideal for use in areas where it may be subject to wear and tear. ETFE is also resistant to chemical corrosion, making it suitable for use in environments where it may be exposed to harsh chemicals.
4. Energy efficient
From extruding the film to transportation to the site, compared to similar cladding materials, little energy will be consumed, thus reducing the overall carbon footprint.
In addition, the product’s nature enhances the building physics through insulation and daylighting, contributing to the global low energy aspect.
5. Solar Control/Shading
ETFE film systems can incorporate several frit patterns on one or multiple layers to alter their solar performance. The foil is printed with various standard or custom patterns.
Colors can be introduced in various ways, whether applied during the film extrusion process providing a consistent tint on multiple tones from red to violet, or adding lighting with unlimited color options.
While ETFE films are very elastic (up to 600% at breaking point), they are still structurally resistant. The tensile strength at the limit of elasticity/plasticity is 21-23 N/mm², but the tensile strength to the breaking point is 52/Nmm². For structural calculation, a limit of 15 N/mm² is usually conservatively taken.
ETFE can be easily fabricated into various shapes and sizes, making it a versatile material for many applications.
Due to the lightweight nature of ETFE, substructure support systems and concrete foundations can be designed more efficiently. ETFE systems also provide ample natural daylighting, thus minimizing energy costs by lowering the demand for indoor lighting.
It is the appropriate building component where abrupt extreme loads, such as earthquakes or blasts, may occur because of the remarkable resilience and elasticity of ETFE.
In contrast to glass, which may shatter and raise severe concerns in scenarios with similar shock loads, ETFE will either deflect under load or, even in the event of breaking, is unlikely to result in any significant damages. However, ETFE is ineffective as a vertical guardrail and cannot deter infiltration.
9. It is recyclable
Easily recyclable, waste from the manufacturing process or even old ETFE elements can be remolded into new ETFE products such as tubing components, wires, or castings. This makes ETFE an environmentally-friendly choice for building and construction projects.
10. Low maintenance
Due to the non-adhesive surface properties of the ETFE, deposits of dirt, dust, and debris do not stick and are washed away by the rain resulting in a “self-cleaning” effect. However, as for all mechanical equipment and its components, it is necessary to perform a yearly inspection.
The inspection includes checks on the air inflation units and filter replacements. The ETFE film and its attachments will also be inspected for possible damages to prevent further issues.
In conclusion, ETFE is a highly versatile and durable material well-suited for building envelopes and other applications where natural light is desired. Its high light transmission rate, resistance to UV radiation, and durability make it an excellent choice for various projects.