ETFE

ETFE
Identifiers
CAS number 25038-71-5 Y
ChemSpider 140652 Y
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Ethylene tetrafluoroethylene, ETFE, a fluorine based plastic, was designed to have high corrosion resistance and strength over a wide temperature range. ETFE is a polymer, and its systematic name is poly(ethylene-co-tetrafluoroethylene). ETFE has a very high melting temperature, excellent chemical, electrical and high energy radiation resistance properties. When burned ETFE releases hydrofluoric acid.

Contents

Chemical, mechanical, physical, and thermal properties

Useful comparison tables of PTFE against FEP, PFA and ETFE can be found on DuPont's website, listing the mechanical, thermal, chemical, electrical and vapour properties of each, side by side. [1]

ETFE is effectively the high strength version of the other three in this group, often featuring slightly diminished capacities in other fields by comparison.

Combustion of ETFE occurs in the same way as a number of other fluoropolymers, in terms of releasing hydrofluoric acid (HF). HF is extremely corrosive, and so appropriate caution must be exercised.

Compared to glass, ETFE film is 1% the weight, transmits more light and costs 24% to 70% less to install. It's also resilient (able to bear 400 times its own weight, self-cleaning (due to its nonstick surface) and recyclable. On the other hand it is prone to punctures by sharp edges, therefore it is mostly used for roofs.[2] In sheet form as commonly employed for architecture, it is able to stretch to three times its length without loss of elasticity. Employing heat welding, tears can be repaired with a patch or multiple sheets assembled into larger panels.

ETFE has an approximate tensile strength of 42 N/mm² (6100 psi), with a working temperature range of 89 K to 423 K (-185 °C to 150 °C or -300 °F to 300 °F).[3]

Applications

An example of its use is as pneumatic panels to cover the outside of the football stadium Allianz Arena or the Beijing National Aquatics Centre (a.k.a. the Water Cube of the 2008 Olympics) - the world's largest structure made of ETFE film (laminate). The panels of the Eden Project are also made of ETFE and the Tropical Islands have a 20,000 m² window made of this translucent material.

Another key use of ETFE is for the covering of electrical wiring used in high stress, low fume toxicity and high reliability situations. Aircraft and spacecraft wiring are primary examples. Some little wire like the wire used for the wire-wrap technique are coated with ETFE.

As a dual laminate, ETFE can be bonded with FRP as a thermoplastic liner, and used in pipes, tanks, and vessels for additional corrosion protection.

ETFE is commonly used in the nuclear industry for tie or cable wraps, and in the aviation and aerospace industries for wire coatings. This is because ETFE has better mechanical toughness than PTFE. In addition, ETFE exhibits a high-energy radiation resistance and can withstand moderately high temperatures for a long period of time. Commercially deployed brand names of ETFE include Tefzel by DuPont, Fluon by Asahi Glass Company , Neoflon ETFE by Daikin,and Texlon by Vector Foiltec.

Due to its high temperature resistance ETFE is also used in film mode as a mold release film. ETFE film such as PMP Film by Honeywell is used in aerospace applications such as carbon fiber pre-preg curing as a release film for molds or hot high pressure plates.

Buildings using ETFE

Newly built: Oceanus Casino, Macau, Special Administrative Region of China.

References

  1. ^ Fluoropolymer Comparison - Typical Properties DuPont
  2. ^ ETFE
  3. ^ Tefzel ETFE Specifications

External links