ETFE, or ethylene tetrafluoroethylene, is a clear plastic polymer used in a wide range of industries. Architects love this thin film as a coating on windows because it gives them better control over the environmental conditions inside of buildings. Coating Systems explains how the physical properties of ETFE make it so versatile.
Working Temperature Range
ETFE maintains its properties in temperatures ranging from -325 to 300 degrees Fahrenheit (−200 to 150 Celsius). This makes it a suitable film covering for all types of weather conditions on Earth, such as protecting glass windows at science stations in Antarctica or in buildings that receive a lot of sunlight in tropical climates.
ETFE’s propagating tear strength, or how it resists tearing, is around 3 Newtons (0.65 pounds) at 1 mil of thickness. Think of tear strength when taking out the trash. High-quality trash bags are harder to tear compared to lower-quality materials of the same thickness. In the same way, ETFE has greater tear resistance compared to similar films. If it does tear or crack, engineers can easily cover the film with another layer.
Friction Versus Weight
One benefit of ETFE is that not a lot of things stick to it, making it ideal for applications where friction is a concern. The coefficient of friction is 0.3 to 0.4, with a lower value meaning less friction (less friction is better in this case).
While FEP and PTFE have less friction, their specific gravities are 22 percent higher compared to ETFE (2.15 versus 1.76). ETFE’s specific gravity makes it lighter at similar thicknesses to comparable clear coatings. (Specific gravity measures how well something floats on water; everything above 1 sinks.) The lower specific gravity of ETFE makes up for its higher coefficient of friction compared to FEP and PTFE.
ETFE doesn’t add a lot of weight to objects with lots of windows. It also prevents other substances from sticking to the film. Rain drops, dust particles, pollen, and snow will slide right off of slanted roofs coated in this polymer. ETFE also works well as a thermoplastic liner in tanks for corrosion resistance because of low friction.
Solar transmission of ETFE ranges from 90 to 95 percent, meaning most of natural sunlight transmits through the film. This coating ideal for greenhouses and windows that let in natural light. Almost complete solar transmission is one reason why architects love this coating on buildings.
Inert to Outdoor Exposure
Perhaps ETFE’s most telling quality is how long it lasts when exposed to outside weather. Estimates range from 15 to 20 years based on laboratory testing when exposed to UV radiation, temperature changes, and weather. This coating works in outdoor applications that must resist extreme weather, such as wire, pipe, or tank coatings.
Talk to Coating Systems Regarding ETFE
Coating Systems can show you how ETFE benefits your company in a wide range of applications. Give us a call today at 1-800-593-7754 or contact us online for a consultation.