Optically clear UV stable polyester films

“There is a perception that polyester films quickly degrade due to sunlight UV exposure, thus limiting the end use applications for clear polyester films,” said Scott Gordon, business development manager, DuPont Teijin Films.  “Also, there are double-sided substrate photo patterning applications where the UV transmission for side A patterning must be blocked from simultaneously patterning side B. These new MELINEX TCHUV films will provide our customers with cost-effective substrate solutions that are ideal for a wide variety of UV light sensitive applications.”  

Bi-axially oriented, semi-crystalline polyethylene terephthalate (PET) films have many desirable properties for a wide range of applications, including dimensional stability, chemical resistance, tensile strength and electrical insulation. Standard PET polyester films transmit light above approximately 315nm wavelength, however, extended UV exposure can lead to changes in optical and mechanical properties such as color and film brittleness. Utilizing proprietary UV stabilizer technology from DuPont Teijin Films, the clear MELINEX TCHUV films move the transmittance cut-off to about 375nm while enabling the PET film to retain mechanical and optical properties after accelerated UV aging.  The new films range in thickness from 50µm – 125µm, they maintain ~1 percent haze by minimizing the typical oligomer blooming effect that can be caused by exposure to elevated temperatures, and they are available with near-zero thermal shrinkage when processed through DTF’s world-class heat stabilization process.