Arkema Inc. says Underwriters Laboratories (UL) has granted a final relative thermal index (RTI) rating of 150 degrees C mechanical and 140 degrees C dielectric for its Kynar film, which is used in the construction of photovoltaic backsheets.
The primary function of the Kynar film is to protect the backsheet so it does not degrade over the life of the module. Kynar film provides protection for the PET layer and resists degradation. This film is resistant to weathering and provides long-term UV protection for the underlying PET film, Arkema says.