Mylar® UVHPET™ for PV Backsheets

When it comes to Polyester based backsheets, not all films are created equally

Too often in the PV industry generic PET films are referred to when talking about field failures which simply do not have the material properties needed to withstand the stresses seen in demanding back sheet applications. All Mylar® UVHPET™ products offer enhanced UV barrier and hydrolysis resistance, and are extensively tested to ensure durability and reliability with a series of test protocols aimed at replicating the impact of weathering for more than 25 years in a variety of different climatic conditions.

Mylar® UVHPET™ - the sustainable back sheet material without compromise in durability or performance

With zero reported field failures, our product testing protocols exceeds industry standards and is backed up by the ongoing monitoring of our products in real life applications across the globe. As well as DuPont Teijin Films own internal tests, we also routinely test against ISO and IEC standards and the range of Mylar® UVHPET™ also pass DuPont’s MAST testing with minimal colour change and excellent retention of physical properties. Mylar  UVHPET™ also deliver enhanced levels of protection from surface damage compared to some alternative back sheet materials, protecting the module from abrasion in harsh climates such as deserts and from damage which can be caused during installation and cleaning.

Design for recycling and boosting circularity in the PV industry

Sustainability and the drive for circularity in the solar industry guides the development of our product range.  Mylar® UVHPET™ offers significant advantages over both fluorinated back sheet and double glass modules in terms of the overall carbon footprint of the product.

However, it is at the end of the module’s life where the choice of back sheet material is most critical with fluorinated back sheet material presenting significant environmental and health issues in disposal processes such as incineration and pyrolysis. Mylar® UVHPET™ is halogen free and does not generate hazardous materials in high temperature disposal processes.

Enabling the growth in bifacial modules

Building on the success of our white Mylar® SPV range and black Mylar® 250, the latest addition to the Mylar® UVHPET™ portfolio of products is a range of ultra clear films designed to be used as outer, inner or mono layers in transparent back sheets. Transparent backsheets have a lower carbon footprint, are easier to clean and also can deliver a further efficiency gain of around 1% when compared to double glass modules. Bifacial modules are increasingly being adopted in areas with high ground albedos such as deserts, and the scratch and abrasion resistance of Mylar® UVHPET™ compared to other backsheet material gives an added level of protection in these harsh environments.

Mylar®  - The laminators choice for core layers in backsheet structures

Mylar® has been used for over 35 years as a core layer in backsheet laminate structures.  Mylar® inner films have enhanced hydrolysis resistance compared to standard PET films, passing over 2000 hours in damp heat testing.  Mylar® inner films  are specifically designed to perform in demanding lamination processes with low and balanced shrinkage and excellent lay flat properties.