B+K is presenting this pioneering film solution at the SNEC PV POWER EXPO, 28. - 30. May 2018, in Shanghai and at the Intersolar, 20. - 22. June 2018, in Munich.
This new generation of backsheets is significantly more resistant to weathering and increases the modules' safety. PET-based backsheets have been the norm so far. These tend to become brittle, particularly in humid climates. The solution developed by B+K uses a polyolefin, and reveals a lifespan that is significantly longer than that of the market standard in accelerated weathering tests. The use of polyolefin as a material additionally increases the modules' electrical safety. For example, the electrical breakdown voltage, and thus the insulation capacity, of B+K's backsheet are more than twice as high as those of comparable products on the market.
Photovoltaic modules usually have a multi-layer sandwich structure. The final film on the rear side protects the interior of the module from environmental influences such as UV radiation or moisture. At the same time, this backsheet protects the solar cells from mechanical damage and ensures electrical safety throughout the product life, which is normally over 20 years.
The backsheets usually found on the market consist of individual films that are permanently bonded with solvent-based adhesive in a separate operation. If the adhesive breaks down over time, there is a risk of the layers separating. B+K BackFlex® PP backsheets are produced in one individual operation by means of co-extrusion. The bonding process step is forgone, and therefore also the use of solvents and adhesives. Layer separation is not possible.
The Bischof + Klein backsheets therefore also reduce energy consumption and costs, and make an important contribution to the sustainable production of photovoltaic modules and renewable energy generation.