Coveme offers monolayer, dual-layer, and aluminum-laminated backsheets, with moisture permeability ranging from 2.5 to 0.005 g/m²/d
The company promotes its Clr HDPYE and ECO rPET series for bifacial and sustainable module configurations, while APYE models target ultra-low WVTR
Coveme’s polymer frontsheets feature hard coatings for enhanced UV and abrasion resistance in 1,000 V and 1,500 V systems
Coveme, the Italian company, has been a pioneer of non-fluoropolymer-based backsheets, which remain its main focus. Most of its product range is based on a PET/PET/Primer construction. While PET has established itself very well as the ultimate material for the core layer of backsheets, its UV stability has always been questioned. Although unstabilized polyester films are indeed prone to UV degradation, Coveme believes that developments in polyester chemistry and advancements in manufacturing processes have enabled the development of UV-durable polyester.
The company has provided data for 26 products, which is the largest portfolio of non-fluoropolymer-based backsheets as well as the entire survey. It has added 3 new models to the 24 previously listed while discarding one. 18 out of the 26 listed products use primer – a polyethylene-based compound the company claims to have high bonding to EVA – as the inner layer, while the remaining 8 use inner coating. Coveme has not revealed the details for all of the mechanical properties and a few physical properties, which explains the blanks in the specification tables. All of Coveme’s PV-targeted polymer solutions are part of the dyMat series, which is also their common prefix. However, we’ve omitted it to help readers easily differentiate between the listed models.
The 3 new products from the company are HDPYE SPV LDO, HDPYE C M and Clr HDPYE LDO. HDPYE SPV LDO is a high-barrier backsheet designed for TOPCon and HJT cells and is made of PET / PET / Primer with an effective thickness of 420 μm ± 5%. This backsheet has a breakdown voltage of over 24 kV and a partial discharge rating of over 1,500 V DC. It has a low water vapor permeability of < 0.5 g/m²/d and reflectivity of > 75% on the EVA Side.
HDPYE C M is a monolayer backsheet offered with coating and a high-quality PET layer. It features a breakdown voltage exceeding 21 kV and a partial discharge rating of over 1,500 V DC. This backsheet is offered with an effective thickness of 305 μm ± 5% and a water vapor permeability of <2.5 g/m²/d.
Clr HDPYE LDO is the company’s third product to be featured for the first time in this section of the survey. The prefix ‘Clr HDPYE’ represents the company’s transparent backsheet product line promoted for bifacial and BIPV applications. Clr HDPYE LDO, the newest of the range, is a high barrier backsheet, built with 2 layers – PET and a primer – with an effective thickness of 420 μm ±5%. It features a breakdown voltage exceeding 21 kV and a partial discharge rating of over 1,500 V DC. The low water vapor permeability of < 0.8 g/m²/d and high-quality PET with UV stabilization make it suitable for applications needing transparency and high barrier properties.
Clr HDPYE LDO is recommended for bifacial configurations of TOPCon and HJT modules. Launched in 2022, Clr HDPYE SX LDO is yet another high-barrier transparent backsheet, but it is built with 3 layers of PET and a primer, resulting in a higher thickness of 433 μm. However, it has a low water vapor permeability of 0.1 g/m²/d and a lower breakdown voltage of 20 kV.
Clr PYE MONO F and Clr HDPYE F are coatings-based backsheets, also introduced in 2022. As their names indicate, Clr PYE MONO is monolayer-based with a coating applied on the PET with a thickness of 163 µm; and Clr HDPYE F has an additional layer of PET, resulting in an effective thickness of 320 μm, thus qualifying for the 1,500 V partial discharge criterion. The other product from this transparent backsheet range includes Clr PYE MONO, based on PET and primer construction with a thickness of 268 µm, and Clr HDPYE with 2 PET films and primer, accounting for a thickness of 370 μm.
Introduced in 2022, Coveme’s ECO series, with its 2 products, is somewhat special, given it is made of 33% recycled PET (rPET). The ECO r33 PYE MONO L PLUS is a dual-film configuration – a PET layer and a primer – with an effective thickness of 218 μm. Thus, the product only meets the 1,000 V system voltage. This backsheet has a high reflectivity of 90%, a water vapor permeability of < 2.2 g/m²/d and a breakdown voltage of > 17 kV. ECO r33 HDPYE SPV L is another rPET backsheet and is built with 2 layers of PET with a primer on the cell side. The effective thickness of this backsheet is 370 μm, meeting the requirements for 1,500 V. The product has a reflectivity of 83% and water vapor permeability of 1.8 g/m²/d. Both rPET-based backsheets have a width ranging between 50 and 1,500 mm.
PYE MONO C is a monolayer product launched in 2022, featuring a high-quality monolayer PET with an inner coating. The PYE MONO C standard backsheet comes in 2 color options – black and white – on the outside, but only white on the inside. This backsheet measures 162 μm in thickness and has a reflectivity of 90%. PYE MONO C BKHR, a 168 μm thick black backsheet, still features a high reflectivity technology with > 55% reflectivity.
Coveme is promoting its APYE series for PV technologies that demand a high-level moisture barrier, such as heterojunction (HJT), TOPCon and thin-film modules that are highly sensitive to water vapor. The backsheet is integrated with a sheet of aluminum between the core and outer layers of PET to provide a high level of protection from moisture ingress. The company says that it can also supply these backsheets with different thicknesses for the aluminum film upon request.
The latest of this range, introduced in 2022, is APYE L 50/150. It is built with aluminum sandwiched between 2 layers of PET, and a primer on the cell side. The effective thickness of this backsheet is 289 μm, with a reflectivity of 75%, and an ultra-low moisture ingression of 0.005 g/m2/d. Given its thickness, the backsheet qualifies for 1,000 V systems. The product can be opted with different thicknesses of PET and primer, and with higher reflectance.
The company is offering 2 more similarly configured products with different thicknesses. With a thickness of 405 μm, AHDPYE SPV P is the thickest of the range, built using a primer as the inner layer, thus benefiting from thickness-related aspects such as a maximum system voltage of 1,500 V. It has a reflectivity of 82% on the cell side. The APYE L with 370 μm effective thickness comes with all the optional features of APYE L 50/150. The specialty 4th product of this series is APY150 CBKHR, which is based on a coating on the cell side and is mainly offered in black color with enhanced reflectivity in the IR band of up to 55%. All the products have a rated water vapor permeability rate of 0.005 g/m2/d.
In addition to the somewhat specialty products above, Coveme is offering 2 product lines as part of its standard offering, designed for 1,000 V and 1,500 V system voltage. In the latter segment, the company is offering 4 products, which all have a thickness of > 300 μm. HDPYE C and HDPYE C BKHR are 2 products built on the same composition of 2 PET layers, designed to be on the outer UV proactive layer and core layer and inner coating, and have nearly identical specifications with 2 primary differences – thickness and color. The HDPYE C has an effective thickness of 315 μm and is offered in both white and black. HDPYE C BKHR, on the other hand, comes with a thickness of 320 μm and is offered in black, still facilitating enhanced reflectance of up to 55%, while the white backsheet supports up to 75% reflectivity.
The other pair of products are based on a configuration that uses primer instead of coating. Bk HDPYE SPV L, introduced in 2020, is black on both the air and the cell sides and has a thickness of 370 μm. HDPYE SPV L also has a thickness of 370 μm and is offered in white or black on the outer side and only in white on the cell side. This backsheet is optionally offered with ‘super-high’ reflectivity above the given spec of 83%. The major difference between these primer-based products compared to their coating-based counterparts is that the former have better moisture barrier properties of < 1.8 g/m2/d versus < 2.5 g/m2/d for the latter.
Within the 1,000 V system voltage group, the company is again offering 4 products. One among these, PYE SPV-SPV L is Coveme’s best-selling product for 1,000 VDC. The company claims it has the best-quality price-performance ratio on the market. With an ultimate thickness of 295 μm, this backsheet has a moisture ingression level of 2.5 g/m2/d. The same backsheet is offered in an all-black variant called BkPYE SPV L, primarily promoted for BIPV applications. PYE SPV L 305 is the thicker variant of PYE SPV-SPV L. As the numerical part of its name indicates, this PET/PET/Primer composition has an effective thickness of 305 μm. However, Coveme characterizes this backsheet as ‘extra thick’ owing to the fact that it is promoted for 1,000 V system voltage applications. It has a water vapor permeability of 2 g/m2/d and 82% reflectivity.
PYE MONO L PLUS is another 1,000 V DC backsheet. Launched in 2017, it is based on a monolayer configuration in a non-transparent variant consisting of PET and primer films. It has a total thickness of 218 μm. This product has a relatively high water vapor permeability of 2.2 g/m2/d, but also a high reflectance of 90%. According to Coveme, this backsheet provides the best price-performance ratio.
An interesting product series from Coveme are not ‘backsheets’ technically. They are mainly promoted as a replacement for the glass front covers. Coveme has developed a so-called ‘hard coating’ applied on top of PET and primers on the cell side. According to Coveme, this product, which it refers to as ‘totally transparent,’ uses a new coating technology on the polymer stack, ultimately resulting in ‘superior’ UV, scratch and abrasion resistance that can compete with glass in a few applications. While these products were also featured in our previous survey, Coveme has slightly upgraded the specs for these frontsheets.
ClrFS PYE MONO is a 1,000 V frontsheet with a total thickness of 283 μm and a rated moisture ingression level of 2.5 g/m2/d. The ClrFS HDPYE is a thicker version with an effective thickness of 385 μm. The additional thickness is built up by adding an extra layer of PET on the air side, on which the ‘hard coating’ is applied. At this thickness, the backsheet apparently qualifies for a DTI of above 300 μm, and is thus rated with a 1,500 V partial discharge. This polymer laminate is also rated with low moisture ingression properties, given as 1.7 g/m2/d. These 2 frontsheets are rated with a breakdown voltage of 20 kV.
For more non-fluoropolymer offerings from Coveme, refer to the product description section of the report. The text is an excerpt from the latest TaiyangNews Market Survey on Backsheets & Encapsulation Materials 2024/25, which can be downloaded for free here.