The latest TaiyangNews Backsheets and Encapsulation Market Survey 2024 / 25 features product specifications from 17 companies, out of which 14 companies provided data for encapsulation materials. We have data for 9 products from HANGZHOU FIRST, the market leader in the encapsulation segment. All the products carried over from the last survey remain unaltered. The company lists 2 products in this EVA segment – S406 and S806 – both launched in 2021. The major difference between the 2 products is that S406 is a thicker film with a standard thickness of 500 μm with no UV cutoff, while S806 has a UV cut-off at 360 nm with a standard thickness of 450 μm. The 2 models have a standard width of 1,118 mm but can be opted for in a range of 200 to 2,200 mm. The rest of the specs for these 2 products are the same, and they also match one or the other product the company listed last year.
Su406 and Su806, both launched in 2017, have a density of 0.95 to 0.96 g/cm3. This product pair represents the company’s ‘superfast-cure’ range. That means the encapsulants support a faster cycle time in module manufacturing. While the recommended vacuum time during the lamination process with these 2 products is the same as that of fast-cure variants at 3 to 6 minutes, the press time is between 5 and 10 minutes, 1 to 5 minutes less than the fast-cure versions. These 2 models differ from each other in UV permeability; while the Su406 is totally UV transparent, the Su806 blocks light below 360 nm. The EVA sheets are rated with 12 Snail-trail resistance: F406PS and F806PS feature MPa tensile strength, while the rest of HANGZHOU FIRST’s EVA range is rated at 16 MPa (see Encapsulation Sector Balancing Innovation And Cost Pressures In Solar).
The remaining 5 listed products are part of the company’s fast-cure EVA range. Among these, the F806W model is somewhat distinctive in its application. Launched in 2015, it is a white EVA designed specifically for the rear side of the module. It helps reflect the sunlight that falls on the inter-cell spacing, giving it a second chance to get absorbed. It has a rated reflectivity of 90%, referring to a wavelength band of 400 to 1,100 nm. F806W comes with a standard thickness of 450 μm and 980 mm in width. It has an elongation of 400% in both the MD and TD directions and shrinkages of 5% and 2%, respectively. It has a glass adhesion strength of 60 N/cm and 40 N/cm for backsheets. The processing conditions are apparently the same as the other fast-cure products, as the EVA covering the rear of the module has to be co-processed with the one on the front side, as is the case with all of the ‘fast-cure’ models. The product is specially designed to avoid any overflow of white pigment to the front side during the lamination process.
Introduced in 2014, F406PS and F806PS are another pair of specialty products from HANGZHOU FIRST. The “PS” suffix denotes snail-trail resistance, while the differentiating factor among these 2 is the standard thickness and UV cut-off. While F406PS is supplied in a standard thickness of 500 μm and has no UV cut-off, F806PS is offered at 450 μm and stops sunlight below 360 nm from entering the module. These 2 EVA products are rated with an elongation of 450% in both TD and MD directions with respective shrinkages of 3% and 1.5%. These EVA films exhibit a > 60 N/cm glass adhesion strength and > 40 N/cm to backsheets. They also have the same chemical properties – a vinyl acetate content of 28% and 75% gel content. The specifications for mechanical and chemical properties are also the same for the company's entire product range, except for F806W. F406PS and F806PS are fast-cure versions that support similar processing conditions – a lamination temperature between 140 and 160°C, requiring a vacuum time of 3 to 6 minutes and a press time of 6 to 12 minutes (see Optimizing Encapsulation For Next-Gen Solar Modules).