POE: HANGZHOU FIRST has developed a POE-based encapsulant series called TF4N, featuring a blocking ion mobility function. The details were presented by Stephen Tang, senior engineer at HANGZHOU FIRST during the TaiyangNews Cell & Module Production Equipment & Processing Materials Conference (watch presentation here). In addition to being effective for glass-glass modules, the company further emphasizes its products as also suitable for glass-backsheet configuration. When TF4N is used as the front encapsulant, the choice of rear encapsulation material becomes less critical, allowing even EVA to be used, according to the company. Additionally, the use of TF4N POE on the front eliminates the need for low WVTR backsheets. At the TaiyangNews Solar Technology Conference India 2025, InYoung Suh, Director of Business Development at Hangzhou First, will deliver a presentation on encapsulant materials and solutions for advanced solar cells and modules.
EPE: The majority of TOPCon producers are, however, increasingly adopting EPE encapsulants on both sides of the module. In addition to its cost effectiveness, EPE offers performance comparable to POE while providing superior processability. Unlike pure POE, which has certain drawbacks such as longer processing times and surface slipperiness, EPE supports higher productivity. Every leading encapsulant supplier is offering an EPE configuration for TOPCon. HIUV is one of the early developers of EPE. Jitin Rai Khanna, global sales director for HIUV, presented the company’s comprehensive solutions for TOPCon technology at the TaiyangNews High Efficiency Solar Technologies Virtual Conference. Khanna says the company’s EPE film is designed to meet the encapsulation requirements of all TOPCon cell architectures. The company optimizes the formulation of encapsulant additives to enhance the product's anti-PID polarization performance. The POE layer in the EPE structure is strengthened to prevent lamination bubbles effectively. The mixed sealing process of POE with EVA requires no additional padding on the edges, achieving a lamination yield of up to 100%. Already in mass production, this product has been validated by customers for its superior reliability, says Khanna. He adds that the product’s reliability is further demonstrated by passing industry tests, including PID 192 and DH2000.
Alongside its EPE film, HIUV has introduced a new product called P507S, which offers similar performance to pure POE films while reducing the amount of POE resin used. This co-extruded so-called EXP film, consisting of a structural strengthening layer between the POE and EVA layers, is designed to lower production costs and improve manufacturing efficiency, providing a cost-effective alternative to pure POE encapsulants without compromising performance. Endurans emphasizes that EPE still carries forward a part of the cost aspects of POE and is still prone to acid formation. It has developed a proprietary EPE configuration to replace the POE core layer with a low-cost and higher barrier and high melting PO film.
Imco Goudswaard, Commercial Manager & Sustainability Lead at Endurans Solar, presented the product details at the TaiyangNews Reliable Solar PV Module Design 2024 Conference. The film has superior moisture and electrical barrier properties, along with reduced acid formation properties. The film itself is much stiffer and has a lower shrinkage rate which eases handling and processing. In addition to lowering the costs, the film also supports sustainability, as the core layer is not crosslinked, making it easier to recycle at the end of a module’s life. Goudswaard showed the results of different testing protocols for the company’s EPE product, which showed a 40% reduction in water vapor transmission compared to conventional encapsulants, apart from reduced acid formation. Its improved moisture barrier properties have also been shown to reduce PID. The film also displayed good adhesion retention despite having a non-crosslinking core. Optical testing under prolonged UV exposure confirmed the encapsulant’s stability, with no significant loss in transmission after 5,000 hours of UV exposure (see Cost-effective & Reliable Coextruded Polyolefin-Based Encapsulation Solutions).
