| HS Code | 773189 |
| Thickness | 0.50 mm |
| Density | 0.96 g/cm³ |
| Melting Point | 65 °C |
| Melt Flow Rate | 18-35 g/10 min |
| Va Content | 28-33% |
| Light Transmittance | ≥ 90% |
| Crosslinking Degree | ≥ 75% |
| Volume Resistivity | ≥ 1 × 10^15 Ω·cm |
| Tensile Strength | ≥ 20 MPa |
| Elongation At Break | ≥ 450% |
| Peel Strength To Glass | ≥ 60 N/cm |
| Peel Strength To Backsheet | ≥ 40 N/cm |
| Pid Suppression | Pass |
As an accredited HIUV S201MT2 EVA Encapsulant Film,Rear Side,PID Suppression Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | HIUV S201MT2 EVA encapsulant film, rear side, PID suppression grade, supplied in sealed rolls. Quantity: 1 roll per package. |
| Container Loading (20′ FCL) | Loaded as palletized cartons in a 20-foot container, secured and protected from moisture, heat, and physical damage. |
| Shipping | Ship as rolls on sturdy pallets, wrapped in moisture-barrier packaging with desiccant. Store upright, avoid crushing, heat, and direct sunlight. Not classified as hazardous for transport under ADR/IMDG. Keep dry and handle with care to prevent film deformation during transit. |
| Storage | Store HIUV S201MT2 EVA encapsulant film in its original sealed packaging in a cool, dry, well-ventilated area. Avoid direct sunlight, high heat, and excessive moisture. Recommended storage temperature is 0–30°C with relative humidity below 60%. Keep rolls upright and protected from physical damage. Use within shelf life for optimal performance. |
| Shelf Life | Shelf life is typically 12 months when stored sealed, below 30°C, with humidity under 60% RH. |
Utility-scale glass-glass bifacial lines running PERC or TOPCon half-cut cells in 182 mm and 210 mm formats place HIUV S201MT2 on the rear side in direct contact with either a second AR-coated tempered glass sheet or a transparent backsheet. This position demands bulk volume resistivity above 1.0 × 10^14 Ω·cm after 1000 h damp heat per IEC 61215-2:2021 because negative string-to-ground potential drives sodium ions from the front glass toward the cell rear-side metallisation. Qualification for this segment is conducted under IEC 61215-1:2021, IEC 61730-1:2023, and IEC TS 62804-1:2015, with PID stress applied at -1500 V, 85 °C, 85% RH for 96 h. The rear film is pre-compounded with peroxide crosslinking initiator, silane coupling agent, and a sodium-ion immobilising package; the lamination operator does not meter additional additives, and the rear layer is used at 0.60 mm thickness, corresponding to 570 g/m² and 50–52% of the total encapsulant mass when paired with a 0.60 mm front-side EVA. Production lamination uses a dual-chamber membrane laminator with a 2.2 m × 4.4 m platen, 152 °C ± 2 °C platen setpoint, vacuum stage 300 s, press stage 600 s, and cure hold 900 s; batch-to-batch gel content is controlled to 82–87% by solvent extraction. Terminal products are framed or frameless 600–700 Wp glass-glass modules for fixed-tilt and single-axis tracker arrays; the rear-side film is transparent rather than white reflective because bifacial gain from rear irradiance would otherwise be lost. A high-humidity lamination floor exceeding 60% RH requires pre-drying of the roll because condensed moisture at the glass-EVA interface lowers silane adhesion and creates edge voiding.
Because roof-mounted glass-backsheet lamination bonds the rear-side EVA to a corona-treated PVDF/PET backsheet at the same time as it encapsulates rear cell string gaps, this dual interface creates a cure-uniformity risk when platen temperature gradients exceed 3 °C. Lamination is conducted on single-chamber oil-heated laminators at 148 °C ± 2 °C, with vacuum 240 s, press 600 s, and cure 720 s; the lower platen setpoint relative to glass-glass is selected to prevent PET backsheet shrinkage and EVA bleed at module edges. The rear film is used at 0.45 mm thickness (430 g/m²), representing 46–49% of the total encapsulant mass when the front EVA is 0.50 mm. Compliance is verified under IEC 61215-1:2021, IEC 61730-1:2023, and IEC TS 62804-1:2015; PID testing for 60-cell and 120-half-cell formats uses the same 96 h stress but the rear-side film must also pass adhesion after the 85 °C/85% RH damp-heat precondition because backsheet delamination is the dominant field failure in rooftop systems. The downstream process includes automated string layup, busbar soldering, backsheet positioning, and lamination; terminal products include 430–560 Wp residential and commercial rooftop modules with black PVDF backsheets for visual uniformity or white PET backsheets for commercial C&I arrays. Rolls stored at >60% RH require 4 h pre-drying at 40 °C before lamination; combining the film with amine-cured polyamide backsheet adhesion promoters is not recommended because amine species accelerate EVA chain scission and lower gel content at the backsheet interface.
| Downstream segment | Rear film thickness | Laminator platen setpoint | Vacuum/cure hold | Target gel content | Primary qualification standard |
|---|---|---|---|---|---|
| Utility glass-glass | 0.60 mm | 152 °C ± 2 °C | 300 s / 900 s | 84 ± 3% | IEC 61215-1:2021 |
| Rooftop glass-backsheet | 0.45 mm | 148 °C ± 2 °C | 240 s / 720 s | 82 ± 4% | IEC TS 62804-1:2015 |
| Floating PV | 0.60 mm | 150 °C ± 2 °C | 360 s / 1080 s | 85 ± 3% | IEC 61701:2020 |
| BIPV facade | 0.76 mm | 145 °C ± 2 °C | 300 s / 1200 s | 80 ± 5% | EN 12600:2002 |
| Agrivoltaic canopy | 0.45 mm | 150 °C ± 2 °C | 300 s / 900 s | 83 ± 3% | IEC 61215-2:2021 |
| Vehicle-roof curved laminate | 0.45 mm | 152 °C ± 1 °C | 300 s / 600 s | 84 ± 2% | IEC 61215-1:2021 |
In seawater-near floating arrays, sodium chloride aerosol ingress produces surface conductivity on the rear glass that is not present in land-based installations; the rear-side encapsulant must therefore retain high bulk resistivity and interfacial adhesion when the module is exposed to IEC 61701:2020 salt mist severity and IEC 61215-1:2021 damp heat. The film is laid as a 0.60 mm rear layer (570 g/m²) and accounts for 53–55% of the encapsulant mass when front EVA is 0.50 mm; the heavier rear layer extends moisture ingress path length and reduces electrochemical corrosion of rear glass scribe edges. Lamination uses a dual-chamber vacuum laminator at 150 °C ± 2 °C, vacuum 360 s, press 720 s, and cure 1080 s; the extended vacuum stage is specified because floating pontoon production halls often operate at 55–70% RH, and trapped water vapor at the rear glass-EVA interface causes bubble formation during pressurisation. PID qualification follows IEC TS 62804-1:2015 at -1500 V, 85 °C, 85% RH, 96 h, with power-loss acceptance criterion below 5%; published data for this specific S201MT2 configuration is limited, but the film’s PID-suppression mechanism relies on sodium-ion immobilisation rather than solely on electrical resistivity. Downstream production for floating arrays includes edge-seal butyl application, frame earthing, and 1500 V string connection; terminal products are 450–580 Wp glass-glass modules mounted on HDPE pontoons with tilt angles below 10°. A processing limitation is the incompatibility with uncleaned rear glass edges contaminated by cutting fluid; edge contamination below the EVA causes undercure and creates a chloride ingress channel after 6 months of cyclic wetting.
Building-integrated balustrade and spandrel modules subjected to EN 12600:2002 pendulum impact and EN 13501-1:2018 reaction to fire classification shift the rear-side encapsulant requirement from optical transmittance to long-term creep compliance under dead-load and edge-seal compatibility with structural silicone. In this segment the rear EVA is commonly laminated at 0.76 mm thickness (720 g/m²) as either a single heavy film or two stacked plies totaling 0.76 mm; the rear encapsulant represents 58–62% of total encapsulant mass when the front layer is 0.50 mm. Compliance is assessed under IEC 61730-1:2023 for creepage and material tracking, EN 12600:2002 for impact, and EN 13501-1:2018 for fire classification; additional optical and durability requirements are verified according to ISO 4892-2:2013 UV ageing and ASTM E313-20 yellowness index after 1000 h. The lamination process uses a flatbed silicone-membrane laminator at 145 °C ± 2 °C, vacuum 300 s, press 900 s, and cure 1200 s; the reduced platen temperature avoids thermal shock in heat-strengthened or chemically strengthened glass and permits the thicker EVA layer to flow into stepped edge profiles without excessive peroxide decomposition before full vacuum. Terminal products include frameless facade panels, balcony balustrades, spandrel infill panels with ceramic frit on the rear glass, and overhead skylight panels in non-structural configurations. S201MT2 is not a structural interlayer; where building codes require overhead glazing to resist post-breakage retention under EN 12600, a separate PVB or ionomer structural interlayer must be laminated within the glass build-up, and the EVA layer must be considered only as encapsulant, not as the primary safety-glass interlayer.
For agrivoltaic canopy systems, rear-side irradiance from reflected albedo and diffuse light passing through module gaps is exploited for crop growth; this imposes a requirement that the rear-side EVA remain optically stable under intermittent rear UV exposure while maintaining PID suppression at high system voltages. The film is used as a 0.45 mm clear rear layer (430 g/m²) and accounts for 48–50% of total encapsulant mass in a symmetric front/rear 0.45 mm glass-glass layup. Standards applicable to this segment include IEC 61215-1:2021, IEC 61730-1:2023, IEC TS 62804-1:2015, and IEC 61215-2:2021 UV preconditioning at 15 kWh/m²; because crop canopies raise local relative humidity, the module rear surface may also be subjected to condensation cycling, so damp-heat adhesion retention is verified under 85 °C/85% RH for 1000 h. Production lamination uses a dual-chamber laminator at 150 °C ± 2 °C, vacuum 300 s, press 600 s, and cure 900 s; transparent rear glass with low-iron content and anti-reflective coating is used instead of opaque backsheets, and white reflective EVA formulations are avoided because they would block rear light transmission to crops. Terminal products are semi-transparent 200–350 Wp canopy modules with cell-free rear zones, greenhouse roof modules, and shading structures over berry or lettuce cultivation. The UV absorber package in the EVA must be verified by ASTM E313-20 yellowness index shift below 1.5 after 1000 h rear-side UV exposure; if the rear glass uses a textured anti-soiling surface, vacuum time must be extended by 60 s to prevent trapped air at the texture-EVA interface.
Vehicle-integrated modules with deep-curved rear glass expose the rear-side encapsulant to a narrow processing window because the film must fill cell steps and curved glass profiles without overflowing at the perimeter; the platen setpoint window is held to 152 °C ± 1 °C on the upper platen and 148 °C ± 1 °C on the lower platen, which is approximately 5 °C across the glass surface. The rear film is used at 0.45 mm thickness (430 g/m²) and represents 46–48% of the encapsulant mass when the front EVA is 0.50 mm; this thin rear layer minimises springback after lamination but still requires sufficient gel content to prevent creep at roof temperatures up to 95 °C. Qualification references IEC 61215-1:2021, IEC 61730-1:2023, and IEC TS 62804-1:2015; for automotive glazing components, additional optical and fragmentation requirements may be assessed under UN ECE R43 when the module replaces a glass roof insert. Production lamination for curved vehicle roofs uses a three-chamber vacuum laminator with membrane pressure 900 mbar, vacuum ramp 300 s, press 600 s, and cure 900 s; crosslinking kinetics are controlled by peroxide decomposition, with gel content reaching 84 ± 2% only if the film remains above 145 °C for at least 720 s. Below 140 °C, gel content remains below 70%, producing a creep-prone rear encapsulant that can flow into the module edge gap during thermal cycling; above 155 °C, the EVA melt viscosity drops sufficiently to cause bleed-out at the curved glass perimeter, reducing edge adhesion. Terminal products include curved solar roofs, vehicle tonneau covers, bus roof kits, and marine canopy panels with rear sputter-coated thin-film cells; for these products, the rear film must avoid acetic acid outgassing above 100 ppm at sustained 95 °C, because EVA thermal degradation releases acetic acid that can corrode sputter-deposited thin-film rear contacts and edge-seal butyl. A specific incompatibility is the combination with copper-indium-gallium-selenide rear contacts without a silicon nitride barrier, because moisture ingress through the EVA under 85 °C/85% RH can promote galvanic corrosion at the scribed cell edge; published data for this exact configuration with S201MT2 is limited, so a module-level damp-heat validation at 1000 h is mandatory before production release.
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HIUV S201MT2 EVA Encapsulant Film is classified as a rear-side ethylene-vinyl acetate encapsulant formulated for photovoltaic module lamination. The designation PID Suppression Grade refers to a set of formulation and crosslinking characteristics that reduce leakage current and ion transport at the cell-to-backsheet interface under negative system bias. The film is typically supplied in roll widths of 1000 mm, 1100 mm, and 1350 mm and thicknesses of 0.45 mm, 0.50 mm, and 0.60 mm; exact packaging dimensions require confirmation against the manufacturer lot release. During lamination, the film undergoes peroxide-initiated crosslinking to form a three-dimensional poly(ethylene-co-vinyl acetate) network. Gel content after lamination is typically measured according to ASTM D2765-16 using xylene extraction. The product is intended for rear-side lamination in c-Si modules using glass-backsheet or glass-glass construction, where rear-side ion diffusion and acetic acid release are critical degradation variables.
The primary electrical failure mode addressed by this film is sodium migration from the front glass through the cell stack under negative potential. In IEC 62804:2015 system tests at 85 °C/85 % RH and 1000 V for 96 h, potential-induced degradation appears as localised shunting and reduced fill factor. Rear-side EVA formulations in the PID suppression class are specified with volume resistivity above 1×10^14 Ω·cm at 25 °C and 500 V DC when measured according to ASTM D257. The electrical stability is influenced by bulk ionic content, residual peroxide decomposition products, and the degree of crosslinking. A lower free-acetate concentration after lamination reduces the formation of acetic acid, which is a known factor in accelerating metallisation corrosion and surface conductivity.
Volume resistivity is not a fixed material constant; it changes with temperature, humidity, and electric field. For this reason, PID suppression grades are evaluated at both 25 °C and module operating temperatures up to 85 °C. Post-test power loss thresholds vary by module manufacturer; many qualification programs use 5 % power loss as a pass/fail criterion. In rear-side EVA formulations, the bulk resistivity value is meaningful only when measured on laminated film because moisture ingress during damp heat reduces resistivity by up to two orders of magnitude. The PID suppression grade is formulated to retain resistivity above 5×10^12 Ω·cm under 85 % RH at 85 °C after saturation, although published data for this specific configuration is limited and module-level testing is required. Production-scale electroluminescence after biased damp-heat exposure has shown that lot-to-lot variation in gel content below 75 % can increase the frequency of localised dark regions; therefore, rear-side film is routinely controlled to a minimum gel content of 80 % after lamination.
In glass-backsheet configurations, moisture ingress through the backsheet is higher than in glass-glass modules, but the rear-side encapsulant remains the dominant conduction path for leakage current at the cell rear surface. The film is positioned between the cell string and the backsheet or second glass sheet. It must compensate for surface irregularities in the cell interconnect ribbons. The melt flow index measured at 190 °C/2.16 kg according to ISO 1133-1:2022 is typically controlled to 20–40 g/10 min for rear-side grades to ensure ribbon encapsulation without voiding. In a lamination test using a five-busbar cell string, incomplete ribbon fill can occur if the melt flow index is below 15 g/10 min or if the initial heating ramp exceeds 8 °C/min; this is due to insufficient flow before crosslinking immobilises the polymer network.
For glass-glass modules, the rear-side film may be used with a transparent backside encapsulant, but the cell-rear interface still benefits from lower ionic content. The rear-side grade differs from front-side transparent EVA in that it does not require high UV transparency; instead, it is formulated for higher volume resistivity and lower sodium content. In double-glass configurations, the rear-side film can also be used adjacent to the rear glass to provide a low-conductivity layer behind the cell.
In production-scale single-chamber laminators, the rear-side film is placed directly on the cell string before backsheet layup. The cure profile is governed by the peroxide decomposition kinetics of the encapsulant; for common dialkyl peroxide initiators used in EVA, the half-life at 145 °C ranges from 4–8 min, requiring hold time sufficient to achieve at least 80 % gel content. A vacuum lamination cycle with platen temperature 145–155 °C and hold time 12–18 min under membrane pressure 0.08–0.10 MPa is typically used; actual cure must be adjusted based on the gel content curve and the thermal profile of the laminator. The film must be conditioned at 20–25 °C and relative humidity below 60 % for at least 12 h before lamination. If stored above 30 °C or above 60 % RH, the film may absorb moisture, leading to bubble formation during cure. Roll changes should be conducted in a dry environment because condensation on the film surface can cause visible delamination defects. Vacuum ramp rate should not exceed 50 mbar/min during the initial evacuation stage to prevent edge wrinkles and trapped air at ribbon intersections. Platen thermal uniformity better than ±2.0 °C across the heated area is required to avoid spatial variation in gel content; edge zones on large-format modules are particularly susceptible to under-crosslinking when platen temperature drops near the frame support. Batch-to-batch variation in gel content should be confirmed against the certificate of analysis; if lot-to-lot variation exceeds ±3 % absolute, the lamination profile may require adjustment. The film should be consumed within 6 months of manufacture when stored in the original sealed packaging at 25 °C or lower.
The table below lists representative material properties for rear-side EVA encapsulants of the PID suppression class; test values must be confirmed against the lot-specific certificate of analysis. Published data for HIUV S201MT2 in all listed properties is limited to manufacturer technical documentation, and the ranges shown are typical for the product class rather than guaranteed specification limits. When comparing suppliers, the test method and specimen conditioning must be identical; for example, volume resistivity values obtained under 500 V DC at 25 °C are not directly comparable to values measured at 1000 V or after 96 h damp heat. The adhesion values depend on the type of glass, the lamination profile, and the silane coupling agent; values below 50 N/15 mm after lamination are generally considered insufficient for module qualification according to IEC 61215-2.
| Property | Test Method | Representative Value | Notes |
|---|---|---|---|
| Thickness | ASTM D6988 | 0.45–0.60 mm | As supplied film |
| Density | ASTM D792 | 0.95–0.97 g/cm³ | At 23 °C |
| Melt flow index | ISO 1133-1:2022, 190 °C/2.16 kg | 20–40 g/10 min | Pre-crosslinking |
| Gel content after lamination | ASTM D2765-16 | 80–90 % | After standard lamination cycle |
| Tensile strength at break | ASTM D882 | 5–12 MPa | Pre-lamination film |
| Elongation at break | ASTM D882 | 300–600 % | Pre-lamination film |
| Volume resistivity | ASTM D257, 500 V DC | 1×10^14–5×10^15 Ω·cm | Post-lamination |
| Peel adhesion to glass | IEC 62788-1-4 | 50–100 N/15 mm | After lamination |
| Water absorption | ASTM D570 | <0.5 % | 24 h immersion |
The volume resistivity test under ASTM D257 uses a guarded electrode to reduce surface leakage; specimens should be conditioned at 23 °C/50 % RH for 24 h before measurement. Gel content by ASTM D2765-16 requires extraction in boiling xylene for 12 h; the sample must be weighed before and after extraction. Peel adhesion to glass according to IEC 62788-1-4 is often performed at 180° peel angle with a crosshead speed of 100 mm/min. Without these conditions, comparison between suppliers is not valid.
Formulation differences are measured primarily by gel content, free peroxide residue, and acetic acid release after damp-heat exposure. Standard front-side EVA often uses vinyl acetate content in the range of 28–33 wt% to achieve low light loss, whereas rear-side PID suppression grades may use similar or slightly lower vinyl acetate content to increase crosslink density and reduce chain mobility. The peroxide package is selected to produce a gel content above 80 % after lamination without excessive free peroxide. Free peroxide residue above 0.05 wt% after lamination can continue to generate volatile by-products during service, contributing to bubble formation and interfacial adhesion loss. Silane coupling agents are used to improve adhesion to glass and backsheet, but the type and concentration are balanced against ionic contamination. Some rear-side films for PID suppression use low-sodium raw materials and non-ionic additives to keep bulk conductivity low.
Acetic acid generation during damp-heat testing is monitored because acetic acid can catalyse corrosion of solder-coated copper ribbons and increase surface leakage current. In comparison with standard rear-side EVA, the PID suppression grade typically shows a shift in the volume resistivity versus temperature curve; at 60 °C, the resistivity may be one order of magnitude lower than at 25 °C, but the absolute value remains above 1×10^13 Ω·cm in formulations designed for PID suppression. The loss of adhesion after 1000 h damp heat at 85 °C/85 % RH is typically less than 20 % of the initial value for rear-side PID grades, but this depends on glass type and module construction. The film is not recommended for use as the only encapsulant in flexible modules or for applications requiring continuous service above 105 °C because the ethylene-vinyl acetate network softens and oxidative degradation accelerates. Combination with amine-based anti-corrosion additives is not recommended because basic species can neutralize acetic acid but also increase ionic mobility and interfere with silane coupling reactions. The film should not be stored adjacent to strong oxidizers or UV-curing systems because free radicals can initiate premature crosslinking in the roll.
Compliance is evaluated under the following standards and regulations. The module manufacturer is responsible for verifying the final laminated module against the applicable certification body requirements.
| Standard or Regulation | Scope | Relevance |
|---|---|---|
| IEC 61215-2:2021 | Module qualification | Mechanical load, damp heat, thermal cycling |
| IEC 62804:2015 | Potential-induced degradation | 85 °C/85 % RH, 96 h, 1000 V |
| ASTM D2765-16 | Gel content | Crosslinking QC |
| ASTM D257 | Volume resistivity | Electrical insulation |
| ISO 1133-1:2022 | Melt flow index | Incoming resin and lot control |
| REACH 1907/2006 | SVHC | Restricted substances |
| RoHS 2011/65/EU | Hazardous substances | Market access |
For production qualification, the module manufacturer should verify adhesion, gel content, and volume resistivity on first article samples using the test methods listed above. The lot-specific HIUV certificate of analysis should be archived for traceability.
