| HS Code | 539013 |
| Product Name | KENGO WHITE EVA Film 40D Snow white opaque |
| Brand | KENGO |
| Material | Ethylene Vinyl Acetate (EVA) |
| Product Type | White opaque EVA interlayer film |
| Color | Snow white |
| Opacity | Opaque |
| Thickness | 0.40 mm (40D) |
| Density | 0.93-0.95 g/cm³ |
| Melting Point | 65-75 °C |
| Softening Point | 55-65 °C |
| Light Transmittance | ≤5% |
| Width | 1000-2500 mm |
| Length | 100 m/roll |
| Shelf Life | 12 months |
| Storage Conditions | 5-25 °C, dry, avoid direct sunlight |
As an accredited KENGO WHITE EVA Film 40D Snow white opaque factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | |
| Shipping | |
| Storage |
In monofacial crystalline silicon module lamination, the opaque white EVA film is positioned between the rear glass or backsheet and the cell array, where its reflectivity returns off-cell irradiance toward the front optical interface. This application is governed by IEC 61215-1:2021 for design qualification and IEC 61730-2:2016 for safety qualification, with film-specific optical and flow controls referenced to ASTM E903-20 and ISO 1133-1:2022. The formula addition rate is expressed as rear white encapsulant film thickness of 0.40–0.50 mm; one square metre of 0.45 mm film at a nominal density of 0.93–0.95 g/cm³ corresponds to approximately 420–480 g/m². The front transparent encapsulant and rear white film are commonly maintained at a 1:1 thickness ratio, adjusted according to cell spacing, ribbon geometry, and rear reflectivity. Downstream production uses a vacuum lamination chamber with oil-heated platens and a two-stage diaphragm cycle; the module stack is heated to 145–155°C at chamber vacuum below 100 Pa, held for 8–15 minutes, and transferred to controlled cooling at approximately -0.5 to -1.0°C/min until platen temperature falls below 50°C before edge trimming. If the film is formulated as a peroxide-containing crosslinkable encapsulant grade, gel content after lamination is controlled within 75–90% by solvent extraction against IEC TS 62788-2; incomplete cure below this range can produce creep failure during thermal cycling, while over-cure can release acetic acid that corrodes cell metallization. Published data for this specific film grade under photovoltaic lamination is limited; the process window should be confirmed by a mini-module lamination trial. The film should be stored at 15–25°C and below 60% RH; unwrapped film exposed to RH > 60% for more than 24 hours should be dried at 50–60°C for 4 hours before lamination because retained moisture can form bubbles under vacuum. The film should not be combined with amine-containing release liners or cleaning solvents, because amine residues can accelerate deacetylation and shift crosslinking behavior. The terminal product type is a monofacial photovoltaic module with an opaque white rear encapsulant; bifacial modules requiring rear-side transmission are outside the optical function of this film.
| Downstream scenario | Primary compliance standard | Key test method | Typical pass-line control |
|---|---|---|---|
| Photovoltaic white rear encapsulant | IEC 61215-1:2021; IEC 61730-2:2016 | ASTM E903-20 | Gel content 75–90% |
| Laminated safety glass | EN ISO 12543-2:2021; EN 14449:2005/AC:2005 | ASTM D1002-10 | Demolding at ≤40°C |
| Footwear upper lamination | REACH (EC) No 1907/2006 Annex XVII | ISO 11339 | Dwell 10–18 s |
| Automotive interior lamination | FMVSS 302; VDA 278 | Burn rate / VOC-FOG | Bond-line ±5°C |
| Print finishing lamination | EU 10/2011; 21 CFR 177.1350 | EN 1186-1 | Board moisture ≤8% |
| Medical lidding web | ISO 11607-1:2019 | ASTM F88/F88M-21; ISO 10993-5 | Seal fail mode cohesive |
Laminated safety glass production with this opaque white EVA interlayer is processed below the plasticizer-containing PVB autoclave threshold and permits lamination in a vacuum bag oven without a high-pressure autoclave cycle. The compliance framework for this downstream route is EN ISO 12543-2:2021 for laminated safety glass and EN 14449:2005/AC:2005 for factory production control; adhesion performance is routinely verified by ASTM D1002-10 on glass coupons and by fragmentation or penetration methods described in ANSI Z97.1-2015 (R2020). The formula addition ratio is defined by interlayer thickness within the glass stack: a single 0.38 mm white film is used between two lites of 3–6 mm annealed glass, or two layers totalling 0.76 mm are used when a higher impact category is required. One square metre of 0.38 mm EVA film at density 0.94 g/cm³ contributes approximately 357–365 g/m²; in a 3 mm/0.38 mm/3 mm stack the interlayer is approximately 5.9% of total glazing thickness, and in a 6 mm/0.76 mm/6 mm stack the interlayer is approximately 6.0%. The downstream process consists of vacuum bag lamination in a convection oven at 130–150°C for 45–90 minutes, with vacuum held at 0.08–0.09 MPa and controlled cooling to 40°C or below before bag release. Glass surfaces must be free of silicone release agents; a water-contact angle measured according to ASTM D5946-17 below 15° after cleaning is used as a practical pass-line control. Failure to cool below 40°C before demolding commonly produces edge delamination because residual thermoplastic modulus is insufficient to resist spring-back in the glass. The terminal product types are opaque decorative laminated safety glass panels, shower partitions, and interior doors where light transmission is intentionally blocked while retaining safety-glazing behavior.
This scenario is specific to heat-activated lamination of cut EVA film segments between textile quarter panels and injected EVA or rubber midsoles, where the white opaque film functions as both a bond-line spacer and a controlled colored backing layer. The compliance boundary for restricted substances in finished footwear is REACH (EC) No 1907/2006 Annex XVII, supplemented by brand-specific RSL limits that commonly follow SATRA TM31 or equivalent restricted substance guidance; peel strength of the fused assembly is screened by ISO 11339 for T-peel of flexible-to-flexible laminates. The addition ratio in this process is defined by film gauge rather than liquid weight: the white film is cut to 0.08–0.12 mm, corresponding to a dry film coverage of approximately 75–115 g/m². The downstream process uses a flatbed heat press with independently controlled upper and lower platens, a press force capable of maintaining 0.3–0.5 MPa across the cutting die, and a temperature set point of 105–130°C; dwell time is held to 10–18 seconds, followed by transfer to a water-cooled platen at 15–25°C for 10–15 seconds to freeze the thermoplastic interface. The critical failure mode is incomplete penetration of the film into the textile substrate when dwell time drops below 8 seconds or when platen pressure is uneven across the die; the white layer remains visually intact but the bond fails in subsequent flex testing. Substrates conditioned above 70% RH should be pre-dried at 45–55°C for 2–3 hours, because steam generated at the bond interface during the hot-press step can form pinholes in the opaque film. The film should not be fused directly against high-content PVC plastisol components without first verifying plasticizer migration resistance; plasticizer levels above 18–22 phr can reduce long-term bond strength. The terminal product types are athletic shoe quarters, tongue logos, and counter stiffeners where a controlled white backing is required.
On automotive interior trim lines, the opaque white EVA film is used as an extruded adhesive veil between a decorative PVC or PU skin and a polypropylene, ABS, or wood-fiber core. The governing compliance framework is FMVSS 302 for horizontal burn rate, with a finished-assembly acceptance limit of less than 100 mm/min, plus VDA 278 thermal desorption screening for volatile organic compounds and fogging mass. The formulation addition ratio is controlled by film thickness and core coverage: the film is supplied at 0.05–0.10 mm, equivalent to approximately 45–90 g/m², and is applied as a 100% coverage adhesive layer between the decorative skin and the structural substrate. The downstream process is a membrane press or vacuum-forming cell with a silicone bladder exerting 0.4–0.8 MPa at 130–160°C; heating time is 60–120 seconds, with bond-line temperature monitored by embedded thermocouple rather than inferred from heater set point alone. After lamination the assembly is transferred to a cooling fixture maintained at 20–30°C to prevent spring-back of the thermoplastic core. The main production failure mode is cold spots at the tool perimeter, producing edge peel when the film has not reached its melt flow temperature; process audits typically control bond-line temperature at the deepest draw point with a tolerance of ±5°C. The film is incompatible with mold-release residues containing fatty acid esters; core substrates should be cleaned or plasma-treated to a surface energy of 40–45 mN/m before lamination. When a soft PVC skin contains plasticizer above 30 phr, plasticizer migration can plasticize the EVA bond line and reduce lap-shear strength below the interior trim specification after thermal aging. The terminal product types are door panels, armrest caps, package tray substrates, and seat-back panels with an opaque white adhesive veil.
Thermal lamination of opaque white EVA film to printed paperboard is governed by the cooling path between the nip exit and the sheeting station, not solely by nip temperature. When the laminated sheet is destined for food-contact board, the finished laminate must comply with EU 10/2011 for plastics intended to contact food and with 21 CFR 177.1350 for ethylene–vinyl acetate copolymers; overall migration testing is performed under EN 1186-1 or equivalent. For non-food graphic arts applications, the compliance burden is usually limited to heavy-metal and phthalate restrictions under REACH (EC) No 1907/2006 Annex XVII and any referenced packaging or toy safety standard. The formula addition ratio is defined as film thickness to board weight: a 25–40 µm white opaque film is applied to 250–400 g/m² paperboard, producing a film-to-board weight ratio in the range of approximately 0.08–0.15. The downstream process uses a thermal laminator with a chrome-plated steel main roller and a rubber back-up roller; the film is preheated to 90–120°C, nipped at 2–6 bar, and advanced at 10–25 m/min through an S-wrap cooling unit with the first cooling roller held below 30°C. The measured production failure point is blocking and sheet curl when the web exits the cooling section above its glass transition range; sheets cut in-line before the surface reaches 30–35°C show edge lift and dimensional instability. The film should not be processed against board with moisture content above 8% because steam generated in the nip creates delamination blisters; board should be acclimatized at 23°C ±2°C and 50% ±5% RH for 24 hours before lamination. Terminal product types are book covers, menu covers, and opaque shelf-ready packaging where the white film replaces an additional white printing pass.
Sterile barrier lidding webs use an EVA sealant layer to achieve peelable heat seals on PETG or APET trays, and the opaque white grade serves as the visible seal indicator without solvent-borne coatings. The compliance framework for medical packaging is ISO 11607-1:2019 for packaging for terminally sterilized medical devices, with seal strength validated according to ASTM F88/F88M-21 and biological safety screened by ISO 10993-5 for cytotoxicity and USP <88> for biological reactivity where the end-use device requires it. The addition ratio in the converting step is the EVA sealant web thickness of 30–60 µm, equal to 28–56 g/m² when the EVA layer density is 0.93–0.95 g/cm³; seal width is typically 5–10 mm and is controlled by the die-cut lid profile rather than by a wet coating weight. The downstream process uses a reciprocating tray sealer or continuous form-fill-seal line with heated sealing bars at 120–160°C, dwell 0.5–2 seconds, and sealing pressure 3–6 bar; the seal bar profile is contoured to avoid thinning the film at the tray flange radius. The critical test after sealing is not only tensile seal strength but failure mode classification: acceptable production results show cohesive failure of the EVA web or delamination of the tray flange, while adhesive failure at the seal interface indicates surface contamination or incomplete heating. The operational boundary is sterilization compatibility; EVA-based seals should not be qualified for radiation doses above 50 kGy without dose-mapping and accelerated aging because oxidative chain scission can reduce peel strength below the documented minimum. The film should not be exposed to ketone or ester cleaning solvents before sealing because surface swelling can shift seal initiation temperature. Terminal product types are lidding films for PETG/APET sterile barrier trays, pouch overwraps, and form-fill-seal medical kits where a visible white sealant layer is required.
Competitive KENGO WHITE EVA Film 40D Snow white opaque prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615380400285 or mail to sales2@liwei-chem.com.
We will respond to you as soon as possible.
Tel: +8615380400285
Email: sales2@liwei-chem.com
Flexible payment, competitive price, premium service - Inquire now!
The KENGO WHITE EVA Film 40D Snow White Opaque is a pigmented ethylene-vinyl acetate encapsulant film supplied for photovoltaic module lamination. The product designation places the film in the white opaque high-reflectance EVA class, with the 40D identifier interpreted as a nominal thickness of 0.40 mm. It is not a Shore hardness grade or a melt-flow index. The film is intended for lamination layups in which the backsheet-adjacent encapsulant is not required to transmit light. Typical applications include monofacial glass/backsheet modules with white backsheets, cell-gap reflectivity recovery, and constructions where rear-side hiding power is specified. Roll width, slit tolerance, core diameter, splice count, and liner configuration are converter-defined and must be checked against the incoming material specification for each lot.
Compositionally, the base resin is an ethylene-vinyl acetate random copolymer. Photovoltaic EVA encapsulants commonly use a vinyl acetate content of 28–33 wt%. This range provides polar adhesion sites for glass and backsheet surfaces while limiting low-temperature stiffening. The white opaque formulation contains a mineral pigment system, typically rutile titanium dioxide or a titanium dioxide-containing masterbatch, plus a peroxide crosslinking agent, silane adhesion promoters, ultraviolet stabilizers, and antioxidants. The pigment increases melt elasticity and reduces melt flow. Melt flow rate measured on uncured film per ISO 1133-1:2022 at 190 °C under 2.16 kg is generally in the 20–35 g/10 min range for filled white EVA films, with lower values observed as pigment concentration increases. Because crosslinking begins at elevated temperature, melt flow rate is a raw-material and incoming-stability indicator rather than a lamination process predictor.
Film thickness is verified by mechanical scanning or optical profilometry according to ISO 4593. The nominal thickness is 0.40 mm, and the supplier tolerance is usually ±10% of nominal. Density of the white opaque EVA is higher than that of transparent EVA because of the dispersed mineral phase. Values measured by ISO 1183-1:2019 typically fall between 0.98 and 1.10 g/cm³, compared with 0.93–0.96 g/cm³ for unfilled transparent grades of equivalent vinyl acetate content. The higher density affects roll weight and material yield per square meter; module bill-of-materials calculations should use the supplier’s lot-specific density rather than a generic EVA value.
Optical performance of the snow white opaque film is specified primarily by reflectance and yellowness index rather than transmittance. Total luminous reflectance measured with hemispherical geometry per ASTM E1331 is typically greater than 88% over the 400–700 nm range for a 0.40 mm white EVA film. Direct luminous transmittance determined by ASTM D1003 is usually below 5%. Yellowness index according to ASTM E313 after lamination should remain below 2.0. Initial yellowness is less diagnostic than yellowness index change after damp heat because the white pigment masks early chromophore formation in the bulk. A film that appears visually acceptable after 1000 h at 85 °C/85% RH can still exhibit interfacial adhesion loss or acetic acid-induced corrosion; appearance alone is not a sufficient reliability indicator.
Uncured film tensile properties are relevant for layup handling and vacuum forming. White opaque EVA films of this class typically show tensile strength in the 10–20 MPa range and elongation at break in the 400–600% range when tested per ISO 527-3 or ASTM D882. The filled white grade may exhibit slightly lower elongation at break than transparent EVA because of pigment particle stress concentration. Shrinkage after unrestrained exposure at 150 °C for 30 min is generally below 2% when measured per ASTM D1204. Low shrinkage is necessary to prevent cell movement and edge contraction around cell strings during the early heat-up stage before crosslink density builds.
In production lamination, the film is assembled as glass / EVA / cell string / EVA / backsheet or rear glass and processed in an oil-heated vacuum press. The white opaque 40D grade is usually run with platen setpoints of 145–155 °C. Because the white pigment scatters infrared radiation, the backsheet-adjacent interface can lag behind the glass-side interface by 1–3 K under identical laminator settings. This thermal offset is a recognized production-scale difference between white opaque and transparent EVA. On single-chamber laminators, the effect is compensated by increasing soak time by 2–3 min when compared with transparent EVA of the same thickness. Double-chamber laminators with active cooling provide more uniform cure because the second chamber removes heat before panel unload and reduces crystallinity gradients.
The vacuum and pressure sequence is critical for void control. First-stage vacuum drawdown is commonly conducted at 30–50 mbar absolute, followed by membrane pressurization to 900–1100 mbar absolute. Total cycle time at 145–155 °C is commonly 14–18 min for monofacial modules. If the platen temperature remains below 140 °C, the gel content may fall below the required minimum and residual peroxide will remain in the encapsulant. Crosslink density is monitored by solvent extraction in xylene or toluene according to ASTM D2765-16. A minimum gel content of 70% after lamination is referenced in many module acceptance specifications. For white 40D film, gel content should be measured on both glass-side and backsheet-side specimens because the pigmented layer can create a cure front offset through the thickness. Mixed-sample testing can miss a low-cure backsheet interface.
Bubble formation is controlled by moisture content and vacuum sequencing. If the film is stored or handled at high relative humidity, water vaporizes during lamination and can nucleate bubbles at cell edges and string gaps. Moisture uptake above approximately 0.1 wt% is considered a production risk for EVA encapsulant films. Some production lines pre-dry exposed film at 40–50 °C for 4–8 h before layup when relative humidity has exceeded 60% for more than 24 h. Pre-drying is not a substitute for sealed storage; it is a corrective control for temporary exposure.
A comparative assessment against transparent EVA and polyolefin elastomer encapsulants is necessary for bill-of-materials selection. Transparent EVA with the same vinyl acetate range transmits 90–92% of visible light per ASTM D1003. The white opaque 40D transmits less than 5% and instead returns light from cell-gap regions toward the cell edges and front glass. The resulting module-level current gain depends on cell spacing, glass antireflection coating, backsheet reflectivity, cell edge geometry, and string layout. Published data for this specific KENGO configuration is limited; side-by-side lamination batches with identical cells and backsheets are required to confirm any performance difference. No uniform power-gain claim is applicable across all module designs.
UV-cut transparent EVA and white opaque EVA are not interchangeable optical strategies. UV-cut transparent EVA uses organic UV absorbers to suppress short-wavelength transmission while maintaining high visible transmittance. White opaque EVA relies on particulate scattering and hiding power. A white opaque EVA may still contain UV stabilizer packages to protect the polymer matrix from photo-oxidation. The scattering mechanism does not remove the need for matrix stabilization, particularly in high-UV deployment environments verified under IEC 61215-1:2021 UV preconditioning at 15 kWh/m² total UV irradiation.
| Property | Test method | Transparent EVA 28–33% VA | White opaque EVA 40D class | POE encapsulant |
|---|---|---|---|---|
| Luminous transmittance at 0.40 mm | ASTM D1003 | 90–92% | ≤5% | 90–93% |
| Total luminous reflectance | ASTM E1331 | 8–10% | ≥88% | 8–10% |
| Density | ISO 1183-1 | 0.93–0.96 g/cm³ | 0.98–1.10 g/cm³ | 0.86–0.90 g/cm³ |
| Melt flow rate, 190 °C/2.16 kg | ISO 1133-1 | 25–35 g/10 min | 20–30 g/10 min | 10–25 g/10 min |
| Gel content after lamination | ASTM D2765-16 | 70–85% | 70–85% | 60–80% if peroxide-cured |
The table values are representative of industrial EVA and POE encapsulant classes and are not a substitute for the manufacturer’s certificate of analysis for the KENGO 40D Snow White Opaque lot. Lot-specific values will vary with pigment loading, stabilizer package, and compounding conditions.
High white pigment loading can reduce available polar binding sites at the encapsulant–backsheet interface. Peel adhesion values for white EVA on polyvinyl fluoride-based or polyester-based backsheets are often in the lower half of the 40–120 N/cm range reported for EVA encapsulants under 180° peel testing. The exact value depends on backsheet surface energy, primer chemistry, lamination temperature, and gel content. Adhesion to glass is usually higher because silane coupling agents in the EVA formulation react with silanol groups on the glass surface. Incoming QC peel testing should use the specific glass and backsheet materials that will be used in production, not generic reference substrates.
Reflectivity and peel adhesion are coupled through film morphology. Pigment dispersion is controlled during compounding; undispersed titanium dioxide agglomerates can create local stress concentrations and interfacial voids. Production audits have observed that filler agglomeration correlates with lower backsheet peel force and with microvoids along cell edges after lamination. Some manufacturing lines use an optical microscopy limit of less than 0.1% undispersed pigment area on pressed films, but the acceptance limit must be verified against lot-specific data and failure analysis correlations.
When the white opaque layer is placed adjacent to a rear glass or transparent backsheet, its hiding power can mask backsheet discoloration. This is an optical consequence of high reflectance, not an independent reliability claim. In bifacial modules, the white opaque film is not appropriate for the rear-side transparent encapsulation layer because it blocks rear irradiance. In monofacial modules, the film is used only where rear-side transmission is not required.
Incoming quality control for the KENGO WHITE EVA Film 40D Snow White Opaque should include thickness mapping across the width, width tolerance, roll splice count, moisture content, melt flow rate, and lamination-derived gel content. Storage should be maintained at 5–30 °C and relative humidity below 60%. Rolls should remain in vacuum-sealed desiccant-containing packaging until immediately before use. Exposure to high humidity or direct sunlight can accelerate peroxide decomposition and moisture uptake. If the film has been exposed to relative humidity above 60% for more than 24 h, pre-drying at 40–50 °C for 4–8 h is applied on some production lines before layup. The film should not be frozen in a way that causes condensation upon thawing.
Compatibility limits are process-critical. Contact with amine-based surface primers or uncured silicone compounds can interfere with peroxide crosslinking and reduce gel content. The film is not intended for direct food-contact use. Regulatory declarations under REACH 1907/2006/EC and RoHS 2011/65/EU should be obtained from the supplier for each production lot when module certification requires material compliance. Long-term performance screening is conducted under IEC 61215-1:2021 damp heat at 85 °C/85% RH for 1000 h, humidity freeze, and thermal cycling. Yellowness index change per ASTM E313, gel content retention, and peel adhesion retention are recorded before and after exposure. The white opaque film masks bulk yellowing visually, so optical appearance alone must not be used as the sole acceptance criterion. Each incoming lot of KENGO 40D Snow White Opaque should be gated against supplier certificate values and the module maker’s incoming QC limits before release to the lamination floor.
