Applications of Sumitomo Chemical Nipoflex H4021 EVA in Industrial Manufacturing

Sumitomo Chemical’s Nipoflex H4021 EVA (Ethylene Vinyl Acetate copolymer) is widely integrated in specialized downstream industrial sectors for its balanced mechanical flexibility, clarity, and processing consistency. Below, we detail the key segments where this grade is selected by manufacturers for advanced material performance and process control.

1. Photovoltaic Module Encapsulation

EVA copolymers are critical as encapsulation materials in solar panel manufacturing, where consistent gel content and durability under UV exposure are mandatory. Nipoflex H4021 supports reliable lamination, high light transmittance, and weather resistance, matching global requirements for long-life PV modules. Manufacturers integrate this grade specifically at the lamination stage after cell placement to secure high output and module uniformity.

Industry compliance standards

• IEC 61215: Crystalline Silicon Terrestrial Photovoltaic Modules
• IEC 61730: PV Module Safety Qualification
• UL 1703: Standard for Flat-Plate Photovoltaic Modules and Panels
• REACH and RoHS directives (EU)

Typical usage ratio

• 0.40–0.52 kg per 72-cell module (representing 18–24% of the module’s total weight); precise sheet thickness (0.45–0.55 mm) adjusted by output power class and desired crosslinking density.

Downstream process integration

• Extrusion and pellet melting for cast film or sheet production
• Thermal lamination post solar cell stringing, with integrated cross-linking phase (140–155°C, 20–25 minutes)
• Vacuum compression between glass and backsheet materials on module assembly lines

Final product types

• Crystalline silicon PV modules (mono- and polycrystalline)
• Thin-film photovoltaic panels
• Bifacial solar modules

2. Shoe Sole and Footwear Components Manufacturing

EVA is a preferred ingredient in the compounding and injection molding of midsoles, outsoles, and comfort footbeds due to its cushioning, rebound, and processability. The Nipoflex grade allows formulators to balance shore hardness and foam uniformity, meeting specific demands in sports, leisure, and work footwear where anti-fatigue and durability metrics are quantified through industry testing.

Industry compliance standards

• ISO 20871: Footwear Outsoles Abrasion Resistance
• ISO 20345: Personal Protective Equipment—Safety Footwear
• REACH annex XVII (phthalate and heavy metal restrictions)
• GB/T 15107: China Rubber Shoes General Technical Requirements

Typical usage ratio

• Blended at 60–85% by weight with foaming agents (azodicarbonamide or sodium bicarbonate), fillers, and colorants. Ratio adjusted for required density (0.2–0.4 g/cm³) and rebound elasticity specifications.

Downstream process integration

• Mixing with crosslinking, blowing, and color masterbatches in high-shear mixers
• Sheet extrusion followed by steam or hot-mold foaming (90–130°C)
• Direct injection into sole molds for forming and vulcanization

Final product types

• Running and athletic shoe midsoles
• Leisure and sandal outsoles
• Industrial safety boot insoles
• Children’s lightweight shoes

3. Hot Melt Adhesives for Packaging and Lamination

The controlled melt viscosity and transparency of this EVA variant make it valuable for precision hot melt adhesive production, particularly for packaging, bookbinding, and film lamination. Its formulation compatibility influences final tack, setting time, and bond strength in continuous high-speed packaging lines, especially where food-contact materials must maintain compliance across jurisdictions.

Industry compliance standards

• FDA 21 CFR 175.105: Adhesives for Food Packaging
• EN 12316-1: Adhesives for Paper and Packaging
• China GB 9685: Additives in Food Contact Materials (adhesives)
• ISO 9001 for in-plant quality management

Typical usage ratio

• 15–40% by weight of hot melt adhesive base, balance consisting of tackifiers, waxes, and stabilizers. Adjusted for open time (5–45 seconds) and viscosity targets.

Downstream process integration

• Compounding with hydrocarbon resins, waxes, and antioxidants in twin-screw extruders
• Pelletization or pastillation for bulk packaging
• Melter-based feeding into slot, spray, or bead applicators on packaging lines (120–180°C application temperature)

Final product types

• Carton sealing adhesives
• Bookbinding glue for hardcover or softcover bindings
• Paper-to-film and film-to-film lamination adhesives
• Food tray and flexible pouch sealing adhesives

4. Wire and Cable Insulation Compounds

Wire and cable producers choose this EVA copolymer for its electrical insulation properties, mechanical strength, and process flow, especially for medium-voltage and low-smoke, halogen-free cable jackets. By using Nipoflex H4021 during compounding, compounders maintain critical insulation thickness, dielectric properties, and consistent extrusion performance, aligning with mandatory fire safety and materials directives in multiple markets.

Industry compliance standards

• IEC 60502-1: Power Cables with Extruded Insulation
• UL 2556: Wire and Cable Test Methods
• EN 50267/EN 61034: Halogen-Free Cable Requirements (Low-Smoke Zero-Halogen)
• RoHS 2011/65/EU: Restriction of Hazardous Substances

Typical usage ratio

• 30–65% by weight of compound blend, depending on the cable voltage grade and flame retardant content; lower end for signal and control cables, higher end in low-voltage power cable sheathing with high filler loadings.

Downstream process integration

• Dry blending with magnesium hydroxide or aluminum trihydrate flame retardants, fillers, pigments, stabilizers
• High-temperature extrusion onto copper or aluminum conductors (140–185°C)
• Cross-linking (by peroxide or silane) if higher performance required

Final product types

• Medium- and low-voltage power cables
• Low-smoke, halogen-free data and control cables
• Automotive wiring harnesses
• Electric appliance cords

5. Films for Agricultural Greenhouse Coverings

EVA grades formulated for agricultural films deliver specific light diffusion, mechanical flexibility, and anti-fog properties, critical in multi-layer greenhouse covers. Formulators introduce this resin for its weather resistance and cling effect, ensuring durability under year-round UV exposure and microclimate control. Consistent quality facilitates advanced blown film lines with co-extrusion capability.

Industry compliance standards

• EN 13206:2001 – Plastic Films for Agricultural Use
• ISO 4892 – UV Resistance Testing
• China GB/T 8410 – Light Transmittance for Plastic Films
• SGS/ISO 14001 for environmental compliance

Typical usage ratio

• 10–30% by weight of final film layer composition, balanced with LDPE/LLDPE and light stabilizer masterbatches; adjusted to target haze levels (50–85%) and tensile strength requirements.

Downstream process integration

• Direct pellet feeding into multi-layer blown film extruders
• Co-extrusion with UV absorbers and anti-drip agents at 160–200°C
• Post-production corona treatment for surface energy enhancement as required

Final product types

• Greenhouse roof and side wall films
• Tunnel covering films
• Thermal insulation agricultural sheets
• Mulch and seedbed protection films

6. Flexible Packaging Foams and Protective Sheets

Converters use EVA-based foam for manufacturing flexible protective packaging, sports padding, and specialty insulation where compression set and impact attenuation are tightly specified. Selected Nipoflex grades provide stable cell structure, custom density, and slip characteristics required for automated die cutting on continuous fabrication lines.

Industry compliance standards

• ISO 845: Foam Plastics—Apparent Density
• EN 13432: Requirements for Packaging Recoverable through Composting
• RoHS compliance for electronic packaging
• REACH restrictions on specific additives

Typical usage ratio

• Base foam composition includes 65–95% EVA (by weight), adjusted according to target thickness (2–18 mm) and required resilience; lower loading for more rigid products, higher for cushioning pads.

Downstream process integration

• Physical or chemical foaming in batch mixer with activators and blowing agents
• Block foaming, slicing to sheets or rolls, and heat laminating for multilayer construction
• Waterjet or die cutting into custom shapes

Final product types

• Consumer electronics packaging foams
• Sports mats and pads
• Protective sheet rolls for delicate goods shipping
• Shock absorbing inserts in equipment or tool cases