Applications of Sumitomo Chemical Sumitate KA-31 EVA in Industrial Manufacturing

Sumitate KA-31 EVA, a specialty ethylene-vinyl acetate copolymer, finds critical use in a range of industrial manufacturing fields requiring well-defined mechanical, adhesive, and processing properties. We manufacture KA-31 EVA with controlled polymer characteristics to support commercial-scale formulations where process reliability, traceability, and global quality compliance are vital.

1. Photovoltaic Encapsulant Film Production

Solar cell module manufacturers rely on KA-31 EVA resin for the encapsulation layer due to its precise melting behavior and stable transparency under UV exposure. Processors select KA-31 EVA in film extrusion and lamination operations to produce encapsulant sheets with tailored crosslink density, enabling protection of PV cells from moisture while ensuring electrical insulation. Films require strict control of gel content, non-yellowing properties, and lamination adhesion to meet warranty and regulatory commitments to end users deploying solar panels in varying climate zones.

Industry compliance standards

• IEC 61215 (Crystalline silicon terrestrial PV modules – Design qualification and type approval)
• UL 1703 (Flat-plate photovoltaic modules and panels)
• RoHS Directive 2011/65/EU
• REACH Registration (EC 1907/2006)

Typical usage ratio

• Encapsulant layer: 90–100% KA-31 EVA, with 0–10% crosslinking additives or UV stabilizers based on cell type and module structure

Downstream process integration

• Film extrusion (twin-screw extrusion)
• Calendering into sheets (350–550μm)
• In-line addition of crosslinking agents before lamination
• Thermal lamination of sheets onto solar cells prior to module encapsulation

Final product types

• Photovoltaic panel encapsulant films
• Backsheet-interfaced protective films
• Thin-layer laminated PV modules
• Flexible and rigid solar panel assemblies

2. Hot Melt Adhesives for Packaging and Bookbinding

Industrial adhesive formulators incorporate KA-31 EVA as a key polymer backbone in hot melt adhesive (HMA) systems used for commercial carton sealing, case forming, and book spine gluing. This resin delivers controlled viscosity, rapid set speed, and bond flexibility at application temperatures of 110–160°C, balancing flow and tack. Manufacturers depend on its low extractables and stable aging to meet commercial food packaging safety requirements and maintain adhesive performance throughout supply chain conditions.

Industry compliance standards

• FDA 21 CFR 175.105 (Adhesives for indirect food contact)
• EU Framework Regulation EC No. 1935/2004
• ISO 22000 (Food safety management)
• BS EN 923:2015 (Adhesives – Terms and definitions)

Typical usage ratio

• HMA formulations: 25–40% KA-31 EVA, adjusted with tackifiers, waxes, and antioxidants based on target open time and substrate adhesion

Downstream process integration

• Hot melt compounding (heated blending with additives)
• Pelletizing or block molding of HMAs
• On-site heating and application using industrial glue applicators
• Pressure bonding to paperboard, plastics, or textiles in automated lines

Final product types

• Hot melt adhesives for food packaging
• Bookbinding glues
• Carton and case sealing HMAs
• Consumable blocks or pellets for end-user application equipment

3. Foam Shoe Sole and Midsole Manufacturing

Shoe manufacturers select KA-31 EVA as the main polymer for foam compound preparation for footwear midsoles and comfort insoles. Its precise vinyl acetate content allows tuning foam resilience, compression set, and elongation to meet performance targets from athletic footwear to safety work boots. Formulators rely on our tight particle size and purity controls, reducing defects in foam expansion and enhancing color and durability over the product lifecycle in accordance with end-market needs.

Industry compliance standards

• ISO 20871:2018 (Footwear – Test methods for outsoles)
• EN ISO 20345 (Personal protective equipment - Safety footwear)
• SGS restricted substances protocols (Footwear and leather goods)
• REACH Annex XVII (Limits on hazardous substances in consumer products)

Typical usage ratio

• Foam sole blends: 50–70% KA-31 EVA, with adjusters for blowing agents, fillers, and crosslinkers based on target foam density and mechanical tests

Downstream process integration

• Mixing and mastication in high-shear mixers
• Batch or continuous extrusion foaming
• Mold injection or compression molding into shape
• Post-cure treatments to stabilize foam structure

Final product types

• Midsoles for athletic and casual shoes
• Shoe insoles (custom and mass produced)
• Shock-absorbing components for work boots
• Specialty padding for orthopedic footwear

4. Wire & Cable Insulation Compounds

Wire and cable insulation compounding operations deploy KA-31 EVA to achieve flexibility, electrical resistance, and environmental durability required by low-voltage, data, and automotive wire products. Formulators combine our material with flame retardant fillers and specific plasticizers to reach passing grades for vertical burn and smoke density while maintaining extrusion consistency and surface finish, supporting reliable line speeds and reproducible cable geometry in continuous manufacturing.

Industry compliance standards

• UL 62 (Flexible cords and cables)
• IEC 60332 (Tests on electric and optical fibre cables under fire conditions)
• RoHS Lead and phthalate restrictions
• CSA C22.2 No. 49 (Flexible cords and cables, Canadian requirements)

Typical usage ratio

• Insulation compounds: 35–60% KA-31 EVA, with flame retardants and stabilizers at ratios set by jacket thickness, flexibility, and ignition resistance requirements

Downstream process integration

• Dry blending followed by melt-compounding with additive suite
• Strand pelletizing of insulation granules
• Extrusion coating directly onto metallic conductors (single screw or tandem extrusion lines)
• Cooling, winding, and in-line QA inspection for dimensional control

Final product types

• Building wire insulation
• Automotive cable jackets
• Flexible power cords
• Data transmission cables with enhanced flame resistance

5. Film Applications for Flexible Packaging

Converters in food and medical packaging integrate KA-31 EVA into blown and cast film production for pouches, flexible lids, and co-extruded multilayer films. This grade supplies precise melt index for low-temperature sealing, anti-blocking, and clarity control, making it essential for packaging lines requiring low seal-initiation temperatures and regulated migration limits. Our manufacturing approach supports tight batch-to-batch reproducibility, protecting both package security and automated form-fill-seal efficiencies in demanding downstream operations.

Industry compliance standards

• FDA 21 CFR 177.1350 (Ethylene-vinyl acetate copolymer resins)
• EU Regulation (EU) No 10/2011 (Plastic materials for food contact)
• GMP Regulation (EC) No 2023/2006
• ISO 11607 (Packaging for terminally sterilized medical devices)

Typical usage ratio

• Sealant layer in multilayer film: 10–30% KA-31 EVA, with main substrate of polyolefins; ratio set by required seal strength and film gauge

Downstream process integration

• Dry blend with other polymers (LDPE, LLDPE, polyamide)
• Blown or cast film extrusion
• Lamination with adhesives for multilayer structure
• Slitting and converting into finished reels for packaging lines

Final product types

• Food pouch sealant films
• Medical device wrapping films
• Resealable lids for dairy products
• Vacuum packaging for perishable goods