Applications of Formosa Plastics TAISOX 7670S EVA in Industrial Manufacturing

Formosa Plastics TAISOX 7670S EVA is specifically produced for precise industrial requirements, with controlled VA content and melt flow features. It enables compounders and processors to achieve strict specifications in targeted manufacturing sectors. Below, we outline major downstream applications with detailed compliance, formulation, technical integration, and end product information based on real-world industrial practice.

1. Photovoltaic Encapsulant Film Production

High-clarity and crosslinkable EVA resins are essential for solar encapsulant films, as they protect photovoltaic cells against humidity and UV degradation. Manufacturers blend TAISOX 7670S EVA with curing agents and specific UV absorbers. Extrusion and lamination lines require consistent resin quality to maintain cell efficiency and durability, with end films calibrated for clarity and adhesion during module lamination. The resin’s VA content and flow properties allow controlled melting and crosslinking, supporting mass module assembly for both crystalline and thin film solar panels.

Industry compliance standards

• IEC 61215: Terrestrial photovoltaic (PV) modules—Design qualification and type approval
• UL 1703: Flat-Plate Photovoltaic Modules and Panels
• EN 61730: Photovoltaic module safety qualification
• RoHS Directive 2011/65/EU

Typical usage ratio

• 89–92% of total compound by weight; precise range set by film thickness, degree of crosslinking, and UV package requirements.

Downstream process integration

• Granule feeding into twin-screw extrusion line, melt blending with crosslinkers and stabilizers, continuous sheet extrusion, chill roll casting, and in-line film slitting.

Final product types

• Photovoltaic encapsulant films for solar cell module lamination
• Backsheet adhesion layers
• Frame sealant strips for PV assemblies
• Low iron tempered glass-laminated solar panels

2. Hot Melt Adhesive Formulation

EVA copolymers serve as a flexible polymer base for industrial hot melt adhesive (HMA) formulations. Compounders select TAISOX 7670S grades for rapid melting, good wetting on substrates like paper, wood, or fabric, and compatibility with micronized waxes and tackifiers. The final adhesive pellets must meet storage stability and rapid set-up time on automated lines. Adjusting the ratio of EVA in the formulation tailors adhesive softness and open time, optimizing performance for high-speed packaging and assembly processes.

Industry compliance standards

• FDA 21 CFR 175.105 (Adhesives for indirect food contact in packaging)
• ASTM D4497: Standard for Hot Melt Adhesives
• ISO 9001:2015 (production quality management systems)
• REACH Regulation (EC) No 1907/2006

Typical usage ratio

• 30–40% of adhesive compound; specific amount depends on tackifier and wax loading, as well as target softening point and viscosity for automated application guns.

Downstream process integration

• Polymer feeding in heated mixers, batch or continuous compounding, granulation or block molding, followed by cooling and packaging in pellet or slug forms for direct industrial use.

Final product types

• Case and carton sealing adhesives
• Bookbinding glues
• Product assembly adhesives in consumer electronics
• Pressure-sensitive adhesive tapes and label stock

3. Wire and Cable Sheath Compounding

EVA-based cable sheath compounds require precise control of flexibility, electrical insulation, and flame retardancy. The resin’s melt flow properties and compatibility with mineral fillers and fire retardant systems make it suitable for cable jacketing in power, control, and telecommunication applications. Compound designers use this resin with magnesium hydroxide or ATH, along with process aids, to comply with LOI and smoke emission tests, delivering final extrudates suitable for demanding environments.

Industry compliance standards

• IEC 60502-1: Power cables with extruded insulation and their accessories
• EN 50267-2-1: Halogen-free test methods
• UL 1581: Electrical wires, cables, and flexible cords
• RoHS Directive 2011/65/EU

Typical usage ratio

• 35–50% by weight in sheath compound; exact ratio set by filler content, flame retardant system, and cable flexibility grade required.

Downstream process integration

• Dry blending with flame retardants, twin-screw melt compounding, pelletizing, and direct feeding into cable extrusion lines for primary sheath fabrication.

Final product types

• Low-smoke, halogen-free (LSHF) wire sheaths
• Flexible insulation jackets for medium voltage and communication cables
• Control and signal cable jacketing for industrial applications
• Marine and shipboard cable sheathing

4. Footwear Injection Molding Compounds

The performance of unfilled EVA in foamed footwear soles and midsoles relies on grade purity and melt behavior. EVA grades such as 7670S are supplied with tightly controlled VA levels to create flexible, lightweight, and resilient soles when combined with foaming agents. Manufacturers optimize curing and expansion by varying the EVA share to achieve specific rebound and compression set values for athletics, safety, and casual shoes. Direct compounding and coloring is used on injection and compression molding lines to produce high-quality finished parts in large volumes.

Industry compliance standards

• ISO 20871: Footwear—Test methods for outsoles—Abrasion resistance
• GB/T 15107: Casual footwear technical specifications (China)
• REACH Regulation (EC) No 1907/2006
• Oeko-Tex Standard 100 (product safety for polymeric components)

Typical usage ratio

• 70–98% of formulation for single-density EVA soles; reduction possible with increased filler, colorant, or recycled content as required for density and hardness targets.

Downstream process integration

• Direct melt or pre-blended compound feeding to injection/compression molding machines, gas or chemical blowing agent addition, mold expansion, cooling, and demolding for shaped footwear parts.

Final product types

• Foamed midsoles and outsoles for sports shoes
• Slipper and sandal bases
• Die-cut orthotic or insole pads
• Antistatic or slip-resistant safety footwear components

5. Industrial Foam Sheet Fabrication

EVA copolymers, including the 7670S grade, provide controlled resilience and closed cell structure in industrial foam sheet production. These sheets are utilized in packaging, automotive, and construction. Precise blending and crosslinking during sheet extrusion and foaming assure dimensional stability and shock absorption. Manufacturers adjust the EVA’s blend ratio based on required density and flexibility, sometimes incorporating recycled scrap to achieve cost and performance objectives. Sheets are calendared, cut, and heat formed according to end-use dimensions.

Industry compliance standards

• ASTM D3575: Standard for Flexible Cellular Materials—Physical Testing
• EN 13501-1: Fire classification of construction products and building elements
• REACH Regulation (EC) No 1907/2006
• RoHS Directive 2011/65/EU

Typical usage ratio

• 68–95% in foam blends; reduction possible with fire retardants, color masterbatches, or additional softeners, as determined by density and compression set specifications.

Downstream process integration

• Compound extrusion with blowing/crosslinking agents, open roll calendaring, oven heat foaming, and in-line trimming or die-cutting for ready-to-convert foam sheets.

Final product types

• Shock-absorbing automotive interior foams
• Protective packaging sheets and tray inserts
• Thermal insulation foams for HVAC and building
• Sports and exercise mats