Applications of Sinopec Gulei EVA in Industrial Manufacturing

Sinopec Gulei Ethylene Vinyl Acetate (EVA) supports high-volume manufacturing across several specialized industries. As a polymer producer, we maintain strict control of resin properties to match downstream requirements. Below, we detail real-world application sectors with reference processing details, international standards, and industry product types.

1. Photovoltaic Encapsulation Films

EVA serves as the principal encapsulant in photovoltaic (PV) module production, ensuring cell isolation, stability, and light transmittance. Downstream processors compound EVA pellets with crosslinking agents and UV stabilizers, extrude into films, and perform lamination under high temperatures to achieve optimum cell sealing. Cell module producers require consistent polymer content and controlled melt index to fit automated film extrusion and module lamination equipment. Material QC focuses on gel content, haze, and thermal stability, as required by leading global energy standards.

Industry compliance standards

• IEC 61215 (Crystalline silicon terrestrial PV modules—Design qualification & type approval)
• UL 1703 (Flat-plate PV modules and panels)
• DIN EN 50548 (Photovoltaic connectors for use in DC systems)
• RoHS Directive 2011/65/EU for hazardous substances in electronic equipment

Typical usage ratio

• 65–80% EVA base resin in formulation; minor amounts of crosslinking/curing additives and UV absorbers balance the blend.
• Actual EVA proportion adjusts based on film thickness (typically 0.45–0.55 mm) and target crosslink density, set by end-user module requirements.

Downstream process integration

• EVA pellets blend with initiators and process aids.
• Extrusion or calendaring forms monolithic films.
• Lamination system applies heat and pressure to crosslink the film over solar cell assemblies.
• Post-lamination, finished modules undergo crosslink verification and optical testing.

Final product types

• PV encapsulant films (frontsheet and backsheet layers)
• Rigid c-Si PV panels for residential, commercial, and industrial installations
• Flexible and bifacial solar modules
• BIPV (building-integrated photovoltaics) laminates

2. Hot Melt Adhesive (HMA) Formulations

In modern adhesive manufacture, EVA acts as the main polymeric base for HMAs, delivering adjustability in bond strength, flexibility, and thermal response. Formulators combine EVA with tackifiers, waxes, plasticizers, and resins to meet packaging or woodworking application needs. Granule melt index, vinyl acetate content, and clarity control final HMA performance, particularly in automated high-speed gluing operations where consistency and low odor are critical.

Industry compliance standards

• FDA 21 CFR 175.105 (Adhesives for indirect food contact)
• REACH Annex XVII (Restriction of hazardous substances)
• ISO 9001-certified QA procedures for industrial adhesives
• ASTM D1876 (Peel resistance of adhesives)

Typical usage ratio

• 30–55% EVA copolymer as backbone; adjusted by required bonding profile and viscosity.
• Higher percentages for flexible packaging; lower for bookbinding or case/carton sealing.

Downstream process integration

• Blending in sigma blade mixers or melt kettles with process-controlled dosing.
• Sheet or pellet stock feeds into hot melt applicator systems (slot, spray, or bead application).
• Processors verify open/setting times and bond strength on selected substrates.

Final product types

• Hot melt glue sticks (industrial grade and manual application)
• Pressure-sensitive packaging adhesives for paper/boards
• Bookbinding spine glues
• Woodworking edge banding adhesives

3. Wire and Cable Insulation Compounds

EVA-based compounds serve as the insulating and sheathing layers in low- and medium-voltage cables. Formulators incorporate flame retardants and plasticizers into EVA feedstock to achieve electrical, flexibility, and fire-resistance properties that comply with telecom and utility-specific norms. Careful resin selection enables downstream cable extruders to optimize throughput rates and surface finish in high-volume continuous operations.

Industry compliance standards

• UL 1581 (Reference standard for electrical wires, cables, and flexible cords)
• IEC 60332-1 (Flame propagation tests on insulated wires and cables)
• RoHS Directive 2011/65/EU
• CSA C22.2 Canadian Electrical Code for cable insulation

Typical usage ratio

• 40–75% EVA in compound (by weight); adjusted according to target flexibility and flame retardancy.
• High vinyl acetate grades for extra flexibility in flexible cords; lower grades for stiffer sheaths.

Downstream process integration

• High-shear blending with flame retardants, antioxidants, fillers.
• Pre-compounding through twin-screw extrusion.
• Direct extrusion onto wire cores or as cable sheaths under controlled temperatures.
• Cooling, sizing, and print marking before final QA inspection.

Final product types

• Low-voltage power cable insulation and sheathing
• Flexible appliance cords
• Telecommunication cable jackets
• Fire-retardant data and signal cables

4. Foam Shoe Soles for Athletic and Casual Footwear

EVA granules are used as the base resin in physical and chemical foam molding processes for footwear midsoles and outsoles. Compounders select grades to meet resilience, density, and compression set requirements. Processors introduce foaming agents and colorants, then use autoclave or injection molding to produce high-cushion, lightweight soles. End-product quality is assessed through tests for abrasion resistance and dimensional stability, as mandated by international footwear guidelines.

Industry compliance standards

• EN ISO 20871 (Footwear—Outsoles—Abrasion resistance)
• SATRA TM77 (Compression set and resilience of footwear materials)
• REACH Annex XVII on footwear articles
• GB/T 15107 (Sports shoes general technical requirements)

Typical usage ratio

• 60–95% EVA (by weight) in shoe foam compound; varies with hardness and rebound targets.
• The ratio may decrease if blended with natural/synthetic rubber for specialty soles.

Downstream process integration

• Material blending with blowing agents, pigments, and minor additives.
• Closed-mold injection or compression foaming.
• Post-mold trimming, surface texturing, and inline QC for density and uniformity.

Final product types

• Sport shoe midsoles and outsoles (running, basketball, hiking)
• Slipper and sandal bases
• Orthopedic and safety shoe components
• High-cushion children’s footwear soles