HANWHA EVA 1326 Ethylene Vinyl Acetate Copolymer

Hot-melt adhesive compounding with HANWHA EVA 1326 is governed by the nominal vinyl acetate monomer content of 13 wt% and the melt flow rate of 26 g/10 min obtained at 190 °C under 2.16 kg load in accordance with ISO 1133-1:2022. In packaging, bookbinding, and carpet tile bonding formulations, the polymer is dry-blended with hydrogenated rosin esters or aliphatic C5 hydrocarbon tackifiers, Fischer-Tropsch waxes with congealing points in the 95–105 °C range, and 0.2–0.5 phr of a hindered phenol/phosphite stabiliser system. The 13 wt% vinyl acetate content provides polar interaction with cellulosic substrates without the severe low-temperature stiffening observed in high-ethylene-content copolymers, while the 26 g/10 min MFR allows the compounded adhesive to reach application viscosity of 800–2,500 mPa·s at 180 °C when measured with a Brookfield RVT viscometer using spindle 27 under ASTM D3236-88. Formulated adhesives are generally mixed in jacketed sigma-blade or vertical twin-screw systems at 150–180 °C; sustained residence above 200 °C accelerates deacetylation and releases acetic acid, which can corrode unalloyed steel and must be vented. The use of amine-based additives is avoided because acetic acid generated during processing can form amine carboxylates that increase viscosity drift and reduce adhesive clarity. In high-speed packaging lines, the open time is controlled by the wax-to-tackifier ratio, while hot tack and final fibre tear are equipment-dependent; published data for this specific EVA 1326 hot-melt configuration is limited and should be generated on the target substrate before qualification.

What Makes a 26 g/10 min EVA Grade a Viable Carrier for Filled Concentrates?

In additive masterbatch and mineral-filled concentrate production, EVA 1326 is specified as a wetting carrier because the 13 wt% vinyl acetate content increases the critical surface energy of the resin relative to LDPE and because the 26 g/10 min melt flow rate reduces melt pressure during dispersion. On a co-rotating twin-screw extruder with L/D 44:1, side feed port, and vacuum devolatilisation, carbon black loadings of 40–50 wt% are usually processed at melt temperatures 190–220 °C and screw speeds 400–600 min⁻¹. Filter pressure at a 100-mesh breaker plate is commonly maintained below 12 MPa, though published data for this specific EVA 1326 grade and carbon black surface area combination are limited. The EVA polarity assists dispersion of organic pigments and reduces agglomeration, but the relatively low vinyl acetate level means that polar interaction with aluminium hydroxide or magnesium hydroxide is weaker than with EVA grades containing 18–28 wt% vinyl acetate.

In film and moulding applications, the concentrate is diluted into LDPE, LLDPE, or polypropylene at 2–5 wt% addition levels; the carrier’s high MFR ensures rapid homogenisation in single-screw extruders with shorter L/D. Quality control laboratories should verify the as-received carrier MFR by ASTM D1238-23 at 190 °C/2.16 kg and compare pellet-to-pellet viscosity drift against ISO 1133-1:2022. Because the carrier is more sensitive to thermal degradation than LDPE, barrel temperatures above 230 °C must be avoided unless the formulation contains acid-scavenging dispersion aids; otherwise, deacetylation increases melt-phase acidity and plugs vacuum vents.

Blown Film Sealant Layer Modification and Melt Strength Considerations

Multi-layer blown film structures designed for frozen food packaging, lamination film, and form-fill-seal pouches use EVA 1326 as a sealant-modifying resin in LDPE-rich skin layers at 10–30 wt%. The lower melting point of the ethylene-vinyl acetate copolymer relative to LDPE reduces seal initiation temperature by approximately 10–15 °C when compared on films of equal sealant thickness and dwell time; heat seal strength is measured according to ASTM F88/F88M-23, while hot tack is evaluated by ASTM F1921. The high MFR of 26 g/10 min provides faster relaxation of oriented polymer chains at the seal interface, but it also reduces bubble stability during upward extrusion.

To maintain frost line stability, die gaps between 1.2 mm and 1.8 mm, blow-up ratios of 2.0–2.5, and extruder barrel profiles of 160–190 °C are typically selected. Increasing EVA 1326 concentration beyond 30 wt% can produce melt surging and web tension fluctuations, particularly on lines with internal bubble cooling. Pre-drying at 70–80 °C for 2–4 h is required when ambient relative humidity exceeds 60%, since surface moisture can create bubble defects and reduce seal consistency. Food-contact suitability must be confirmed under FDA 21 CFR 177.1350 and EU Regulation 10/2011; vinyl acetate specific migration should be verified when the final film is intended for aqueous or fatty food contact.

Crosslinked EVA foam sheet and moulded footwear components are produced with HANWHA EVA 1326 as a stiffness-modifying co-resin in blends containing 60–80 wt% of EVA grades with 22–28 wt% vinyl acetate. The 13 wt% vinyl acetate level of EVA 1326 raises hardness and improves dimensional stability of the moulded part, while the 26 g/10 min MFR reduces mixing viscosity and helps distribute azodicarbonamide blowing agent and dicumyl peroxide crosslinker without excessive shear heating. Two-roll mill compounding at 100–110 °C is followed by compression moulding at 150–160 °C under 15–20 MPa platen pressure; foam density in the 0.15–0.25 g/cm³ range is common for thermoformed packaging inserts and sport shoe sockliners.

When the EVA 1326 fraction exceeds 40 wt%, the resulting foam displays a measurable increase in hardness and a reduction in tensile recovery; compression set testing according to ISO 3386-1 and tensile property evaluation per ISO 1798 are used to determine the upper blend limit. Decomposition of azodicarbonamide and peroxide crosslinking overlap between 150 °C and 160 °C, so the mill must be equipped with tight roll clearance control to avoid premature scorch. Foam expansion is strongly dependent on mould venting and pressure release; batch-to-batch density variation is often caused by uneven heat transfer through the mould rather than by the base resin.

When Extrusion Coating Requirements Favour a High-MFI Ethylene Copolymer

Extrusion coating and lamination of paperboard, aluminium foil, and barrier films are modified by the addition of 5–15 wt% EVA 1326 to an LDPE-rich coating layer. The 26 g/10 min MFR at 190 °C/2.16 kg reduces melt pumping pressure and permits thin coatings of 12–15 µm at line speeds from 180–220 m/min, although published data for this exact grade in tandem extrusion lamination are limited and should be confirmed on the target line. Neck-in is reduced relative to low-density polyethylene of comparable melt index, while the vinyl acetate comonomer improves adhesion to oxidised aluminium foil and paperboard.

Barrel and adapter temperatures are normally held between 240 °C and 280 °C; prolonged exposure above 280 °C accelerates deacetylation, generates carbonaceous deposits in the die lip, and increases maintenance frequency. Extruder screws and dies should use corrosion-resistant metallurgy when EVA 1326 is processed continuously, and ventilation should be designed for dilute acetic acid off-gas. Peel strength of the coated structure is measured according to ASTM D903-98 for adhesive bond strength or ASTM F904 for flexible laminates, depending on the substrate.

Cast stretch film and cling layers intended for pallet wrapping and produce packaging incorporate EVA 1326 at 3–10 wt% in LLDPE-rich formulations to modify cling and puncture behaviour. In this application the high 26 g/10 min MFR acts as a viscosity reducer in the extruder, but the lower vinyl acetate content of 13 wt% limits the ultimate level of cling relative to higher-VA EVA grades; film processors therefore balance the EVA 1326 addition against cast roll temperatures, chill roll surface roughness, and corona treatment energy. Dart impact is measured by ASTM D1709-22, and machine-direction tear is evaluated by ASTM D1922-23; published data for EVA 1326 in this specific stretch film configuration remain limited.

Extruder barrel profiles for cast film with EVA 1326 are typically set at 180–220 °C, with rapid die lip cleaning required if the line is idle for more than 30 min because residual polymer can oxidise at the die exit. The grade should not be used above 10 wt% in cling layers where low modulus and high cling force are required; excessive EVA 1326 raises stiffness and reduces stretch retention.