HANWHA EVA 1519 (em inglês)

HANWHA EVA 1519 is an ethylene-vinyl acetate copolymer grade with a nominal vinyl acetate content of 15 wt% when determined by ISO 8985:1998 and a melt mass-flow rate of 1.9 g/10 min when measured at 190°C under a 2.16 kg load according to ISO 1133-1:2022. The manufacturer-reported density is 0.938 g/cm³ when tested to ISO 1183-1:2019. These values position the grade between 13 wt% vinyl acetate types such as EVA 1315, which offer higher crystallinity and lower polar adhesion, and 15 wt% vinyl acetate grades with melt flow rates above 2.5 g/10 min, which offer easier injection molding but reduced melt strength. Tensile strength at break is approximately 18 MPa and elongation at break approximately 700% when tested to ISO 527-2:2012, with Shore D hardness of 44 measured by ISO 868:2003. These are representative technical data sheet values, not release limits.

What Limits Thermal Stability and Additive Compatibility in EVA 1519 Processing?

Thermal degradation in EVA 1519 proceeds by ester pyrolysis of the vinyl acetate side groups, releasing acetic acid and forming conjugated unsaturation in the polyethylene backbone. Sustained melt temperatures above 200°C initiate measurable acetic acid evolution, and degradation accelerates sharply above 230°C. Production-scale single-screw extruders with screw diameters of 65 mm and L/D ratios of 28:1 therefore maintain die-lip melt temperatures between 175°C and 205°C to reduce gel formation and chrome-plate plate-out. The grade is incompatible with primary amines and strong alkalis, which catalyze ester hydrolysis and can produce premature crosslinking, discoloration, and low-molecular-weight volatiles. Screw designs with compression ratios from 2.5:1 to 3.0:1 and barrel zones using reverse temperature profiles limit melt residence time. After processing, a purge with low-density polyethylene is required before shutdown because EVA 1519 held at melt temperature for more than 30 min can deposit carbonaceous residue on screw flights and barrel walls.

Closed-cell crosslinked foam sheet production using EVA 1519 generally employs a counter-rotating conical twin-screw extruder with screw diameter of 92 mm and L/D ratio of 36:1, operated at a melt temperature of 115°C to 125°C to delay peroxide decomposition during mixing. Azodicarbonamide blowing agent loadings from 6 phr to 12 phr and dicumyl peroxide loadings from 0.8 phr to 1.4 phr generate foam densities of 0.08 g/cm³ to 0.20 g/cm³ in sheet form. The 1.9 g/10 min melt flow rate of EVA 1519 improves bubble retention during expansion relative to grades with melt flow rates above 3.0 g/10 min, because the higher melt strength reduces cell coalescence under biaxial stretch at the calender. Final foam mechanical properties are evaluated by ISO 1798:2008 for tensile strength and elongation, and compression set after 50% deflection is measured by ISO 1856:2018. Published grade-specific data for all formulation variants is limited; converter trials are required to fix exact density and hardness.

When EVA 1519 Replaces Low-Density Polyethylene in Extrusion Lamination

Extrusion lamination of aluminium foil, paper, and oriented polyester film with EVA 1519 uses the vinyl acetate functionality to promote wet-out and adhesion on polar metallic surfaces, but the low melt flow rate requires a shorter air gap and higher backpressure than low-density polyethylene. On a 90 mm single-screw laminator with L/D ratio of 30:1, melt temperatures at the die exit from 215°C to 225°C and an air gap of 100 mm to 150 mm provide consistent coating weight without excessive neck-in. Peel adhesion of a 20 µm EVA layer on aluminium foil is measured by ASTM F904-16; reported values in industrial lamination typically exceed 2.0 N/15 mm when substrate preheating above 30°C is applied. Compared with EVA grades containing 18 wt% vinyl acetate, EVA 1519 exhibits higher tensile modulus and better heat resistance but lower adhesion to high-polarity substrates and reduced low-temperature flexibility. Published data for this specific grade in thin-film extrusion lamination remains limited, so pilot-line verification under ISO 11339:2022 is necessary before full commercial qualification.

On injection molding lines with clamp force from 1,200 kN to 2,000 kN, EVA 1519 is processed with barrel temperatures from 150°C to 190°C, mold temperatures from 20°C to 40°C, and injection pressures from 60 MPa to 120 MPa. Mold shrinkage after 24 h at 23°C is typically 1.5% to 2.0% in the flow direction when measured according to ISO 294-4:2018. Ejection from polished steel cavities requires mold release systems free of amine-based active ingredients; unmodified EVA may adhere to metal surfaces and generate sticking during high-speed cycles. Cyclic compression fatigue is evaluated on a servohydraulic tester at 5 Hz to 10 Hz; published data for this exact grade under footwear-type flexing is limited. The material is not recommended for contact with aromatic or chlorinated solvents, which induce swelling and extraction of low-molecular-weight fractions.

Representative values in the comparison table are drawn from publicly available technical literature for ethylene-vinyl acetate copolymers with equivalent nominal composition and are not release limits for any single production lot. The principal differentiation of EVA 1519 is the combination of 15 wt% vinyl acetate and 1.9 g/10 min melt flow rate, which provides a processing window between low-flow film grades and high-flow injection grades.

Regulatory Status and Pre-Drying Requirements for Food-Contact and Extrusion Operations

Under EU Regulation No 10/2011, EVA 1519 may be used in food-contact layers if the finished article meets overall migration limits evaluated by EN 1186-1:2002; the converter must account for the vinyl acetate monomer specific migration limit and any adhesive or slip additives. FDA status for ethylene-vinyl acetate copolymers is defined in 21 CFR 177.1350, but compliance is not intrinsic to the polymer and requires verification of the full formulation. RoHS Directive 2011/65/EU heavy metal thresholds are assessed by IEC 62321-5:2013 for cadmium and IEC 62321-4:2013 for lead; raw-material certificates should be retained. REACH Regulation (EC) No 1907/2006 requires confirmation that no substances of very high concern exceed 0.1 wt% in the supplied pellet, based on the Candidate List current at the time of import.

Moisture uptake above 0.05 wt% by Karl Fischer titration can cause surface defects and microvoids in extruded profiles and sheet. Pre-drying in a desiccant dryer at 60°C to 70°C for 4 h to 6 h is required when storage relative humidity exceeds 60% or when pellets have been exposed to ambient air for more than 72 h. Drying temperature above 80°C is not recommended because pellet agglomeration can occur before the moisture is removed.

Profile extrusion of EVA 1519 on a 60 mm single-screw extruder with breaker plate and screen pack, operating at melt temperatures from 160°C to 190°C, produces gaskets, tubing, and edge-protection profiles. The low melt flow rate of 1.9 g/10 min supports dimensional stability after die swell, but line speed must be reduced relative to higher-MI grades to compensate for higher head pressure and shear heating. Draw-down characteristics are evaluated by measuring profile cross-sectional area against haul-off speed; a draw ratio of 1.1:1 to 1.5:1 is typical for this grade. Because EVA 1519 has a Vicat softening temperature of approximately 74°C when tested to ISO 306:2022, continuous service at temperatures above 60°C under load can cause dimensional recovery issues.