| HS Code | 323065 |
| Vinyl Acetate Content Wt | 40 |
| Melt Flow Index G 10 Min At 190 C 2 16 Kg | 3.1 |
| Density G Cm³ | 0.965 |
| Melting Point Dsc C | 65 |
| Glass Transition Temperature C | -35 |
| Tensile Strength At Break Mpa | 5.8 |
| Elongation At Break | 900 |
| Shore A Hardness | 55 |
| Flexural Modulus Mpa | 18.6 |
| Vicat Softening Temperature C | 32 |
| Brittleness Temperature C | -100 |
As an accredited ELVAX 4031WLG Ethylene Vinyl Acetate Copolymer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | ELVAX 4031WLG ethylene vinyl acetate copolymer supplied as free-flowing pellets, packaged in 25 kg bags. |
| Container Loading (20′ FCL) | 20′ FCL container loaded with ELVAX 4031WLG ethylene vinyl acetate copolymer resin, securely packed in bags for transport. |
| Shipping | ELVAX 4031WLG is shipped as solid pellets in sealed, moisture-protective bags or drums. Transport away from heat, open flames, and incompatible oxidizers. Keep dry and ventilated. No dangerous goods classification under standard conditions, but avoid dust accumulation. Handle with PPE and follow standard industrial hygiene practices. |
| Storage | Store ELVAX 4031WLG in its original, unopened container in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and open flames. Keep containers tightly sealed to prevent moisture pickup and contamination. Avoid contact with strong oxidizers. Maintain storage temperatures below 30°C (86°F). Follow all label and safety data sheet instructions. |
| Shelf Life | Shelf life is typically two years from shipment when stored in original packaging, away from heat, moisture, and sunlight. |
Photovoltaic encapsulant film lines running ELVAX 4031WLG typically compound the resin by tumble-blending 100 phr pellets with 1.0–1.5 phr tert-butyl peroxy-2-ethylhexyl carbonate, 0.3–0.5 phr vinyltrimethoxysilane, 0.2–0.5 phr of a phosphite-phenol antioxidant blend, and, where a white reflective encapsulant is required, 5–10 phr of a titanium dioxide masterbatch. The grade carries a nominal vinyl acetate content of 40 wt% and a melt flow rate of 3.1 g/10 min under ISO 1133-1:2022 at 190°C and 2.16 kg, placing it in a low-flow, high-polarity class that requires melt-confining screw geometry rather than high-shear homopolymer-grade screws. In a single-screw extruder with 30:1 L/D, barrel temperatures are set from 85°C at the feed throat to 105°C at the metering section, while the flex-lip die and melt pump are maintained at 110–115°C to suppress premature peroxide decomposition. The film is cast onto a polished chill roll at 20–30°C, and gauge is controlled to 400–500 µm before lamination. Hot spots near the die lips generate gel specks that appear as colourless inclusions in the cured module; the defect rate increases when melt residence exceeds 20 min or when the product contains moisture above 0.05 wt%. Pre-drying in a desiccant hopper at 60°C for 4 h is therefore standard in plant environments above 60% RH. Crosslinking occurs during vacuum lamination at 145–150°C for 15–20 min; gel content measured by solvent extraction in boiling xylene under ASTM D2765-16 is targeted at 70–85 wt%. Published data for ELVAX 4031WLG in high-speed photovoltaic encapsulant lines is limited, so the specified peroxide ratio and gel-content window are to be confirmed against lot-specific rheology data before die-lip modifications are approved.
In three-layer blown film structures for laminated pouches and frozen-food bags, ELVAX 4031WLG is let down into the sealant skin at 20–40 wt% with a linear low-density polyethylene carrier. The addition range is limited at the upper end because the high vinyl acetate content raises melt stickiness and the wound roll blocking force increases sharply above 40 wt% EVA when the film is stored above 35°C ambient temperature. The sealant skin is coextruded on a spiral mandrel die with a die gap of 1.5–2.0 mm and a blow-up ratio of 2.2:1 to 2.8:1; melt temperatures are kept between 195°C and 215°C, and purge time at idle is capped at 15 min because stagnant melt releases acetic acid and accelerates die-lip corrosion. Hot-tack force is measured on a laboratory seal tester according to ASTM F1921-18, and seal strength after cooling is measured under ASTM F88/F88M-21. For a 30 wt% EVA sealant web, converters typically require a seal initiation temperature below 85°C at 0.3 MPa seal pressure and 0.5 s dwell, with a seal strength above 2.0 N/15 mm; published data for this exact ELVAX 4031WLG dilution is limited, and the threshold shifts downward with increasing corona treatment level. The final sealant layer must satisfy the overall migration and polymer-specific conditions shown in the compliance table below.
| Regulation/Standard | Provision | EVA-Specific Requirement | Verification Point |
|---|---|---|---|
| FDA 21 CFR 177.1350 | Ethylene-vinyl acetate copolymers in food-contact articles | Vinyl acetate content within the limits stated in the regulation; no use above prescribed temperature limits | Batch certificate of composition and extraction testing |
| EU Regulation 10/2011 Annex I | Plastic materials and articles intended to contact food | Overall migration limit of 10 mg/dm²; specific migration limit for vinyl acetate of 12 mg/kg food simulant | Migration testing under intended food-simulant and time-temperature conditions |
| REACH Regulation (EC) No 1907/2006 | Registration, evaluation, authorisation and restriction of chemicals | No substance of very high concern above 0.1 wt% in the finished article | Supplier declaration and periodic SVHC screening |
| RoHS Directive 2011/65/EU Annex II | Restriction of hazardous substances in electrical and electronic equipment | Lead, mercury, cadmium, hexavalent chromium, PBB and PBDE below directive thresholds | XRF screening and wet chemical confirmation |
In halogen-free sheathing compounds for control and power cables, ELVAX 4031WLG is used as the polymeric wetting phase because the acetate side groups interact with uncoated alumina trihydrate surfaces and permit filler loadings that would otherwise cause brittle failure in low-polarity polyolefins. The manufacturing procedure begins with a co-rotating twin-screw extruder of 44:1 to 52:1 L/D; resin is fed by loss-in-weight at the main throat, while dried alumina trihydrate is side-fed downstream at total loadings between 150 phr and 180 phr per 100 phr resin. Magnesium dihydrate is added at 10–20 phr only when the final cable specification requires a char plateau above 300°C; higher additions reduce tensile elongation below the 150% threshold required by many IEC 60811-series tests. The screw configuration uses distributive mixing elements after the side feeder and a low-pressure die zone, with barrel temperatures from 120°C at intake to 160°C at discharge. Operation above 170°C is avoided because the alumina trihydrate decomposition endotherm becomes measurable and moisture-driven porosity appears in the pellet. The compound is pelleted under water and dried to less than 0.1 wt% moisture before silane grafting or peroxide addition in the cable extrusion stage. Finished sheathing is tested for acid gas generation per IEC 60754-1:2011 and IEC 60754-2:2011, smoke density per IEC 61034-2:2005, and flame spread per IEC 60332-1-2:2015.
| Process variable | Control band | Monitoring method | Deviation signature |
|---|---|---|---|
| Main feeder zone temperature | 120–130°C | Calibrated thermocouple, weekly verification | Screw overload from unmelted EVA granules |
| Side feeder filler temperature | <150°C | Infrared spot pyrometer | Surface moisture flash and pellet porosity |
| Melt temperature at die head | 155–165°C | Immersion probe during strand start-up | Acidic odour and brown speck formation |
| Pellet moisture after centrifuge | <0.1 wt% | Karl Fischer titration | Void formation during cable extrusion |
Compression-moulded EVA foams for footwear midsoles use ELVAX 4031WLG at 100 phr with azodicarbonamide at 3.0–5.0 phr, dicumyl peroxide at 0.6–0.9 phr, zinc oxide at 2.5–5.0 phr, stearic acid at 1.0–2.0 phr, and calcium carbonate at 10–20 phr. The resin’s low melt flow rate of 3.1 g/10 min at 190°C under ISO 1133-1:2022 functions as a melt-strength reserve; cell coalescence is less frequent than with high-MI EVA when the gas pressure inside the growing cells exceeds the elongational strength of the melt during mould opening. Mixing is carried out on an open two-roll mill with a front roll temperature of 85–95°C and a friction ratio of 1.15:1. The compounded sheet is cut into preforms and placed into a compression mould at 165–175°C and 150–200 kg/cm² for 8–12 min. The blowing and crosslinking reactions must reach their exothermic peaks nearly simultaneously; a premature peroxide peak causes a dense skin and an underblown core, while a late peroxide peak allows cell collapse and surface cratering. Moving-die rheometry at 170°C is used to confirm a t90 below 8 min. Foam density is verified per ISO 845:2006, compression set per ISO 815-1:2014, and Asker C hardness per JIS K 7312. Typical density after free expansion is in the range 0.12–0.20 g/cm³, with skin density measurably higher than core density; published data for ELVAX 4031WLG in this specific foam formulation is limited, so the blowing-agent and peroxide split should be confirmed on a small-scale press before production.
Solventborne adhesive formulations for film-to-foil lamination dissolve ELVAX 4031WLG in a 70/30 wt% toluene/methyl ethyl ketone blend at 12–18 wt% solids. The dissolution is conducted in a jacketed mixer at 55–60°C for 2–4 h; the low melt index grade requires longer solvation than high-MI EVA, but the resulting solution exhibits higher green strength and creep resistance. After cooling, a hydrogenated rosin ester tackifier is added at 5–10 parts per 100 parts dry resin, and the viscosity is adjusted to 400–800 mPa·s at 25°C using a Brookfield RVT viscometer. The coat weight is controlled at 3–6 g/m² dry on a reverse-roll coater, followed by forced-air drying at 80–90°C. Bond strength is evaluated by T-peel under ASTM D1876-08; foil-to-polypropylene laminations commonly require at least 2.5 N/15 mm. Operational boundaries include solvent flammability under Directive 2010/75/EU and the sensitivity of vinyl acetate to alkaline hydrolysis; amine-cured primers or amine-containing inks can shift the wet adhesive pH and produce viscosity growth during long production runs. Published data for ELVAX 4031WLG in this exact solventborne system is limited, so the viscosity-solids relationship should be measured for every lot before solvent addition is reduced on the coating line.
Bituminous roofing membranes and damping sheets are modified with ELVAX 4031WLG at 6–12 wt% of the total bitumen mass. The EVA pellets are added to oxidized bitumen at 170–180°C in a high-shear rotor-stator mixer; batch residence time is held at 60–90 min because the crystalline ethylene segments need time to melt and disperse into a continuous bitumen-rich phase. Above 12 wt% addition, the compound frequently enters a phase inversion and the viscosity at application temperature rises beyond the pumping range of standard spreader machines, producing uneven heat-welded seams. Softening point is checked under ASTM D36-14, penetration under ASTM D5-20, and low-temperature flexibility under EN 1109:2013. Storage stability is assessed according to EN 13399:2017 at 180°C for 3 days; visible phase separation or a penetration split greater than 10 dmm between top and bottom layers indicates insufficient shear dispersion. Since the grade contains 40 wt% vinyl acetate, prolonged storage above 200°C accelerates acetic acid release and can attack unlined carbon steel tanks; stainless steel or phenolic-lined vessels are specified for closed-loop blending systems.
Injection moulded cable entry seals, pipe gaskets, and vibration-isolation parts are produced from ELVAX 4031WLG blended with 15–25 wt% of an ethylene-propylene rubber or styrenic block copolymer and 5–10 wt% mineral filler. The blend is moulded on a reciprocating-screw injection machine with a clamp force of 120–180 t, a screw L/D of 22:1, and a compression ratio of 2.0:1. Barrel temperatures from feed to nozzle are set at 140°C, 165°C, 175°C, and 185°C, with the hot runner held at 185–190°C. The low melt flow rate of 3.1 g/10 min under ISO 1133-1:2022 imposes a minimum gate diameter of 1.2 mm; smaller gates produce jetting, weld-line weakness, and surface delamination because the long relaxation time of the high-molecular-weight EVA phase prevents molecular re-entanglement before quench. Mould temperatures are controlled between 20°C and 40°C; higher mould temperatures reduce orientation but extend cycle time beyond 60 s. The demoulded article is tested for Shore A hardness under ISO 48-4:2018, tensile strength under ISO 527-2:2012, and compression set under ISO 815-1:2014. A common failure mode on production lines is gas-burning streaks when the screw back pressure is set below 5 bar, resulting in inadequate homogenization of the EVA and rubber phases.
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ELVAX 4031WLG ethylene vinyl acetate copolymer is a high-polarity EVA resin in which the vinyl acetate comonomer content is expected from the grade designation to reside in the 40 wt% class; exact melt mass-flow rate, vinyl acetate concentration, and stabiliser package require confirmation against the supplier technical data sheet before compounding. The vinyl acetate repeat unit interrupts polyethylene crystallinity, producing a resin with lower crystalline melting point, higher clarity, improved filler wetting, and greater adhesion to polar substrates than unmodified low-density polyethylene. Melt mass-flow rate is normally characterised under ISO 1133-1:2022 or ASTM D1238-23c at 190°C/2.16 kg; tensile properties are tracked by ISO 527-2 or ASTM D638-14; hardness can be reported as Shore D or Shore A under ASTM D2240-15e1. The material is positioned for flexible packaging sealants, hot-melt adhesives, polymer modification, and low-gel wire and cable compounds. Because published data for this specific configuration is limited, property parity with other 40 wt% VA grades should not be assumed.
Increasing vinyl acetate content from the 18 wt% class to the 40 wt% class reduces crystalline fraction and shifts thermal transitions toward lower temperatures. Differential scanning calorimetry under ISO 11357-3:2018 on high-VA EVA typically shows a broad melting endotherm between 40°C and 60°C, with a glass transition near -25°C; exact onset and enthalpy depend on thermal history and comonomer sequence distribution. The lower crystallinity reduces heat-seal initiation temperature on production laminators and permits flow into paperboard, polyester, and aluminium foil surfaces at lower jaw temperatures. Heat-seal strength is measured after seal preparation under ASTM F2029-16, and hot-tack behaviour is measured under ASTM F1921-18 Method A.
In peel testing under ASTM D1876, high-VA EVA adhesives commonly transition from interfacial adhesive failure to cohesive failure as seal temperature increases. The optimum seal window is defined not only by maximum peel force but also by fibre tear or cohesive failure on the weaker substrate. On production-scale flat-die coextrusion lines, chill-roll temperatures between 15°C and 25°C are used to prevent blocking; the low crystalline melting point of the 40 wt% VA class narrows the blocking margin compared with 18 wt% VA grades. The exact seal-initiation temperature for ELVAX 4031WLG is not supplied in this document but is expected to be lower than that of EVA grades in the 25–28 wt% VA class.
In hot-melt adhesive manufacturing, the high vinyl acetate content increases compatibility with rosin ester and aromatically modified tackifier systems; ring-and-ball softening point is determined under ASTM E28 and molten viscosity at 180°C under ASTM D3236-15. Formulators typically use resin-to-EVA ratios between 1:1 and 3:1 by weight, with wax addition controlled to adjust open time and set speed. Production-scale sigma-blade mixers or continuous twin-screw kneaders operate at melt temperatures from 130°C to 150°C; the wax should be staged after tackifier and EVA have formed a homogeneous melt to avoid viscosity stratification. Adhesive performance is tracked by ASTM D1876 T-peel on aluminium or polyester film and by ASTM D4498 shear adhesion failure temperature. Boundary conditions apply: the material alone is not suitable for sustained load-bearing above 60°C unless crosslinked or modified with a higher-softening-point tackifier.
For unfilled blending with compatible ethylene copolymers, dry blending in a low-intensity ribbon blender followed by single-screw melt compounding is sufficient; no further elaboration is warranted.
Resin moisture should be reduced to 0.05 wt% or less before compounding; drying at 60°C for 4 h in a desiccant-bed dryer is typical for high-VA EVA pellets. Drying temperatures above 70°C may cause pellet clumping because of surface tack. A co-rotating twin-screw extruder with 40:1 L/D is commonly used; side-stuffer addition after polymer melting reduces wear and disperses aluminium trihydrate or magnesium hydroxide without excessive shear heating. Melt temperature should be capped below 170°C, and the vent port should be maintained under vacuum to remove moisture and low-level acetic acid formed by thermal hydrolysis of vinyl acetate.
Aluminium trihydrate releases water beginning at approximately 180°C, while magnesium hydroxide decomposes near 340°C; processing of ATH-filled compounds therefore requires strict melt-temperature control to avoid intumescent decomposition within the extruder. Moisture and vinyl acetate hydrolysis can liberate acetic acid, which corrodes unplated surfaces; chrome-plated or nitrided barrel segments are preferred over exposed low-alloy steels. Amine-based heat stabiliser packages are not recommended in high-VA EVA compounds because liberated acetic acid can form acetate salts that plate out on die lips. Calcium stearate or zinc oxide may be used at 0.05–0.15 phr as acid scavengers, but dispersion and effect on electrical properties must be confirmed in the final formulation.
Line monitoring should include melt pressure, melt temperature, torque, specific mechanical energy, and residence-time distribution. Volatile acetic acid emission can be assessed by thermogravimetric analysis with infrared detection under ISO 11358-1:2022 or by headspace gas chromatography–mass spectrometry. Bulk density of pellets and filler incorporation uniformity can be checked under ASTM D1895-17. Production-scale loss-in-weight feeders should maintain additive rate accuracy within ±0.5% of setpoint to avoid batch-to-batch variance in flame-retardant performance.
Where the WLG suffix denotes a low-gel wire and cable grade, the resin is intended to reduce die-lip buildup and surface pitting that can occur in thin-wall insulation and jacketing. Gel content for peroxide-cured EVA insulation is commonly measured by ASTM D2765-16 using decalin or xylene extraction; a fully cured insulation may reach 70–90% gel depending on formulation and cure state. For silane-grafted moisture-cured compound, gel formation is tested after immersion in a 60°C water bath for 8–24 h; published data for ELVAX 4031WLG in this specific configuration is limited.
Halogen-free flame-retardant EVA insulation often uses aluminium trihydrate or magnesium hydroxide loadings from 120 phr to 180 phr depending on the cable performance class. Oxygen index is measured under ASTM D2863; typical halogen-free EVA compounds are formulated above 28% oxygen index to support vertical flame tests such as IEC 60332-1-2. The high vinyl acetate content permits high filler uptake while retaining elongation at break above 150% when measured under ASTM D638-14; the exact value depends on filler type, surface treatment, and coupling agent. Continuous vulcanisation lines used for peroxide-cured EVA insulation should keep die melt temperature below 120°C to prevent scorch, while the cure tube operates at 180–200°C under steam or nitrogen pressure. Low-gel character is particularly important where melt filtration and screen-pack pressure rise are used as incoming resin quality indicators; a gel-count threshold should be agreed with the supplier rather than inferred from standard melt flow rate alone.
Regulatory compliance for ELVAX 4031WLG should not be assumed from generic EVA statements. The following matrix defines the categories most often required in technical dossiers.
| Standard or regulation | Relevance | Verification condition |
|---|---|---|
| REACH Regulation (EC) No 1907/2006 | Registration status and Substances of Very High Concern content | Supplier confirmation required for grade-specific polymer and additives |
| RoHS Directive 2011/65/EU | Lead, cadmium, mercury, hexavalent chromium, PBB, PBDE restrictions | Applies to finished electrical and electronic assemblies rather than raw polymer |
| FDA 21 CFR 177.1350 | Ethylene-vinyl acetate copolymers for food-contact use | Compliance depends on comonomer content and extractives; confirm section conditions |
| EU Regulation 10/2011 | Plastic materials intended for food contact | Migration testing must be performed on the final article |
| ISO 1133-1:2022 | Melt mass-flow rate | Reported at 190°C/2.16 kg; method and drying state must be stated |
| ASTM D2765-16 | Gel content by solvent extraction | Used for crosslinked or low-gel wire compound quality control |
The regulatory matrix above covers common polymer compliance categories but does not replace supplier documentation for food-contact, medical, or electrical end-use. Electrical volume resistivity is measured under ASTM D257; any surface treatment, filler, or acid scavenger can alter the final insulation resistance and must be validated on the completed cable construction.
Thermal degradation of high-vinyl-acetate EVA proceeds through deacetylation and main-chain scission, releasing acetic acid and shifting melt viscosity and colour. Pyrolysis literature commonly reports effective activation energies in the range 180–220 kJ/mol for inert-atmosphere EVA decomposition; the exact value depends on vinyl acetate content, heating rate, and formulation. The degradation reaction becomes practically significant above 170°C when residence time is extended, and auto-accelerates because acetic acid promotes further ester cleavage. The material should therefore be processed with barrel and die temperatures below 170°C, total residence time below 10 min, and open-vent vacuum where volatile removal is required.
Above 230°C, discoloration accelerates and melt viscosity drops sharply; reprocessing of heavily degraded material is not recommended because the acid by-products can corrode downstream metal surfaces. Bronze, brass, and unplated copper fittings should be avoided in melt-transfer lines; stainless steel with vapour-phase corrosion inhibitor may be used where acetic acid exposure is expected. Thermogravimetric analysis under ISO 11358-1:2022 coupled with Fourier-transform infrared detection can distinguish acetic acid evolution from filler decomposition. Melt filtration tests during extrusion can detect gel formation or char, and melt flow rate after compounding should be compared with incoming resin values under ISO 1133-1:2022 to quantify molar mass changes. The selection of antioxidants and acid scavengers must be made in the final compound rather than inferred from lower-VA EVA grades, because the vinyl acetate-rich phase responds differently to hindered phenolic and phosphite stabiliser packages.
Compared with ethylene methyl acrylate copolymers and metallocene plastomers of equivalent melt flow rate, the 40 wt% vinyl acetate class generally offers greater surface polarity and filler wetting but lower thermal stability and a higher coefficient of friction; final selection is resolved by comparative testing under ISO 527-2 and ASTM D257 where electrical properties apply. Lower-VA EVA grades in the 18–28 wt% range retain more crystalline strength and are preferred for higher-stiffness films and overmoulding, while EMA may offer superior thermal stability at equivalent polarity. The exact position of ELVAX 4031WLG relative to these alternatives should be established on production-scale equipment, because published data for this specific configuration is limited.
