| HS Code | 934974 |
| Vinyl Acetate Content | 40 wt% |
| Melt Flow Rate | 52 g/10 min (190°C, 2.16 kg) |
| Density | 0.970 g/cm3 |
| Tensile Strength At Break | 7.6 MPa |
| Elongation At Break | 680% |
| Shore A Hardness | 80 |
| Melting Point | 62°C |
| Vicat Softening Point | 36°C |
| Brittleness Temperature | -70°C |
| Refractive Index | 1.470 |
| Volume Resistivity | 10^15 ohm-cm |
As an accredited Elvax 40W EVA Copolymer Resin,40% VA,High Elastomer Adhesive Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Elvax 40W EVA resin supplied as translucent pellets in 25 kg polyethylene-lined paper bags, ensuring moisture protection and handling convenience. |
| Container Loading (20′ FCL) | 20' FCL: Elvax 40W resin packed in 25kg bags on pallets, shrink-wrapped and container-loaded for safe transport. |
| Shipping | Elvax 40W EVA resin ships as solid pellets in moisture-proof bags or drums. Keep dry, away from direct heat and ignition sources. Non-hazardous under normal transport, but avoid excessive temperatures to prevent agglomeration. Use clean, covered containers to preserve quality during handling and transit. |
| Storage | Store Elvax 40W EVA resin in a cool, dry, well-ventilated area, away from direct sunlight, heat sources, and open flames. Keep the original container tightly sealed to prevent moisture absorption and contamination. Avoid contact with strong oxidizers. Ideal storage temperature is below 30°C (86°F). Proper storage ensures product stability and performance. |
| Shelf Life | Shelf life is typically two years from manufacture when stored in cool, dry conditions away from direct sunlight. |
In hot-melt packaging and product assembly operations, the molten adhesive is compounded in electrically heated Sigma-blade mixers or heated planetary mixers at jacket temperatures between 160 °C and 180 °C, then transferred through gear pumps or extruder melt pumps to slot-die or roller coaters. With Elvax 40W, the 40 wt% vinyl acetate content lowers crystalline melting enthalpy and raises room-temperature tack on polar substrates such as corona-treated polyethylene terephthalate, aluminium, and clay-coated paperboard. The melt flow index measured under ASTM D1238 at 190 °C with a 2.16 kg load is 52 g/10 min, which places the material in a low-viscosity hot-melt carrier class requiring careful control of wax type and loading to avoid phase separation. In continuous production lines, the processing window is bounded by two failure modes: at temperatures below 150 °C full homogenization with high-melting Fischer-Tropsch wax is incomplete, while at temperatures above 200 °C measurable acetic acid elimination begins and corrodes carbon steel melt tanks. Batch records from adhesive manufacturing lines show that a melt temperature excursion to 220 °C for 15 minutes produces visible gel particles and a darkening of 2 to 3 Gardner units, with an accompanying peel adhesion reduction that varies with substrate and coating weight. For this reason, oil-jacketed heating systems with ±2 °C control are specified rather than direct electric band heaters.
Formulation design with 35 wt% to 40 wt% Elvax 40W in a rosin ester tackifier system yields a Brookfield viscosity at 180 °C in the 700 mPa·s to 1,400 mPa·s range when the tackifier softening point is between 95 °C and 105 °C. Increasing the wax fraction above 25 wt% lowers viscosity but reduces T-peel adhesion on coated board below 2 N/mm when tested according to ASTM D1876. A representative packaging formulation uses 38 wt% Elvax 40W, 42 wt% pentaerythritol rosin ester, 19 wt% Fischer-Tropsch wax with a congealing point of 100 °C, and 0.5 phr of a hindered phenolic antioxidant. The antioxidant is added before the polymer reaches 140 °C to interrupt radical chain degradation during the 45 to 60 minute mixing cycle. Batch-to-batch variation in the wax congealing point above ±3 °C shifts the high-shear viscosity by more than 10 percent and requires a temperature adjustment of 5 °C to maintain constant coating weight.
| Parameter | Standard or regulation | Condition or limit |
|---|---|---|
| Melt flow index | ASTM D1238, ISO 1133-1:2022 | 52 g/10 min at 190 °C, 2.16 kg |
| Hot-melt viscosity | ASTM D3236 | Brookfield, 180 °C, 0.7–1.4 Pa·s depending on formulation |
| Food contact adhesive | FDA 21 CFR 175.105 | Adhesive components in food packaging |
| Ethylene-vinyl acetate copolymer | FDA 21 CFR 177.1350 | Conditions for EVA copolymers in food contact |
| Restricted substances screening | IEC 62321 | Pb, Cd, Hg, Cr(VI), PBB, PBDE |
| Peel adhesion | ASTM D1876 | T-peel on coated board |
| Softening point | ASTM E28 | Ring-and-ball for wax and tackifier blends |
The substitution of a 40 wt% vinyl acetate grade for an 18 wt% or 28 wt% VA copolymer alters both the solubility parameter and the crystalline melting profile of the wax blend. In hot melt and solvent wax coating formulations used for corrugated board, candle over-dipping, and fruit coating, the higher acetate content increases polarity and reduces crystallinity, allowing the polymer to absorb more paraffin oil without syneresis. Published formulation studies show that a 5 wt% addition of Elvax 40W to a 70:30 paraffin/microcrystalline wax blend raises the kinematic viscosity at 100 °C by 30 to 60 percent and increases coating flexibility at −10 °C. The processing change is non-linear: at addition levels above 8 wt%, the melt becomes hazy and the ring-and-ball softening point drops below 85 °C when measured under ASTM E28. In continuous wax coating lines, the EVA must be pre-dispersed in a high-shear homogenizer at 150 °C before final letdown in the holding tank because direct pellet addition to wax at 120 °C leaves gel specks. These gel specks are observed as coating defects and are caused by the melting point depression of the paraffin phase rather than by polymer degradation. A production-scale batch using a high-shear dispenser with a tip speed of 18 m/s at 150 °C reaches adequate dispersion after 30 minutes, whereas a low-speed propeller mixer requires 90 minutes and leaves visible undispersed polymer at the same temperature. For food contact wax coatings, the formulation must still comply with FDA 21 CFR 176.170 and FDA 21 CFR 175.105, with the EVA component covered by FDA 21 CFR 177.1350 when the vinyl acetate content does not exceed the clause limit.
In rigid and semi-rigid PVC extrusion, high-vinyl acetate EVA functions as a non-migrating polymeric plasticizer and impact modifier when compounded on twin-screw extruders with L/D ratios between 36:1 and 44:1. The vinyl acetate segments in Elvax 40W provide polar interaction with the PVC chain, but the polyolefin backbone limits solubility; therefore the addition window is narrow. At 5 phr to 10 phr in a PVC pipe or window profile formulation, notched Izod impact strength measured under ISO 180 increases, but at loadings above 12 phr the tensile modulus falls by more than 25 percent and the Vicat softening temperature of the compound can drop below 70 °C. Because PVC degrades in the same thermal region where EVA 40W begins deacetylation, the processing window is constrained to 170 °C to 185 °C in the metering zone, and the vent port must be run at −0.08 MPa to withdraw acetic acid traces. Field trials have shown that pellet pre-blending with PVC dry blend in a hot mixer at 90 °C for 10 minutes is required to prevent screw slippage in the feed zone when the EVA level exceeds 8 phr. The modification mechanism is a dispersed elastomer phase rather than full molecular miscibility; domain size depends on applied shear and melt temperature, and coarse domains above 2 µm reduce impact transfer efficiency.
Where solvent-borne contact adhesives require room-temperature solubility without pre-dissolution heating, Elvax 40W is dissolved in toluene, methyl ethyl ketone, or cyclohexane-ester blends at solids contents of 15 wt% to 25 wt%. The high vinyl acetate content imparts solubility in ketonic and ester solvents that is absent in lower-VA grades. A 20 wt% solution in a 70:30 toluene/methyl ethyl ketone mixture at 25 °C has a Brookfield viscosity of 800 mPa·s to 1,500 mPa·s depending on molecular weight distribution and storage time; the solution must be held in closed mixing vessels because methyl ethyl ketone vapour forms explosive mixtures at 1.8 vol% to 11.5 vol% in air. In coating lines, the drying tunnel temperature is limited to 55 °C to 65 °C for the first zone to avoid skinning and solvent blistering, then raised to 80 °C in the final zone to reduce residual solvent below 0.5 mg/m². When applied as a contact adhesive for footwear or furniture lamination, the open time is set by solvent evaporation rate; addition of 5 wt% rosin ester tackifier extends open time but reduces final cohesive strength after 7 days. Because solvent-borne systems have moved to low-VOC alternatives, this application is confined to industrial lamination where waterborne or hot-melt systems fail on non-porous rubber or polyurethane foam.
Removable and semi-permanent label adhesive development using Elvax 40W encounters a cohesion/adhesion conflict that is controlled by the ratio of liquid C5 hydrocarbon resin to high-softening-point rosin ester. In a hot-melt pressure-sensitive system, Elvax 40W is compounded at 30 wt% to 35 wt% with a liquid C5 hydrocarbon resin and a solid rosin ester to produce a loop tack value of 3 N to 6 N on stainless steel when tested according to PSTC-16. The 180° peel adhesion on stainless steel at 25 °C falls between 2 N/25 mm and 4 N/25 mm after 24 hours, but the holding power at 40 °C under a 1 kg load drops below 6 hours when the C5 resin loading exceeds 35 wt%. To maintain cohesion, a high-softening-point rosin ester with a ring-and-ball softening point of 110 °C or greater is used at 20 wt% to 25 wt%; lower softening points cause edge oozing in roll form. Formulators must avoid amine-based stabilizers because the acetate group can undergo transamidation at elevated temperature, generating amide by-products and reducing cohesive strength. On a production coater, the adhesive is applied at 165 °C through a slot die with a coat weight of 20 g/m² to 25 g/m² onto silicone release liner, then laminated to 80 g/m² paper face stock.
The low crystallinity and high polarity of a 40 wt% vinyl acetate copolymer allow high loadings of aluminium trihydrate and magnesium dihydroxide in halogen-free flame retardant cable jacket compounds without the environmental stress cracking observed with low-density polyethylene. Elvax 40W is compounded with 60 wt% to 65 wt% precipitated magnesium dihydroxide on a co-rotating twin-screw extruder with an L/D ratio of 44:1 and a screw speed of 300 rpm; the specific mechanical energy input is controlled between 0.15 kWh/kg and 0.20 kWh/kg. The 40% VA segments provide free volume and polar adhesion to the filler surface, enabling a tensile elongation at break above 150 percent under IEC 60811-501 even at 65 wt% filler loading. Flame retardant performance is verified by a limiting oxygen index above 32 percent under ISO 4589-2 and by pH and conductivity measurements under IEC 60754-2. The main processing conflict is the temperature ceiling: the compound must not exceed 190 °C in the final 2D of the screw or deacetylation reduces insulation resistance after water immersion. Pre-drying of the filler to below 0.1 wt% moisture is mandatory when relative humidity exceeds 60 percent in the compounding hall, otherwise foaming occurs at the die.
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Elvax 40W EVA Copolymer Resin, 40% VA, High Elastomer Adhesive Grade is an ethylene-vinyl acetate copolymer supplied in pellet form. The resin carries a nominal vinyl acetate comonomer content of 40 wt% and a typical melt flow rate of 52 g/10 min at 190 °C under a 2.16 kg load when tested in accordance with ASTM D1238. Its density is 0.965 g/cm³ at 23 °C per ASTM D1505. The high vinyl acetate level interrupts polyethylene crystallinity, producing a low-modulus, highly extensible resin that functions primarily as a cohesive modifier in hot-melt adhesives, sealants, and wax blends. The resin is not a standalone adhesive; it is compounded with tackifiers, waxes, oils, and antioxidants to balance open time, heat resistance, and substrate wetting.
The grade is differentiated from lower-vinyl-acetate EVA products by its combined comonomer level and melt flow rate. Many EVA grades with vinyl acetate contents below 28 wt% retain measurable polyethylene crystallinity, higher tensile modulus, and lower polarity. Elvax 40W sits in the high-VA portion of the portfolio, where the resin behaves as a flexible modifier rather than a rigid thermoplastic. This property set is relevant to hot-melt packaging, bookbinding, pressure-sensitive assembly, and wax-coating operations where low application viscosity and adhesion to polar surfaces are required. In comparison with lower-vinyl-acetate EVA grades, the 40% VA structure provides greater polarity, improved adhesion to metals and polar plastics, and increased compatibility with rosin ester and terpene-phenolic tackifiers. The high melt flow rate reduces energy input during compounding and improves penetration into porous surfaces, while limiting cohesive strength after application when compared with lower-melt-index EVA grades.
The melt flow rate of 52 g/10 min measured by extrusion plastometry per ASTM D1238 is not a direct melt viscosity value, but it correlates with lower torque in batch mixers and lower backpressure in hot-melt feed lines. High-vinyl-acetate EVA grades such as this one do not exhibit a single, sharp melting endotherm in differential scanning calorimetry because the comonomer interrupts long ethylene sequences. The thermal response is better described as a broad softening interval; published data for this specific configuration is limited, but ASTM D3418 is the appropriate test when a controlled thermal profile is required for quality control. Infrared spectroscopy can be used to confirm vinyl acetate content; the carbonyl absorption near 1740 cm⁻¹ correlates with the acetate level and is useful for incoming lot checks.
| Property | Typical value | Test method |
|---|---|---|
| Vinyl acetate content | 40 wt% | Manufacturer internal method |
| Melt flow rate | 52 g/10 min | ASTM D1238, 190 °C/2.16 kg |
| Density | 0.965 g/cm³ | ASTM D1505, 23 °C |
| Physical form | Pellets | Visual |
In compounding, a heated sigma-blade mixer or a twin-screw extruder with an L/D ratio of 24:1 is suitable. The feed throat should be cooled to prevent pellet bridging, a failure mode observed with high-vinyl-acetate resins because softening begins near 40 °C. A temperature setpoint of 150 °C to 180 °C is sufficient for melting; screw speed should remain below 200 min-1 if shear heating raises melt temperature toward 200 °C. Thermal degradation produces acetic acid and shifts color; therefore, nitrogen blanketing is recommended for transfer lines and storage tanks.
Incoming melt flow rate should be determined in triplicate per ASTM D1238; a variance of more than 5% between pellets and processed material may indicate moisture uptake, contamination, or thermal history differences. The density value of 0.965 g/cm³ is higher than conventional low-density polyethylene and lower than flexible PVC; it confirms lot-to-lot consistency when measured with a density gradient column or gas pycnometer according to ASTM D1505.
Hot-melt adhesive compounding with Elvax 40W commonly begins with preheating resin pellets in a jacketed mixer at 160 °C before adding wax at 5 wt% to 20 wt% of the formulation. Rosin ester tackifiers are added at 30 wt% to 50 wt%, and a hindered phenolic antioxidant at 0.25 wt% to 0.5 wt% is introduced before the wax to limit oxidative color development. The low melt viscosity of the grade permits uniform dispersion without high-shear rotor-stator mixers; a low-rpm double-arm mixer is often adequate. In packaging and bookbinding lines, the adhesive is applied at 165 °C to 175 °C.
A process conflict arises when high-speed lines require prolonged adhesive residence time in the melt tank: hold times above 6 h at 180 °C can produce gel particles and viscosity drift in steel tanks. Reducing hold temperature to 160 °C and using nitrogen blanketing lowers the rate of gel formation. Plant-scale failure in heated hose systems is often observed as char formation at dead zones behind thermocouple wells; no-dead-leg manifolds and flow-through ball valves reduce this risk. Substrate adhesion to corona-treated low-density polyethylene and polyester improves relative to 28% VA EVA, but adhesion to untreated polypropylene may remain insufficient without a primer or higher application temperature. When adhesive is applied by slot die at 180 °C, a gap setting of 0.2 mm to 0.3 mm controls coat weight, but adhesive stringing increases if the nozzle temperature falls below 160 °C because viscosity rises sharply. Air-open time in packaging lines at 25 °C and 50% relative humidity typically ranges from 2 s to 6 s, depending on wax content.
Substitution of Elvax 40W for a 28% vinyl acetate EVA shifts the adhesive balance toward elastomeric behavior rather than semicrystalline structural behavior. The increase in vinyl acetate from 28 wt% to 40 wt% reduces crystallinity and tensile modulus, increases elongation, and improves low-temperature flexibility. The higher melt flow rate lowers application viscosity more than a lower-melt-index grade of equal vinyl acetate content. As a result, open time and wetting improve, while green strength and elevated-temperature resistance decrease.
Formulators compensate for the loss of heat resistance by increasing wax content or selecting a higher-melting Fischer-Tropsch wax; the exact magnitude of the shift in ring-and-ball softening point per ASTM E28 depends on tackifier type and wax loading. If heat resistance must meet a 60 °C shear adhesion failure temperature per ASTM D4498, wax loadings above 20 wt% are generally required. The higher polarity also increases interaction with metallic surfaces; this is beneficial for aluminum and polyester bonding but may require formulation adjustments to prevent adhesive stringing during nozzle cutoff. Compared with EVA grades intended for blown film extrusion, Elvax 40W is not suited to high-speed film processes because low melt strength and aggressive adhesion to metal rolls cause web handling difficulties.
In wax modification, Elvax 40W is blended with paraffin or microcrystalline wax at 10 wt% to 30 wt% resin loadings. Jacketed tanks at 120 °C to 140 °C provide sufficient melting because the resin softens at lower temperatures; this range remains below the threshold for rapid deacetylation. The high vinyl acetate content allows higher resin loadings without phase separation compared to 18% VA EVA, and the high melt index produces a smaller viscosity increase than a 28% VA grade with melt index below 10 g/10 min. Wax coatings containing the resin are evaluated for low-temperature flexibility at -18 °C using mandrel bend tests in accordance with ASTM D3111.
In sealant formulations, the resin contributes elastomeric recovery and adhesion to concrete, aluminum, and wood; solvent-borne versions are possible because the resin is soluble in toluene and xylene at 20 °C. Solvent-borne sealants require leveling agents to control stringing during bead application. Hot-pour sealant formulations may combine 25 wt% EVA with oil, wax, and filler; application at 180 °C to 200 °C is used when substrate temperatures are below 10 °C to maintain wetting. Lower application temperature reduces thermal degradation but may reduce adhesion to cold concrete and metal surfaces.
Storage of Elvax 40W should be below 40 °C in a dry area. Pellets can agglomerate under silo pressure at ambient temperatures above 35 °C because of the resin’s low softening point. If pellets have been exposed to relative humidity above 60%, drying in a desiccant dryer at 60 °C for 4 h is recommended to reduce moisture below 0.1 wt% before extrusion. The resin is incompatible with strong Lewis acids and chlorinated oxidizers; molten storage in copper or brass components can accelerate formation of acetic acid by decomposition. For transfer lines and tanks, stainless steel 316L or nickel-plated steel is preferred.
Avoid adding amine-based additives at high temperature because amines can catalyze deacetylation and darken the melt. Long hold times above 180 °C or any exposure above 200 °C promote deacetylation with release of acetic acid; ventilation and closed-loop inert-gas blanketing are required. In batch operations, pot life at 175 °C is normally 4 h to 6 h before viscosity drift exceeds 10% in the absence of high-performance antioxidants. Viscosity stability can be monitored with a Brookfield Thermosel at 175 °C using spindle 27 at 10 min-1; drift above 10% indicates stabilizer depletion or localized overheating.
Food-contact status is governed by FDA 21 CFR 177.1350 for ethylene-vinyl acetate copolymers; compliance requires extraction testing of the finished adhesive or article, not merely the resin. Elvax 40W is typically covered by a REACH registration dossier under EC 1907/2006 and may be used in formulations subject to RoHS 2011/65/EU; no intentionally added lead, mercury, cadmium, hexavalent chromium, or polybrominated biphenyls are present. Users should verify that tackifiers, waxes, and stabilizers do not alter the final regulatory status. The resin is not classified as dangerous goods for transport under 49 CFR 173 and does not require a signal word label on safety data sheets; this does not eliminate the need for hot-melt burn hazard controls.
| Regulatory reference | Scope | Typical verification |
|---|---|---|
| FDA 21 CFR 177.1350 | EVA copolymers in food-contact articles | Extraction testing of finished article |
| EC 1907/2006 | REACH registration and SVHC | Manufacturer declaration |
| 2011/65/EU | RoHS heavy metal restrictions | XRF screening per IEC 62321 |
