| HS Code | 765431 |
| Vinyl Acetate Content | 40% |
| Melt Flow Rate | 52 g/10 min at 190°C/2.16 kg |
| Density | 0.965 g/cm³ |
| Tensile Strength At Break | 4.8 MPa |
| Elongation At Break | 900% |
| Hardness | 50 Shore A |
| Melting Point | 65°C |
| Vicat Softening Point | 38°C |
| Glass Transition Temperature | -30°C |
| Brittleness Temperature | -100°C |
| Chemical Family | Ethylene vinyl acetate (EVA) copolymer |
As an accredited Elvax 40W EVA Copolymer Resin,40% VA,High Elastomer Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged as 25 kg polyethylene-lined paper bags, 40% VA high elastomer grade, ensuring moisture protection and easy handling. |
| Container Loading (20′ FCL) | 20' FCL container loading of Elvax 40W EVA resin (40% VA, high elastomer grade), packed in bags, approximately 20 metric tons per container. |
| Shipping | Elvax 40W EVA resin ships as non-hazardous solid pellets in moisture-resistant bags or bulk containers. Protect from heat and humidity to prevent clumping. Store in a dry, ventilated area. Avoid direct sunlight and prolonged storage above 30°C. Standard freight with clean, covered transport is suitable. |
| Storage | Store Elvax 40W in a cool, dry, well-ventilated area away from heat, open flames, and direct sunlight. Keep containers tightly sealed to prevent moisture absorption, which can affect processing. Avoid prolonged elevated temperatures. Protect from physical damage and contamination. Under proper conditions, shelf life is typically at least one year from shipment. |
| Shelf Life | Shelf life is typically 2 years when stored in original packaging, away from heat, moisture, and direct sunlight. |
In high-speed case and carton closing operations where compression time remains below 0.8 s, hot-melt adhesive formulations based on Elvax 40W are typically compounded at resin loadings between 20 wt% and 35 wt%. The 40% vinyl acetate content depresses the crystalline melting point and broadens compatibility with rosin ester and terpene phenolic tackifiers, permitting lower application temperatures without sacrificing hot-tack strength. A representative blend comprises 20-35 wt% Elvax 40W, 30-45 wt% tackifying resin, 15-30 wt% Fischer-Tropsch or paraffin wax, and 0.5-1.0 wt% hindered phenolic antioxidant. Melt mass-flow rate of the resin is 2.5 dg/min at 190°C/2.16 kg according to ISO 1133-1:2022. Apparent viscosity is measured by ASTM D3236-19 using a Brookfield Thermosel with an SC4-27 spindle at 180°C; depending on wax type and tackifier softening point, readings usually fall between 400 mPa·s and 2500 mPa·s. Ring-and-ball softening point is tested in accordance with ASTM E28-99(2017), while thermal stability is screened by ASTM D4498-07 at 180°C for 24 h; viscosity drift beyond 10% or skin formation indicates antioxidant depletion. Processing is performed in jacketed sigma-blade mixers or twin-screw extruders at melt temperatures of 160-180°C; the high vinyl acetate content requires hold times below 4-6 h because deacetylation evolves acetic acid above 180°C and leads to viscosity drift, darkening, and carbonized gel particles at nozzle tips. Applicator systems using heated gear pumps with displacements of 1.5-3 cc/rev, slot nozzles, and wheel or jet applicators operate at 160-175°C. The open-time window, typically 2-8 s at 160°C, is controlled by wax crystallisation kinetics and must be revalidated on each packaging line because board surface energy, ambient temperature, and compression pressure alter the bond-failure mode from cohesive to adhesive. Terminal formats include case and carton sealing for deep-freeze food packaging, tray erection, bookbinding spines, and corrugated container assembly. Regulatory compliance for indirect food contact is framed by FDA 21 CFR 175.105 for adhesives, 21 CFR 176.170 and 21 CFR 176.180 for paperboard, EC 1935/2004, and REACH.
Halogen-free flame-retardant cable compounds using Elvax 40W as the elastomeric matrix are formulated with aluminium trihydrate or magnesium dihydrate at total filler loadings between 55 wt% and 65 wt%. The resin addition ratio commonly ranges from 15 wt% to 30 wt%, with an additional 2-5 wt% silane-grafted EVA or maleic anhydride-grafted polyolefin coupling agent and 0.5-1.5 wt% processing stabiliser. The polar 40% vinyl acetate content promotes filler wetting, but the practical filler ceiling is determined by two competing factors: the endothermic release of water from ATH starting at approximately 180°C and the rapid increase in low-shear viscosity as the mineral packing fraction approaches the maximum packing limit of the filler particle size distribution. Compounding is conducted on a co-rotating intermeshing twin-screw extruder with an L/D ratio of 40:1 to 52:1, barrel temperatures from 120°C at the feed throat to 170°C at the die, and a vacuum vent operated at -0.08 MPa to strip residual moisture. Fillers are pre-dried to <0.1 wt% moisture at 80°C for 4-8 h; insufficient drying produces surface porosity and pinholes during cable extrusion. Downstream cable manufacture uses a single-screw extruder with L/D 24:1 to 30:1 and a low compression screw of 1.2:1 to 1.8:1 to limit shear heating, with melt temperatures held between 150°C and 180°C. The melt is discharged through a crosshead die onto copper or aluminium conductors, followed by water trough cooling and spark testing. Terminal products include low-smoke zero-halogen insulation and sheathing for control cable, signalling cable, building wire, and rail transit fixed wiring. At filler loadings above 65 wt%, elongation at break falls below the tensile elongation limits of many cable standards, and melt pressure at the die head may exceed the extrusion line pressure rating of 20-25 MPa, making stable jacket thickness control unreliable.
| Test designation | Parameter | Typical acceptance boundary |
|---|---|---|
| IEC 60754-1:2011 | Halogen acid gas content | < 0.5% HCl equivalent |
| IEC 60754-2:2019 | Gas acidity | pH ≥ 4.3, conductivity ≤ 10 µS/mm |
| IEC 61034-2 | Smoke density | Light transmittance > 60% |
| EN 50399:2022 | Flame spread and heat release | CPR Euroclass, e.g. B2ca-s1a,d0,a1 |
Mechanical properties are tested according to IEC 60811-501 for tensile strength and elongation before and after thermal ageing. Compliance additionally references IEC 60754-1:2011 for halogen acid gas, IEC 60754-2:2019 for gas acidity, IEC 61034-2 for smoke density, and EN 50399:2022 for flame spread under the Construction Products Regulation. Formulation and processing boundaries are therefore set by both the endothermic filler decomposition threshold and the residence-time sensitivity of the EVA matrix. When the compounding line starts or shuts down, barrel temperatures above 180°C must be avoided unless the vent system is maintained at full vacuum; otherwise acetic acid vapour condenses in the vent port and causes feed instability on the subsequent batch.
When cold-flex requirements for torch-applied and self-adhered roofing membranes are specified below -20°C, Elvax 40W is introduced into the bitumen compound at 3-8 wt% to reduce low-temperature brittleness and increase softening point. The modification is carried out in a vertical high-shear rotor-stator mixer or a horizontal kneader heated to 180-190°C; the resin is metered in pellet form after the bitumen has reached 170°C, and mixing continues for 2-4 h until a continuous polymer-rich phase is observed in fluorescence microscopy of a quenched film. Below 3 wt%, improvement in cold bending is marginal, while above 8 wt%, compound viscosity at 180°C rises steeply and may exceed the capability of a standard gear pump rated for 10,000-15,000 mPa·s. Softening point is measured by ASTM D36, penetration by ASTM D5, and cold bending by EN 1109 or ASTM D5147. The modified compound is subsequently coated or calendered onto polyester mat or glass fleece reinforcement, then surfaced with slate granules, sand, or polyolefin film. Terminal product forms include flexible sheets for roof waterproofing under EN 13707:2004+A2:2009, bitumen dampproofing sheets under EN 13969:2004, and polymer-modified asphalt mastics applied by trowel. Compliance also includes REACH and, for North American specifications, ASTM D6222/D6222M-16. Storage stability is evaluated by EN 13399 or ASTM D7173; because the high vinyl acetate segment is thermally sensitive, storage tanks are maintained at 160°C under slow agitation, and a nitrogen blanket is recommended when storage exceeds 8 h.
The compound uses Elvax 40W at 8-15 wt% as a high-polarity binder for mineral fillers such as barium sulphate and calcium carbonate, which are loaded at 70-85 wt% to increase mass per unit area. A processing oil or phthalate-free plasticiser may be incorporated at 2-5 wt%, and carbon black at 0.5-2 wt% is used as a processing aid and UV shield. Mixing is carried out in an intermeshing internal mixer with a fill factor of 0.70-0.80 and rotor speeds of 30-60 rpm, with chamber temperature set to 120-160°C. The batch is discharged as a preformed strip and fed through a two-roll mill or short extruder into a three-roll calender; sheet thickness is typically 1-4 mm. Because the mineral phase raises density to 2.0-2.5 g/cm³ and reduces melt strength, edge cracking at the calender can occur when the sheet is drawn below 1 mm or when roll temperature falls below 80°C. Fillers must be dried to <0.05 wt% moisture at 80-100°C because residual water generates blisters during calendering. Terminal formats are automotive dash inner insulators, floor barrier sheets, rear parcel shelf pads, and appliance damping mats. Compliance is nested under IATF 16949:2016 for automotive supplier quality and ECE R118 for burning behaviour of interior materials; volatile organic compound and fogging behaviour are tested according to VDA 278 and DIN 75201. Published dynamic mechanical loss-factor data for this specific resin-filler coupling configuration are limited, so material development programmes should validate acoustic transmission loss on unconsolidated sheet samples rather than extrapolating from unmodified EVA grades.
For flexible packaging lines running at seal-bar temperatures between 85°C and 120°C, Elvax 40W is employed as the primary seal-layer resin at 60-90 wt% of the layer, with the balance composed of slip/antiblock masterbatch, low-molecular-weight hydrocarbon resin, or polyolefin diluents. The high 40% vinyl acetate content reduces the heat-seal initiation temperature relative to lower-VA EVA grades, enabling coextruded lidding films to seal through product contamination at lower bar pressure. Heat-seal strength is evaluated according to ASTM F88/F88M-21 on 25 mm wide test strips cut parallel to the machine direction; seal strength values are typically reported between 8 N/25 mm and 25 N/25 mm depending on substrate, coating weight, and dwell time. Production is carried out by coextrusion cast film or extrusion coating on a 3-layer or 5-layer flat die with melt temperatures of 150-180°C; the chill roll is held at 15-25°C to prevent blocking. For extrusion lamination, the resin layer is applied at 10-30 µm coating weight onto aluminium foil, polyester, or oriented polypropylene. Terminal products include dairy lidding film, pharmaceutical strip packaging, barrier pouches for medical devices, and frozen-food overwrap. Food-contact compliance is governed by FDA 21 CFR 177.1350 for ethylene-vinyl acetate copolymers, EU Commission Regulation (EU) No 10/2011 with overall migration limits tested under OM2, and REACH. The operational boundary is set by high-temperature stability: melt temperatures above 180°C, particularly in long residence-time extrusion coating lines, initiate deacetylation, which imparts an acidic odour and can cause polyethylene terephthalate or foil adhesion failure at the lamination nip. Start-up and shutdown purges should therefore be kept below 15 min at full temperature.
The addition of Elvax 40W to refined paraffin or microcrystalline wax at 5-20 wt% modifies low-temperature toughness, gloss retention, and resistance to flaking in wax-coated corrugated packaging. The blending sequence uses a jacketed kettle at 120-140°C with a disperser impeller; pellets are added to the molten wax under moderate agitation and held for 30-60 min until clarity is reached. Higher addition levels above 20 wt% raise melt viscosity beyond the practical limit for curtain coating, typically 50-150 mPa·s at 100°C, and may require pressure filtration through 100-200 µm screen packs. Coating weight is controlled by a gravimetric or doctored coating head at 5-15 g/m², and cold crack resistance is inspected by folding coated board at -10°C. Terminal use includes wax-impregnated corrugated produce boxes, industrial paper wraps, and food-contact paperboard where compliance is assessed under FDA 21 CFR 176.170 and 21 CFR 176.180. The high vinyl acetate content improves oil retention in the wax matrix, but published numerical data for this specific grade in wax saturating applications are limited; therefore, bend-test validation on the production line is required for each board substrate.
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Elvax 40W is an ethylene-vinyl acetate copolymer resin containing a nominal vinyl acetate comonomer content of 40 wt% and is classified as a high-elastomer EVA grade. The polymer is supplied as pellets for hot-melt adhesive compounding, sealant formulation, wax modification, and polymer blending. Published typical values from the manufacturer’s technical data include a melt flow rate of 52 g/10 min at 190°C under a 2.16 kg load measured according to ISO 1133-1:2022 / ASTM D1238-20, a density of 0.965 g/cm³ under ISO 1183-1:2019 / ASTM D792-20, tensile strength at break in the range of 5–6 MPa and elongation at break of 1000% under ISO 527-2:2012 / ASTM D638-14, Shore A hardness of 40 under ISO 48-4:2018 / ASTM D2240-15(2021), and ring-and-ball softening point of approximately 104°C under ASTM E28-18. These values are typical lot data, not release specifications; the certificate of analysis for the supplied batch controls conformance.
| Property | Test method | Typical value |
|---|---|---|
| Vinyl acetate content | Manufacturer internal thermogravimetric/FTIR method | 40 wt% |
| Melt flow rate | ISO 1133-1:2022 / ASTM D1238-20 | 52 g/10 min at 190°C, 2.16 kg |
| Density | ISO 1183-1:2019 / ASTM D792-20 | 0.965 g/cm³ |
| Tensile strength at break | ISO 527-2:2012 / ASTM D638-14 | approx. 5–6 MPa |
| Elongation at break | ISO 527-2:2012 / ASTM D638-14 | 1000% |
| Shore A hardness | ISO 48-4:2018 / ASTM D2240-15(2021) | 40 |
| Ring-and-ball softening point | ASTM E28-18 | approx. 104°C |
The elevated vinyl acetate content alters the crystalline–amorphous balance of the ethylene backbone. Differential scanning calorimetry shows a broad melting endotherm rather than the sharp crystalline melt associated with low-vinyl-acetate ethylene copolymers. The reduction in polyethylene-type crystallinity produces the Shore A hardness of 40, the high elongation at break, and pronounced low-temperature flexibility observed on production-scale adhesive lines. The polar acetate groups also increase interaction with polar substrates such as corona-treated polyester, anodized aluminium, and glass. The same polarity broadens solubility in ketones, esters, aromatic hydrocarbons, and selected alicyclic solvents, which is exploited in solvent-borne adhesives and gravure coating binders.
The principal difference between Elvax 40W and lower-vinyl-acetate EVA grades is the suppression of crystallinity and the corresponding shift toward elastomeric behaviour. A grade at 25 wt% vinyl acetate retains greater room-temperature stiffness and higher tensile strength, while a grade at 18 wt% vinyl acetate is harder and more resistant to creep at elevated service temperature. Elvax 40W, by contrast, delivers greater surface tack, better wetting of polar films, and a softer failure mode. The melt flow rate of 52 g/10 min also differentiates it from lower-flow grades used in blown film or extrusion lamination; the higher flow reduces melt pressure in narrow slot die coating and permits lower processing temperatures in hot-melt mixing.
When compared with a 28 wt% vinyl acetate grade of lower melt flow rate, Elvax 40W shows lower elastic recovery and lower cohesive strength after hot-melt setting. This makes it suitable as a high-tack component in formulations where rapid polar-substrate wetting is more important than high shear resistance. In contrast, a lower-VA grade is preferred when a bond must retain holding power under constant load in a warm warehouse. These differences are evaluated on production lines through peel adhesion tests on aluminium foil or treated PET film using 90° or 180° geometries adapted from ASTM D6862-11 and ASTM D903-98(2022). The measured values are formulation-dependent because tackifier and wax ratios modulate the final adhesive hardness, set speed, and thermal resistance.
The high vinyl acetate level also alters melt rheology. At a given temperature, Elvax 40W exhibits a lower zero-shear viscosity than a low-MI EVA with the same comonomer content, but its polar interactions can produce more pronounced shear thinning when compounded with rosin ester tackifiers. Rotational rheometry using parallel-plate geometry at 160°C and 1 rad/s is used on some compounding lines to monitor the influence of tackifier acidity on the EVA phase. Batch-to-batch variation in tackifier acid number, typically 5–15 mg KOH/g for rosin esters, can shift the apparent cross-link density or cause catalytic ester exchange during extended heating; this is a practical reason to control incoming tackifier quality rather than to rely solely on resin specification.
Hot-melt processing of Elvax 40W is commonly performed in jacketed vertical or sigma-blade mixers at 150–180°C. The upper temperature limit is governed by the onset of acetic acid elimination from the vinyl acetate comonomer. In production trials on a 500 L nitrogen-blanketed holding tank, melt held at temperatures exceeding 180°C for more than 4 h has shown measurable viscosity drift and the development of an acrid odour. The degradation route is deacetylation followed by chain scission and colour formation; it accelerates as liberated acetic acid lowers the local pH in the melt. A nitrogen cover and a short first-in, first-out melt schedule are common controls on continuous coating lines.
Stabilization is usually achieved with a hindered phenolic primary antioxidant and a phosphite secondary antioxidant at combined loadings of 0.1–0.3 wt%. The exact package must be validated in the full adhesive formulation because acidic tackifiers and fillers can deactivate certain phosphites. Quality-control laboratories track viscosity stability on a cone-and-plate rheometer at 160°C and monitor the carbonyl index after accelerated ageing at 150°C in forced-air ovens. A rise in carbonyl absorbance above a formulation-specific threshold indicates deacetylation and oxidative degradation; this is a more reliable control than visual colour alone because some tackifiers darken without creating acidic decomposition products.
For slot-die adhesive coating, the melt temperature at the die is normally maintained between 150°C and 180°C to achieve uniform coat weight without exceeding the degradation threshold. The melt flow rate of 52 g/10 min permits low melt pressure in die internal cavities, but it also reduces the film strength of the applied molten layer before setting. Coaters handling low-VA grades at higher temperatures may need to lower the die temperature by 10–20°C when switching to Elvax 40W. The same principle applies to extrusion of tapes and profiles: barrel settings should not copy higher-melting polyolefin profiles, and the feed zone should remain below 40°C to prevent pellet bridging.
Moisture management is another boundary condition. Although EVA is not as hygroscopic as polyamide or TPU, the high vinyl acetate content increases moisture uptake relative to nonpolar polyethylene. Pellets stored in humid warehouses can adsorb surface moisture, which may hydrolyse ester groups during extended hot-melt hold times and create surface defects in extruded profiles. A desiccant dryer operating at 55–65°C for 4 h is a standard precaution when ambient relative humidity exceeds 60% or when the finished surface must meet strict visual criteria. The use of a nitrogen blanket on the melt also reduces hydrolytic degradation by displacing humid air at the melt surface.
Elvax 40W is used as a flexibilising modifier in compounds based on PVC, polyolefin recyclates, bitumen, and selected engineering thermoplastics. Dispersion is best achieved in a co-rotating twin-screw extruder with an L/D ratio of 44:1 and a screw profile that includes kneading blocks in at least two zones. The polar vinyl acetate groups promote compatibility with chlorinated polymers and with polyolefin matrices that contain oxidized or maleated fractions. In PVC sheet modification, the resin is typically added at 10–30 phr to improve low-temperature impact; the exact loading depends on the plasticizer system and the desired hardness. Mechanical property validation is performed under ISO 527-2:2012 for tensile behaviour and ISO 6721-10:2015 for dynamic mechanical analysis.
The high melt flow of Elvax 40W does not guarantee simple feeding. Pellet surface softening at feed-zone temperatures above 40°C has caused bridging and flow interruptions in dilute-phase conveying systems on production lines handling this grade. A cooled feed throat and a grooved barrel section are standard. In addition, the resin should not be preblended with calcium carbonate or other acid-sensitive fillers in a high-shear mixer for long periods because local heating can generate traces of acetic acid that attack filler surfaces and increase die lip build-up. If calcium carbonate is required, it is usually introduced downstream in the twin-screw process, after the EVA has fully melted and been dispersed into the matrix.
In bitumen modification, Elvax 40W is dispersed into hot bitumen at 160–180°C in a rotor-stator mixer or a high-torque paddle mixer. The high VA content improves low-temperature elastic recovery of the modified binder, but it also increases storage viscosity more than an equivalent loading of a lower-VA EVA. Addition levels are usually kept below 5 wt% of the binder to avoid phase separation or excessive viscosity build. Storage stability is tested by a tube test at 180°C for 72 h, with the difference in softening point between top and bottom sections used as a control metric. Published data for this specific configuration are limited because local bitumen composition and asphaltene content strongly influence the result; pilot testing is therefore required before production implementation.
Polymer modification also benefits from the elastomeric character of the 40 wt% vinyl acetate comonomer. In polyolefin recyclate streams, addition of Elvax 40W at 5–15 wt% can reduce brittle failure and improve weld-line strength in injection-moulded parts. The process is performed on injection moulding machines with clamp force settings between 800 kN and 1200 kN for medium-sized parts, with melt temperature typically between 130°C and 160°C. Higher melt temperatures are avoided to limit deacetylation. The resulting compound is evaluated by notched Izod impact testing under ISO 180:2019 / ASTM D256-10 and by melt flow rate measurement under ISO 1133-1:2022. These data allow the compounder to adjust let-down ratios without pushing the blend into an overly soft, creep-sensitive region.
For solvent-borne adhesive applications, Elvax 40W is commonly dissolved in toluene or methyl ethyl ketone at 20–30 wt% solids using a high-torque anchor stirrer operating at 60–80 rpm. The high acetate content reduces the energy input required to reach a clear solution compared with lower-VA EVA grades, but the resulting solution remains sensitive to moisture condensation during storage because both the polar solvent and the polar comonomer attract atmospheric water. In gravure printing inks and overprint varnishes, the resin is used as a binder component where low-temperature flexibility and pigment wetting are required. The finished ink should be filtered through a 10 μm absolute filter after letdown to remove microgel particles that may form if the solution is overheated above 60°C during dilution. Food-contact status must be evaluated on the finished article because migration limits are governed by the complete adhesive or ink system under FDA 21 CFR 175.105, FDA 21 CFR 177.1350, or EU Regulation 10/2011 as applicable.
The resin should not be combined with amine-based additives without preliminary oven ageing. Although amine stabilizers are effective in some polyolefin systems, they can contribute to colour instability in high-VA EVA melts because the amine functionality interacts with acidic decomposition products. Accelerated ageing at 150°C in a forced-air oven for 7 days is a practical screening test for additive packages intended for long-term hot-melt stability. If a formulation requires a nitrogen-containing rheology modifier or adhesion promoter, the supplier’s technical recommendation should be confirmed by measuring colour change, acidity, and melt viscosity retention in the full compound rather than in the neat resin.
