| HS Code | 498390 |
| Vinyl Acetate Content | 9.5 wt% |
| Melt Flow Rate | 8 g/10 min (190°C/2.16 kg) |
| Density | 0.930 g/cm³ |
| Melting Point | 96°C |
| Crystallization Point | 66°C |
| Vicat Softening Point | 67°C |
| Tensile Strength At Break | 17 MPa |
| Elongation At Break | 800% |
| Flexural Modulus | 90 MPa |
| Shore D Hardness | 45 |
| Brittleness Temperature | -100°C |
| Water Absorption | 0.03% (24h) |
As an accredited ELVAX 770 Ethylene Vinyl Acetate Copolymer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | ELVAX 770 EVA copolymer: 25 kg bags, white pellets in multiwall paper sacks for safe transport and storage. |
| Container Loading (20′ FCL) | ELVAX 770 EVA copolymer loaded as full 20′ FCL, palletized, secured, moisture-protected, and stowed away from heat and sunlight. |
| Shipping | ELVAX 770 Ethylene Vinyl Acetate Copolymer is not regulated as a dangerous good for transport. It may ship as a non-hazardous resin in suitable packaging, avoiding dust generation. No UN number or hazard class applies. Ensure containers are clean, dry, and labeled with the product name. |
| Storage | Store ELVAX 770 Ethylene Vinyl Acetate Copolymer in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep containers tightly closed to prevent moisture contamination and dust accumulation. Avoid contact with strong oxidizers. Maintain moderate temperatures and protect from physical damage; proper storage ensures stability and safe handling. |
| Shelf Life | ELVAX 770 has a shelf life of at least two years when stored in original, unopened containers under cool, dry conditions. |
In packaging and bookbinding hot-melt formulation, the introduction of ELVAX 770 at 15–35 wt% of total compound mass places the formulation in the high-viscosity assembly-adhesive class because the grade carries a nominal vinyl acetate content of 9.5 wt% and a melt mass-flow rate of 0.8 g/10 min under ISO 1133-1:2022. The tackifier fraction is maintained at 30–45 wt% and the wax fraction at 20–35 wt%; typical tackifier systems are C5/C9 aliphatic-aromatic hydrocarbon resins or rosin ester derivatives, while the wax phase is paraffin or microcrystalline wax with a drop melting point between 65°C and 90°C. Antioxidant stabilisation uses a hindered phenolic primary antioxidant at 0.3–1.0 wt%. Regulatory clearance for indirect food-contact packaging adhesives is evaluated under FDA 21 CFR 175.105, with EU obligations under REACH Regulation (EC) No 1907/2006 and the RoHS Directive 2011/65/EU for restricted substances where the packaged product is an electrical or electronic article. Downstream compounding is run in a jacketed sigma-blade mixer at 160–180°C under nitrogen purge for 30–60 min; higher-output operations use a co-rotating twin-screw extruder with 40:1 L/D, screw speed 200–400 rpm, and a barrel profile from 120°C at the feed throat to 180°C at the die. Strand or underwater pelletising produces dry pellets with residual moisture below 0.05 wt%. At the converting stage, the adhesive is applied by slot-die or roll coater at 150–170°C to kraft liner, containerboard, or coated paper at line speeds from 250 m/min to 500 m/min. Terminal product types include corrugated case and carton side-seam and bottom-closure gluing, bookbinding spine glue, paper sack end seals, and paperboard tray erection adhesives. The main process failure mode is thermal deacetylation: sustained exposure above 200°C liberates acetic acid, raises acid number, and attacks copper-based machine components; wetted parts are therefore specified in 316L stainless steel or nickel-plated steel. Viscosity is controlled according to ASTM D3236, peel adhesion by ASTM D1876, and heat-fail resistance by ASTM D4498. Pre-drying at 60°C for 4 h is used when storage has exceeded 60% RH, because hydrolysis of the acetate group can shift viscosity and increase volatiles during extrusion. A recurring plant-scale issue on high-speed carton lines is char accumulation at the slot-die lip when startup temperature reaches 195°C before melt flow is established; the corrective sequence is a staged heat soak at 150°C for 20 min followed by ramp to setpoint.
The distinction between an unmodified paraffin wax and an EVA-modified wax compound becomes measurable at loadings of 1–5 wt% ELVAX 770 in corrugated paperboard saturation and at 5–15 wt% in high-build barrier coatings; candle over-dip bases are formulated at 30–50 wt% EVA in paraffin or microcrystalline wax. The copolymer undergoes phase separation within the crystallising wax network and forms a swollen polymer-rich phase that raises low-shear melt viscosity, improves scuff resistance, and reduces wax flaking at low temperatures without eliminating the moisture barrier. Compliance for food-contact coated paperboard is determined under FDA 21 CFR 176.170 for aqueous and fatty foods and FDA 21 CFR 176.180 for dry foods; the European framework is Regulation (EC) No 1935/2004 with member-state positive-list requirements for the specific wax and additive package. Production is performed in a jacketed blending kettle at 120–140°C using low-shear turbine agitation at 800–1,200 rpm for 45–90 min; the resin is pre-dispersed in a small portion of molten wax at 150°C before addition to the main kettle to prevent gel-particle formation. The melt is applied by immersion bath or curtain coater at 130–150°C, followed by forced-air cooling at 20–35°C. Terminal product types include wax-coated corrugated boxes for wet-process poultry and seafood, folded carton barrier coatings, paper cup side-seam wax, and candle over-dip layers. Process controls use ASTM F1249 for water-vapour transmission rate, ISO 534 for substrate thickness and coating-weight calculation, and ASTM D918 for blocking resistance under load. The upper holding temperature is 160°C; above this threshold paraffin oxidation and EVA chain scission accelerate, producing amber colour drift and a drop in heat-seal strength. The same grade is not selected as the principal polymer when high clarity is required in candle coatings because the dispersed EVA phase scatters light and produces a slight haze above 5 wt%; this is an operational boundary rather than a formulation defect.
Thermo-oxidative ageing in polymer-modified bitumen becomes process-limiting when ELVAX 770 is incorporated at 3–7 wt% of bitumen mass for paving binders and at 12–20 wt% for waterproofing membranes that require torch-applied or cold-adhesive installation. The 9.5 wt% vinyl acetate content contributes mainly to high-temperature stiffness and rutting resistance rather than to low-temperature elastic recovery; the grade is therefore selected for warm-climate wearing courses, airport aprons, bridge decks, and roofing underlayments where the binder must hold aggregates under standing load. Industry compliance for paving-grade polymer-modified bitumen is set by EN 14023:2010, with penetration resistance measured under ASTM D5/D5M, ring-and-ball softening point under ASTM D36/D36M, elastic recovery under ASTM D6084, and storage stability of the modified binder under EN 13399:2018. The downstream production sequence fluxes the base bitumen at 160°C, then introduces ELVAX 770 pellets through a high-shear rotor-stator mixer at 170–190°C and 4,000–5,000 rpm for 2–4 h. Terminal product types include highway wearing-course binders, bridge deck waterproofing membranes, airport apron binders, and polymer-modified bitumen roofing sheets. The central formulation threshold is phase topology: below 5 wt% the EVA-rich phase is dispersed in the bitumen matrix, but between 5–7 wt% a co-continuous network can form that produces a sharp increase in softening point and a simultaneous reduction in storage stability when the base bitumen contains a high asphaltene fraction. Processing above 200°C releases acetic acid from the acetate group, accelerates bitumen oxidation, and causes viscosity drift; after the high-shear stage, the blend is therefore held at 175–185°C in jacketed vessels and stored at 160–170°C under inert gas or slow agitation. Published data for phase-inversion behaviour in this specific low-VA grade at loadings beyond 8 wt% in heavily asphaltenic binders are limited, so trial batches with the local bitumen source are required before specifying a production range.
High-viscosity carrier resins for polyolefin masterbatch production are selected on the basis of melt-mass-flow rate, pellet integrity, and compatibility with the letdown resin. ELVAX 770 is used at 20–50 wt% of the masterbatch as a carrier for carbon black, slip, antiblock, or colour concentrates, while the letdown into blown or cast polyethylene film places the active additive at 0.5–5 wt% of final film mass. The production line uses a co-rotating twin-screw extruder with 40:1 L/D, a temperature profile from 140°C in the intake zone to 190–210°C at the die, and vacuum devolatilisation at -0.08 MPa; pellets are underwater-cut and dried to 0.05 wt% residual moisture before packaging. Industry compliance for general industrial use falls under REACH Regulation (EC) No 1907/2006; food-contact films made from the letdown compound are evaluated under EU No 10/2011 and FDA 21 CFR 177.1520 when the final film is polyethylene-based. Terminal product types include heavy-duty shipping sacks, agricultural greenhouse films, injection-moulded crates and pails, and masterbatch pellets sold to film extruders. The main process bottleneck is screw torque: because the 0.8 g/10 min melt-mass-flow rate is at the lower end of the range for carrier resins, high-torque drive packages and side-feeding at filler loadings above 30 wt% are required to prevent feed-throat blockage. Moisture must be kept below 0.05 wt% before extrusion because any free moisture in the feed section can produce surging at the die and pellet porosity. The masterbatch is not recommended for letdown resins with melt temperatures above 220°C because prolonged residence at that temperature can produce acetic acid odour and reduce carrier viscosity.
Melt strength deficiencies in conventional low-density polyethylene seal skins are addressed by blending 10–30 wt% ELVAX 770 into the sealant layer, while the grade can also be used as a neat skin where seal initiation must remain above 90°C to prevent blocking on the reel. The downstream process is cast coextrusion with melt temperatures of 240–260°C, an air gap of 50–100 mm, a die gap of 0.5–0.8 mm, and chill-roll temperature of 15–25°C; line speed is set between 150 m/min and 300 m/min depending on coating thickness and adhesion requirements. Industry compliance is anchored to FDA 21 CFR 177.1350 for ethylene-vinyl acetate copolymers in food contact, and to EU No 10/2011 with an overall migration limit of 10 mg/dm². Terminal product types include medical device pouch lamination webs, frozen-food film seal layers, bag-in-box inner liners, and paper/foil/polyethylene laminates for dry powders. Heat-seal strength is measured by ASTM F88, seal initiation temperature by ASTM F1921, and bond strength of laminated structures by ASTM F904. The main processing boundary in coextrusion is interfacial instability when the viscosity ratio between the sealant layer and the substrate polymer exceeds 3:1; ELVAX 770 is therefore premixed with LDPE to reduce the apparent viscosity before the die, and the die-lip temperature is held within 250–260°C while keeping residence time below 10 min. At high backpressure, screw speed is reduced rather than raising die temperature beyond 260°C, because deacetylation at the die lip causes smoke, gel specks, and loss of seal strength.
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ELVAX 770 ethylene vinyl acetate copolymer is a high-molecular-weight random copolymer containing 9.5 wt% vinyl acetate and 90.5 wt% ethylene. The grade has a melt mass-flow rate of 0.8 g/10 min measured at 190°C under a 2.16 kg load in accordance with ISO 1133-1:2022 or ASTM D1238 and a density of 0.930 g/cm³ determined by ASTM D792. These values place the product at the high-molecular-weight end of the low-vinyl-acetate ELVAX series, where melt flow rate decreases with increasing molecular weight at nearly constant comonomer level.
Published reference data for compression-moulded plaques include a DSC peak melting temperature near 95°C per ASTM D3418, Vicat softening temperature of approximately 79°C per ASTM D1525, Shore D hardness of approximately 48 per ASTM D2240, tensile strength at break of 18–21 MPa per ASTM D638, and elongation at break of 650–800%. These values are influenced by cooling rate, specimen thickness, and test speed; film and extrusion-coated specimens should not be assumed to match compression-moulded plaque data.
At 0.8 g/10 min, ELVAX 770 behaves as a high-viscosity extrusion grade. Single-screw extruders with screw L/D ratios of 24:1 to 30:1 and moderate compression ratios are commonly used; low-shear barrier screws are preferred because they reduce local viscous heating. Processing guidance indicates feed-zone temperatures below 160°C, compression-zone temperatures of 180–200°C, and melt temperatures of 210–230°C. Operation above 240°C accelerates thermal deacetylation of vinyl acetate groups, releasing acetic acid and producing gel defects in cast film. The high melt viscosity increases die head pressure and reduces output per screw revolution compared with grades of 7 g/10 min or 2 g/10 min. This viscosity increase is an intentional trade-off for higher melt tension: in extrusion coating, draw resonance onset is suppressed, neck-in is reduced, and higher draw-down ratios can be maintained at stable edge geometry. Non-vented extruders should be avoided when residence time at melt temperature exceeds 10 minutes, because acetic acid accumulation can form surface haze and pinholes.
Parallel-plate dynamic oscillatory measurements at 190°C under ISO 6721-10 show that the terminal relaxation time of ELVAX 770 is longer than that of a 2 g/10 min EVA grade. This is observed as a lower crossover frequency between storage modulus and loss modulus, indicating more elastic melt behavior. In practice, the higher melt elasticity improves bubble stability and reduces draw resonance, but it also increases die swell and can require wider die-gap settings in cast film and extrusion coating lines. Die gaps of 0.5–0.8 mm are common for low-MFR EVA coatings, with higher melt temperatures compensating for the increased viscosity.
Flexible packaging sealant layers based on ELVAX 770 are used in coextruded films where moderate seal initiation, high melt integrity, and low blocking are required. The 9.5 wt% vinyl acetate content lowers seal initiation relative to unmodified low-density polyethylene, but does not generate the blocking tendency observed with 18–25 wt% vinyl acetate grades. Blocking behavior should be evaluated by ASTM D3354. The low melt flow rate reduces thinning of the sealant layer during thermoforming and deep-draw packaging. However, it also limits flow into porous paper and foil surfaces; extrusion lamination onto paper or aluminum foil therefore requires melt temperatures above 210°C and higher nip pressures than are used with 7 g/10 min EVA sealants. Heat-seal performance should be evaluated with ASTM F88 on the finished film structure because seal initiation and hot-tack strength depend on sealant thickness, chill-roll temperature, and substrate heat capacity.
Blown film extrusion with ELVAX 770 is generally operated at blow-up ratios of 2.0:1 to 3.0:1 and frost-line heights adjusted to stabilize bubble geometry; the high melt strength permits a wider bubble stability window than that of 2 g/10 min grades. However, high molecular weight also increases retained orientation when the film is quenched below 20°C, and this can contribute to gauge variation and curl in monolayer structures. Gauge uniformity is typically controlled by internal bubble cooling and by maintaining a stable melt-temperature profile in the die; melt-temperature gradients greater than 10°C across the die are avoided.
Within the same supplier family, the principal differentiators are vinyl acetate content and melt flow rate. ELVAX 750 contains approximately 9.0 wt% vinyl acetate and has a melt flow rate of 7 g/10 min; ELVAX 760 contains approximately 9.3 wt% vinyl acetate and has a melt flow rate of 2 g/10 min. ELVAX 450 is a higher-polarity grade with 18 wt% vinyl acetate, and ELVAX 350 contains 25 wt% vinyl acetate. Table 1 summarizes the reference values, with melt flow rate measured at 190°C/2.16 kg per ASTM D1238.
| Grade | Nominal vinyl acetate content | Nominal melt mass-flow rate |
|---|---|---|
| ELVAX 750 | 9.0 wt% | 7 g/10 min |
| ELVAX 760 | 9.3 wt% | 2 g/10 min |
| ELVAX 770 | 9.5 wt% | 0.8 g/10 min |
| ELVAX 450 | 18 wt% | 8 g/10 min |
| ELVAX 350 | 25 wt% | 19 g/10 min |
ELVAX 770 has higher melt strength and melt tension than ELVAX 750 and ELVAX 760 at equivalent melt temperature. This suppresses draw resonance in extrusion coating and improves bubble stability in blown film, but it also increases extruder backpressure and limits throughput. Relative to ELVAX 450 and ELVAX 350, ELVAX 770 has lower polarity and poorer adhesion to polar substrates, but it has higher crystallinity, higher modulus, better heat resistance, and lower blocking. The selection of ELVAX 770 over a higher-vinyl acetate grade is therefore justified when stiffness, melt strength, and low blocking outweigh adhesion and low-temperature softness.
Compared with low-density polyethylene, ELVAX 770 has reduced crystallinity and a lower peak melting point, which lowers seal initiation and improves low-temperature impact strength. Compared with metallocene-catalyzed polyolefin plastomers, ELVAX 770 provides higher surface polarity through acetate side groups but lower oxidative stability at high temperature because the acetate structure is more susceptible to chain scission and crosslinking at sustained temperatures above 120°C than a fully hydrocarbon polyolefin. Published data for direct comparative seal-strength performance in identical multilayer film structures is limited, so the grade should be evaluated under ASTM F88 seal-strength protocols for the specific film construction.
ELVAX 770 functions as a carrier resin in filled masterbatches and flame-retardant compounds when higher melt strength is required to prevent strand breakage and to maintain filler dispersion under shear. The low melt flow rate increases local shear stress at constant screw speed, which can improve wetting of calcium carbonate, talc, and aluminum trihydrate compared with unmodified LDPE; however, the 9.5 wt% vinyl acetate level provides less polar wetting than 18 wt% vinyl acetate grades. In twin-screw compounding, torque limits are reached earlier than with higher-MFR carriers because of the higher melt viscosity. Typical carrier loadings fall between 50 wt% and 80 wt% of the polymer phase, with the remainder selected from LDPE or linear low-density polyethylene to control melt viscosity and cost. The grade is not an acid copolymer and therefore does not participate in zinc-neutralization ionomer chemistry.
ELVAX 770 differs from ethylene-butyl acrylate and ethylene-methyl acrylate copolymers in the type of polar functionality. The acetate group is less thermally stable than acrylate esters at elevated processing temperatures; heat-seal response can be compared under ASTM F88 protocols, with EVA typically sealing at a lower temperature than acrylate copolymers at equivalent comonomer content. Compared with ethylene-acrylic acid copolymers, ELVAX 770 lacks carboxylic acid functionality and cannot be ionically crosslinked or directly adhered to aluminum foil in extrusion lamination without a tie layer or adhesion promoter. Direct adhesion to aluminum foil can be evaluated by ASTM D903 peel testing; published comparative data for this grade in identical structures is limited.
Hot-melt adhesive formulations based on ELVAX 770 are less common than those based on higher-MFR grades because the 0.8 g/10 min melt flow rate limits wet-out on paper and films. Where high cohesive strength is required, the grade may be formulated at 20–35 wt% of the adhesive with waxes and tackifiers selected for compatibility with low vinyl acetate content. Application viscosity is higher than that of 7 g/10 min EVA adhesives, requiring heated hose and nozzle temperatures above 180°C. The maximum service temperature of the finished adhesive is limited by the crystalline melting point and creep behavior of the EVA phase, not solely by tackifier selection.
Thermal deacetylation of vinyl acetate groups becomes significant at melt temperatures above 230°C. The reaction releases acetic acid and produces unsaturation along the polymer chain; subsequent free-radical recombination can generate gel particles and die-lip deposits. Vented extruders with vacuum levels of 60–80 mbar at the vent port are preferred for removing low-molecular-weight volatiles. Residence time above 230°C should be limited to less than 10–15 minutes; repeated regrind exposure increases the concentration of pre-oxidized species and lowers the thermal threshold. Contact with copper or copper-containing alloys is avoided because acetic acid corrodes copper and the dissolved metal ions can catalyze further degradation. Acid-scavenging fillers such as calcium carbonate can reduce free acid, but zinc-containing additives should be reviewed carefully because zinc ions may accelerate deacetylation at temperatures above 220°C. Pre-drying is generally unnecessary at storage relative humidity below 50%; when surface condensation is possible at relative humidity above 70%, drying at 50–60°C for 2–4 hours reduces the risk of hydrolysis-induced melt viscosity drift.
Regulatory classification of ELVAX 770 is determined by the finished article and the specific additive package. The base ethylene-vinyl acetate copolymer may be used in food-contact layers subject to compliance with FDA 21 CFR 177.1350 and EU Regulation 10/2011, including the applicable total migration limit of 10 mg/dm² or 60 mg/kg under EU 10/2011. Manufacturer declarations for standard commercial formulations generally address REACH registration for the copolymer and RoHS 2011/65/EU restrictions, which limit lead, mercury, hexavalent chromium, PBB, and PBDE to 0.1 wt% and cadmium to 0.01 wt% in homogeneous materials. No medical or pharmaceutical packaging certification should be assumed without review of the specific grade, lot, and additive package.
In extruded profiles, gaskets, and wire-and-cable jacketing compounds, ELVAX 770 is incorporated at 5–20 wt% into polyethylene or polypropylene-based compounds to improve flexibility, impact strength, and filler acceptance. The high molecular weight of the EVA phase helps maintain elongation at break after mineral filler or flame-retardant loading; however, the same high viscosity requires close monitoring of extruder discharge pressure and melt temperature. Screen packs with filtration sizes finer than 100 mesh are generally avoided at high output because the resulting pressure rise can exceed the safe operating limit of older extruder clamp systems. Published data for specific extruder pressure limits in older systems is limited; equipment manufacturer pressure ratings should govern.
