| HS Code | 816267 |
| Resin Type | Ethylene Vinyl Acetate (EVA) Copolymer |
| Vinyl Acetate Content | 12% |
| Density | 0.936 g/cm³ |
| Melt Flow Rate | 0.35 g/10 min (190°C/2.16 kg) |
| Melting Point Dsc | 96°C |
| Vicat Softening Point | 88°C |
| Tensile Strength At Break | 24.5 MPa |
| Elongation At Break | 750% |
| Flexural Modulus | 160 MPa |
| Hardness Shore D | 45 |
| Brittleness Temperature | -100°C |
As an accredited ELVAX 670 Ethylene Vinyl Acetate Copolymer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | ELVAX 670 Ethylene Vinyl Acetate Copolymer supplied as translucent pellets in 25 kg polyethylene-lined paper bags. |
| Container Loading (20′ FCL) | 20′ FCL: palletized ELVAX 670 copolymer bags loaded, secured, and containerized for safe, dry transport. |
| Shipping | ELVAX 670 is shipped as solid pellets in multiwall paper bags, drums, or supersacks. It is non-hazardous and not regulated for transport. To prevent clumping and moisture uptake, keep containers sealed in a dry environment. Store away from heat sources and direct sunlight. |
| Storage | Store ELVAX 670 Ethylene Vinyl Acetate Copolymer in a cool, dry, well-ventilated area away from direct sunlight, heat, ignition sources, and strong oxidizers. Keep containers tightly sealed to prevent moisture pickup, dust accumulation, and contamination. Avoid prolonged storage above ambient temperatures to prevent pellet bridging. Follow good housekeeping and first-in/first-out stock rotation. |
| Shelf Life | Shelf life is typically 2 years if stored sealed in a cool, dry place away from direct sunlight and heat. |
ELVAX 670 is processed as a low-vinyl-acetate ethylene copolymer with nominal 12 wt% vinyl acetate and a melt index of 2.0 dg/min when measured at 190°C under 2.16 kg according to ASTM D1238. The grade's high melt elasticity and low comonomer content place it between low-density polyethylene and higher-VA flexible EVA grades, meaning that screw design, die pressure, melt-temperature rise, and draw-down stability must be evaluated separately for each downstream conversion line rather than assumed from higher-MI EVA processing conditions.
In heavy-duty industrial blown film, ELVAX 670 is typically blended with LLDPE or LDPE at 20-40 wt% to raise dart impact strength and bubble stability while retaining heat-seal behavior. The blend is dry-mixed and processed on a grooved-feed single-screw extruder with an L/D of 24:1 to 30:1 and a die gap of 0.8-1.2 mm; melt temperature is controlled at 175-205°C with blow-up ratio between 2.0:1 and 2.5:1. On production-scale lines, lowering die adapter temperature below 160°C has been associated with melt fracture at the die lip and gauge bands in the film, while excessive melt temperature above 220°C accelerates vinyl acetate degradation and increases back-pressure fluctuation. Food-contact compliance is governed by FDA 21 CFR 177.1350 and Commission Regulation (EU) No 10/2011, with overall migration limits applicable to the finished article. Terminal finished product types include freezer-grade shipping sacks, heavy-duty mailers, and surface protection films where low-temperature puncture resistance is measured by ASTM D5748.
In additive masterbatch compounding for polyolefin films and extrusion coating, ELVAX 670 functions as a high-viscosity carrier resin at 25-35 wt% of total masterbatch, with pigment loading between 40-60 wt% and a dispersing wax package at 5-10 wt%. On a co-rotating twin-screw extruder with an L/D of 40:1 and zone temperatures from 130°C to 180°C, the carrier phase undergoes a reduction in apparent melt viscosity as filler volume fraction declines at carrier loadings above 35 wt%; dispersion improves, but pellet hardness falls, causing hopper bridging and dosing auger slip in downstream feeding equipment. Vacuum degassing at -0.08 MPa is used to remove volatiles from wax and pigment pre-wetting agents. Compliance for the compounded intermediate is managed under REACH (EC 1907/2006) and RoHS Directive 2011/65/EU; if the final film or coating is food-contact, the masterbatch formulation must satisfy FDA 21 CFR 177.1350 and EU Regulation 10/2011 migration limits. Published data for this specific grade in high-filler masterbatches is limited, so masterbatch makers typically validate pellet crush strength and melt pressure during scale-up. Terminal finished product types include polyethylene film color concentrates, additive masterbatches for extrusion coating, and flame-retardant masterbatches for non-food industrial films.
Compression-set requirements in extruded automotive and construction sealing profiles lead compounders to replace a portion of the polyolefin elastomer with ELVAX 670 at 70-90 phr, with LLDPE or POE at 10-30 phr to adjust flexural modulus and low-temperature ductility. The dry blend is run on a profile extruder with an L/D of 24:1 to 28:1 and a Maddock-style mixing screw, with barrel temperatures from 150°C at the feed zone to 205°C at the die, followed by vacuum sizing and water cooling. Operators monitor die swell and shrinkage because high melt elasticity of ELVAX 670 can generate dimensional deviation in thin walls below 1.2 mm. Compliance testing for mechanical properties is conducted according to ISO 527-2 tensile and ISO 868 hardness; aging resistance is evaluated under ISO 188, and environmental compliance is checked against REACH and RoHS Directive 2011/65/EU. Published data for this specific grade in dynamic weather aging is limited, and outdoor profiles require UV stabilizer packages because low-VA EVA without carbon black is susceptible to photo-oxidation. Terminal finished product types include automotive door seal carriers, construction glazing gaskets, and edge-protection profiles.
In polymer-modified bitumen for waterproofing membranes and heavy-traffic paving binder, ELVAX 670 is evaluated at 3-6 wt% of total bitumen with addition into a heated high-shear mixer at 170-190°C. Digestion time of 2-4 h is required for dispersed-phase swelling and phase inversion; formulations without sufficient aromatic dispersing agent show polymer separation during static storage at 180°C when EVA addition exceeds 7 wt%, creating a distinct polymer-rich skin at the tank surface. The low vinyl acetate content contributes to high-temperature rutting resistance but produces less low-temperature flexibility than higher-VA EVA or SBS modification. Specification testing includes EN 13707 for flexible sheets, ASTM D36 softening point, and ASTM D7175 rheological characterization under a dynamic shear rheometer. Compliance for construction products additionally follows REACH and regional building-material emission requirements. Published data for this specific low-VA EVA grade in bitumen modification is more limited than for 18-28 wt% VA EVA grades; plant-scale validation should include 48 h storage stability and temperature-sweep rheology. Terminal finished product types include torch-applied waterproofing membranes and polymer-modified asphalt binder for high-load intersections.
Extrusion lamination operations introduce ELVAX 670 into the seal layer of flexible packaging at 15-30 wt% in combination with LDPE or LLDPE, extruded as a 10-20 μm molten web onto paper, aluminum foil, or oriented polypropylene. The resin is processed on a single-screw extruder with an L/D of 26:1, a flat die matched to the substrate width, and melt temperature controlled between 240°C and 280°C; production-scale lines show that exceeding 300°C accelerates vinyl acetate elimination, producing an acrid odor and building deposit on the chill roll, while melt temperatures below 230°C reduce adhesion to foil due to insufficient thermal activation. Food-contact status is controlled by FDA 21 CFR 177.1350 and Commission Regulation (EU) No 10/2011, with migration testing based on the food category and time/temperature conditions of use. Seal performance is tested using ASTM F88 for seal strength and ASTM F1921 for hot-tack properties. Terminal finished product types include hot-fill lidding films, peelable seals, and high-stiffness laminate inner webs where the low-VA content raises seal-initiation temperature relative to higher-VA grades and prevents seal deformation in high-temperature filling lines.
Injection molding of flexible cable grommets, end caps, and vibration-damping mounts uses ELVAX 670 at 85-100 phr, with up to 15 phr of polypropylene or LDPE to increase modulus and reduce cycle time. The material is run on a reciprocating-screw injection molding machine with a 20:1 to 24:1 L/D barrel, compression ratio between 2.0:1 and 2.5:1, and injection pressure calculated from projected area at 30-60 MPa. Melt temperature is maintained at 180-220°C with mold temperature from 20°C to 40°C; because EVA has low thermal conductivity, cooling time rather than injection speed becomes the cycle-limiting parameter. Thin sections below 1.0 mm show freeze-off before complete packing on single-gate tools, causing sink marks and weld-line brittleness. If ambient storage RH exceeds 60%, surface moisture on pellets should be removed by drying at 60°C for 4 h to avoid splay defects. Compliance includes ISO 180 Izod impact strength, ISO 75/A heat deflection temperature, REACH, and RoHS Directive 2011/65/EU; electrical enclosure components additionally require IEC 60695-2-11 glow-wire testing when specified by the end application. Published data for ELVAX 670 in injection-molded technical parts is limited, so mold-flow simulation with grade-specific viscosity data is required before tool construction. Terminal finished product types include appliance cable grommets, protective end caps, and anti-vibration mounts.
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ELVAX 670 is an ethylene-vinyl acetate (EVA) copolymer resin supplied as solid pellets, with a nominal vinyl acetate incorporation of 12 wt% and a CAS registry number of 24937-78-8. The grade is part of the Elvax product family and is used in coextruded flexible packaging, blown film, extrusion coating, and high-viscosity compounding. The polymer is a random ethylene-vinyl acetate copolymer; the acetate side groups reduce polyethylene lamellar thickness and crystallinity. At 12 wt% vinyl acetate, the material retains a higher crystalline fraction than 18–28 wt% VA grades and therefore exhibits higher stiffness, higher melting point, and reduced low-temperature sealability relative to those higher-VA copolymers. The defining rheological feature is a nominal melt flow rate of 0.35 g/10 min at 190 °C and 2.16 kg load, measured in accordance with ASTM D1238. This low melt index corresponds to high average molecular weight and high zero-shear viscosity, which increases melt strength but also raises extruder backpressure. End-use properties should be confirmed against the supplier certificate of analysis, because the listed values are nominal and are not specification limits.
For ELVAX 670, standard reference data are generated using the methods shown in Table 1. The vinyl acetate content is controlled during copolymerization and is routinely quantified by Fourier-transform infrared spectroscopy using ASTM D5594. The melt flow rate is the primary grade-differentiating variable within the 12 wt% VA Elvax series. The density value is slightly below the density of low-density polyethylene and is consistent with the short-chain branching contribution of the acetate group. The differential scanning calorimetry peak melting point is depressed relative to high-density polyethylene because the acetate side groups reduce the average lamellar thickness. Typical unfilled 12 wt% VA low-melt-index EVA tensile behavior is characterized by tensile strength at break in the range of 15–20 MPa and elongation at break above 600% when measured under ASTM D638 Type IV at 50 mm/min; these are class values and do not replace lot-specific data. The data in Table 1 are suitable for preliminary material selection only; lot-specific values may vary within production control limits and should be verified before tooling or process conditions are fixed.
| Property | Test method | Nominal value |
|---|---|---|
| Vinyl acetate content | ASTM D5594 | 12 wt% |
| Melt flow rate | ASTM D1238 | 0.35 g/10 min at 190 °C / 2.16 kg |
| Density | ASTM D792 | 0.933 g/cm³ |
| DSC peak melting point | ASTM D3418 | 96 °C |
At melt temperatures above 230 °C, ethylene-vinyl acetate copolymers degrade predominantly by deacetylation. Acetic acid evolution accelerates sharply above this threshold and can produce corrosive head-space condensate, surface bubbles, discoloration, and a measurable shift in melt viscosity. For ELVAX 670, the practical processing window is therefore bounded on the upper side by thermal residence time and on the lower side by the onset of melt fracture. On single-screw extruders with a 24:1 to 30:1 L/D barrier screw and a compression ratio near 3.0:1, barrel settings are typically arranged in a flat or mildly reversed profile from 170 °C in the feed zone to 200–210 °C in the metering zone. Adapter and die zones are held no more than 10 °C above the metering temperature, and melt temperature is verified with an immersed thermocouple after the screen changer.
The 0.35 g/10 min melt flow rate creates high screw torque and high melt pressure at the breaker plate. When switching from an 8.0 g/10 min 12 wt% VA grade to ELVAX 670 at equal screw speed, melt pressure rises measurably; screw speed should be reduced while motor load and head pressure are monitored against barrel pressure ratings. A gear pump can stabilize die pressure and reduce surging, but it does not reduce the upstream pressure generated by the screw. Filtration screens should be opened progressively if pressure approaches the equipment limit. Thermal degradation can be monitored off-line by melt flow rate shift, yellowing index, or Fourier-transform infrared detection of acetate and carbonyl peak changes. In filled systems, the pH of quench water or the presence of acrid odor at the die can serve as an early warning of acetic acid release. Published data for this specific grade on production-scale flat-die and blown-film lines are limited; the acceptable throughput envelope must be established on the target line rather than extrapolated from small-scale rheology data.
EVA is not highly hygroscopic, and predrying is generally unnecessary below 50% relative humidity. If pellets are stored in unheated silos and moved into a warm processing area, condensation on cold pellet surfaces can produce surface moisture and film defects. In that case, a hopper dryer set at 60 °C for 4 h removes surface moisture without causing pellet blocking. Prolonged drying above 80 °C is not required and can increase the risk of pellet agglomeration. The resin should not be left in a heated extruder at 160 °C or above for extended shutdown periods; purge with LDPE before stops and between material changes.
Extrusion coating lines using ELVAX 670 are usually started with a higher-melt-index LDPE purge grade until the die flow is stable. The low melt index provides lower neck-in than an 8.0 g/10 min grade, but it also reduces draw-down and can limit maximum line speed before melt pressure or edge-bead control becomes limiting. Chill-roll surface temperature and air gap should be re-optimized because high melt viscosity reduces web wetting unless the melt curtain is sufficiently hot. Adhesion to aluminum foil and oriented polyester should be measured by peel testing in accordance with ASTM F904, because lower vinyl acetate content can reduce specific adhesion to polar substrates.
In coextruded sealant webs, ELVAX 670 functions as a high-melt-strength sealant or sub-sealant layer. The low melt index increases bubble stability in blown-film coextrusion and reduces neck-in during cast-film and extrusion-coating operations. Heat-seal initiation temperatures for 12 wt% VA EVA films are commonly near 90 °C when measured in accordance with ASTM F2029, but the actual value is a function of film thickness, seal-bar temperature profile, dwell time, and adjacent web thermal mass. Heat-seal strength is evaluated by ASTM F88 or ASTM F1921 on the finished package. The lower vinyl acetate content compared with 18–28 wt% grades shifts seal initiation upward but improves crystalline melting point and hot-tack stability, making the grade more resistant to seal distortion in moderately warm-fill applications. Dart impact toughness is typically lower than for 18 wt% or 28 wt% VA grades, and impact measurements should be repeated in accordance with ASTM D1709. Optical haze and clarity should be measured by ASTM D1003 because lower VA content can increase haze in thick films.
Compounding operations using ELVAX 670 as a high-viscosity carrier are torque-limited on twin-screw lines. On a co-rotating 25 mm extruder with 40:1 L/D, the resin can be fed as pellets or pre-blended with concentrate, but the specific energy input is higher than for a 2.5 g/10 min grade because of the higher melt viscosity. The high viscosity is advantageous for dispersing fillers and for transferring shear into agglomerates, but screw design must avoid excessive viscous heating. Barrel temperatures above 210 °C in mixing zones are not recommended because the local melt film temperature can exceed the 230 °C degradation threshold even when the bulk melt thermocouple reads lower. Dispersion quality in filled compounds should be assessed by filter pressure tests or by optical microscopy on pressed films; a baseline for unfilled ELVAX 670 should be recorded on the target line before filler addition. Published formulation data for this specific grade are limited, so candidate compounds require laboratory twin-screw evaluation before scale-up.
When substituting ELVAX 670 for Elvax 660 or for 18–28 wt% VA grades, melt-pressure and adhesion responses are not linear. Within the 12 wt% VA Elvax series, Elvax 650, Elvax 660, and ELVAX 670 form a melt-index ladder of 8.0, 2.5, and 0.35 g/10 min, respectively. Table 2 compares the nominal data. The lower melt index of ELVAX 670 increases melt strength and helps stabilize thick blown-film bubbles, but it also reduces maximum throughput at equal screw speed and increases the risk of excessive melt temperature in high-shear dies. When the replacement involves a higher-VA grade, the direction of change reverses: the 12 wt% VA resin has higher crystallinity, higher stiffness, lower room-temperature clarity, and a higher seal initiation temperature. Because the substitution is usually not drop-in, a structured design of experiments covering melt temperature, line speed, frost-line height, and die gap is recommended before commercial conversion.
| Grade | Vinyl acetate content | Melt flow rate at 190 °C / 2.16 kg | Density |
|---|---|---|---|
| Elvax 650 | 12 wt% | 8.0 g/10 min | 0.933 g/cm³ |
| Elvax 660 | 12 wt% | 2.5 g/10 min | 0.933 g/cm³ |
| ELVAX 670 | 12 wt% | 0.35 g/10 min | 0.933 g/cm³ |
Halogen-free flame-retardant compounds based on magnesium hydroxide or aluminum trihydrate use EVA carriers because of high filler tolerance and low acid evolution compared with halogenated systems. ELVAX 670 can be considered when the compound must have high melt strength and high filler-carrying capacity, but the viscosity increase must be managed through screw design and temperature profiling. Filler dispersion and fire performance are compound-specific; results should be generated in accordance with the intended end-use standards such as IEC 60332 or ASTM E1354 rather than inferred from the base resin properties alone.
For food-contact applications, ethylene-vinyl acetate copolymers are evaluated under FDA 21 CFR 177.1350 and EU Regulation (EU) No 10/2011 with substance-specific migration limits for vinyl acetate monomer. A supplier compliance statement is required for each lot, and the finished package must be tested under end-use conditions because migration is influenced by layer structure, temperature, and food simulant. Storage should avoid temperatures above 40 °C and direct ultraviolet exposure to limit molecular weight change and gel formation. Contact with strong oxidizing agents and with aromatic or chlorinated hydrocarbon solvents should be avoided because these materials can swell or degrade the copolymer.
