| HS Code | 732483 |
| Va Content | ≥40% |
| Density | 0.96 - 0.98 g/cm³ |
| Melt Flow Rate | 2 - 20 g/10min |
| Tensile Strength | 10 - 20 MPa |
| Elongation At Break | 800 - 1200% |
| Hardness | 60 - 80 Shore A |
| Flexural Modulus | 20 - 50 MPa |
| Melting Point | 60 - 70 °C |
| Glass Transition Temperature | -30 to -40 °C |
| Vicat Softening Temperature | 40 - 50 °C |
| Brittleness Temperature | ≤ -70 °C |
| Volume Resistivity | 10^13 - 10^15 Ω·cm |
As an accredited EVAFLEX Very High VA Series EVA Copolymer Resin,≥40% VA,Elastomer Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | EVAFLEX Very High VA Series EVA Copolymer Resin is supplied as pellets in 25 kg net, polyethylene-lined paper bags, palletized for transport. |
| Container Loading (20′ FCL) | 20′ FCL loading of EVAFLEX Very High VA EVA resin: palletized 25kg bags, heat-sealed, containerized securely for safe transport. |
| Shipping | Ship as non-hazardous solid EVA resin pellets in sealed moisture-proof bags or containers. Avoid excessive heat, direct sunlight, and mechanical damage. Keep dry and well-ventilated during transit. No special dangerous goods requirements; standard freight handling applies. Ensure stable stacking and protection from compression to prevent deformation. |
| Storage | Store in a cool, dry, well-ventilated area, away from direct sunlight, heat, and ignition sources. Keep containers tightly sealed to prevent moisture absorption and contamination. Avoid prolonged exposure to temperatures above 40°C to prevent pellet sticking or degradation. Maintain good housekeeping to minimize dust accumulation. |
| Shelf Life | Stable for at least 12 months when stored unopened in a cool, dry area, avoiding direct sunlight. |
EVAFLEX Very High VA Series EVA Copolymer Resin, with vinyl acetate content at or above 40 wt%, is incorporated as an amorphous elastomer phase in halogen-free flame-retardant cable compounds. On a production-scale twin-screw extruder with L/D 44:1–52:1, the resin is pre-dried at 55–60°C until residual moisture falls below 0.03 wt%, because absorbed water generates surface roughness and screw-slip disturbances. Barrel zones are maintained at 130–170°C; the die head is held at 150–160°C. A dual thermal ceiling exists: aluminum trihydrate begins endothermic water release near 200°C, and high-VA EVA starts deacetylation with acetic acid liberation within the same range. This makes melt temperatures above 200°C a critical process boundary, producing gas bubbles, die deposit, and corrosion on uncoated screw elements. The high-polarity VA comonomer permits total filler loadings of 150–200 phr as ATH or MDH, with high-VA EVA representing 30–60 wt% of the polymer phase when blended with LLDPE or POE. Filler is side-fed downstream of the melt zone through a twin-screw side feeder to reduce barrel abrasion; 80–120-mesh screen packs collect char. Sheathing is applied on high-speed catenary lines at 50–400 m/min depending on conductor cross-section. Compliance is checked against IEC 60754-1:2011, IEC 60754-2:2011, IEC 61034-2:2019, IEC 60332-1-2:2004, EN 50399:2022, and IEC 60811-401:2012; the finished products include low-voltage power cable sheathing, railway tunnel cable jackets, and building control cable insulation.
| Standard designation | Measured parameter | Relevance to HFFR cable compound |
|---|---|---|
| IEC 60754-1:2011 | Halogen acid gas content | Screening for halogen-free classification |
| IEC 60754-2:2011 | pH and conductivity of combustion effluent | Acid gas corrosivity |
| IEC 61034-2:2019 | Smoke density | Visible smoke obscuration |
| IEC 60332-1-2:2004 | Vertical flame propagation | Single cable flammability |
| EN 50399:2022 | Heat release and flame spread | Multi-cable fire performance |
| IEC 60811-401:2012 | Tensile retention after ageing | Thermal endurance of sheathing |
When vinyl acetate content moves above 40 wt%, polyethylene crystallinity is suppressed to the point where the resin behaves as a soft elastomer rather than a semi-crystalline thermoplastics modifier. In hot melt adhesive formulation, this changes the adhesion mechanism: polar substrate wetting dominates, and low-temperature bond flexibility improves, but cohesive strength and heat resistance decline unless the formulation is rebalanced with a higher softening point tackifier. Production formulations for case and carton closing contain 25–40 wt% high-VA EVA, 30–45 wt% rosin ester or aliphatic hydrocarbon tackifier, 10–20 wt% Fischer-Tropsch wax, and 0.5–1.0 wt% hindered phenolic antioxidant. The resin is melted in a jacketed, nitrogen-covered batch mixer at 150–170°C and transferred through a heated manifold to gear-pump-driven applicators at 150–180°C. Spray, slot-die, and roller coating methods are selected by substrate and line configuration. Because deacetylation accelerates above 190°C, residence time in the hot reservoir is restricted, and viscosity drift or gel formation indicates acetic acid generation from the VA comonomer. T-peel adhesion on corona-treated PET and coated board is measured per ASTM D1876; melt flow rate is measured per ISO 1133-1:2022. Food-contact packaging adhesives are regulated under FDA 21 CFR 175.105, while EU product declarations follow REACH and Regulation (EC) No 1935/2004 where applicable. End products include carton sealing, bookbinding, profile wrapping lamination, and filter frame bonding. Resin stored at relative humidity above 60% is dried at 50°C for 4–6 h to prevent pump cavitation and foamed adhesive beads.
In calendered flexible PVC waterproofing membrane, high-VA EVA elastomer grade is introduced at 5–20 phr as a non-migrating polymeric flexibilizer that partially replaces low-molecular-weight liquid plasticizers. The VA comonomer improves low-temperature fold resistance and reduces Shore A hardness without the surface exudation associated with dioctyl phthalate systems. The PVC dry blend is mixed in a hot/cold mixer to 110–120°C, then melt-compounded in a Banbury mixer or counter-rotating twin-screw extruder at 160–180°C. Calendering is performed with roll temperatures of 170–190°C and an embossing gap matched to the target thickness. Tensile strength and elongation are tested according to ASTM D638-14 and ISO 527-2; dimensional stability, fold resistance, and seam strength are evaluated under EN 13956. The finished products include single-ply roofing membranes, tunnel linings, and containment liners. Addition above 20 phr may reduce tensile strength and increase film blocking; published data for this specific configuration is limited, so production-scale trials are required before replacing conventional plasticizer packages. A heat stabilizer package is mandatory during compounding because hydrogen chloride from PVC degradation can catalyze further deacetylation of the EVA and darken the melt.
Polymer-modified bitumen for waterproofing and bridge deck surfacing often relies on styrenic block copolymers, but high-VA EVA with vinyl acetate content at or above 40 wt% is introduced where elastic recovery and low-temperature flexibility are required without full SBS substitution. Addition levels are 3–7 wt% of total bitumen compound. The bitumen is preheated to 160–170°C, then the resin is fed into a high-shear mixer operating at 3,000–6,000 rpm for 2–4 h; an inert gas blanket limits oxidation and volatile loss. The mixing temperature is held below 190°C to prevent acetic acid evolution from the VA comonomer. Storage stability is evaluated by measuring the softening point difference between upper and lower thirds after 72 h at 180°C; product specifications are structured around EN 13399 and EN 14023. Elastic recovery and penetration are measured per ASTM D6084 and EN 1426. Finished products include torch-applied waterproofing membranes and bridge deck paving compounds. Compatibility with the bitumen maltene/asphaltene balance varies by refinery lot, and published data for this specific configuration is limited; storage stability must be verified against each bitumen batch before transfer to production.
In crosslinked polyolefin foam production, high-VA EVA with VA content at or above 40 wt% is used as a soft, high-elongation component in EVA/LDPE blends. A starting blend ratio of 20–40 wt% high-VA EVA to 60–80 wt% lower-VA EVA or LDPE reduces Shore A hardness and increases resilience, but excessive high-VA EVA raises tack and lowers melt strength during expansion. Compounding is performed in an internal mixer at 105–115°C, followed by a two-roll mill at 95–105°C, where dicumyl peroxide at 0.6–1.0 phr and azodicarbonamide blowing agent at 1.5–3.0 phr are dispersed. The sheet is cured in a multi-opening hydraulic press at 150–170°C and 100–200 kgf/cm² for 10–15 min. Cure kinetics are monitored with an oscillating disc rheometer per ISO 6502; finished foam properties are evaluated under ASTM D3575 and ISO 7214, and compression set is determined per ISO 1856. End products include footwear midsoles, anti-fatigue mats, and thermal insulation tubes. Because high-VA EVA can release acetic acid at elevated process temperatures, the cure time above 170°C is kept to a minimum to avoid interference with peroxide decomposition and cell collapse.
High-VA EVA copolymer with vinyl acetate content at or above 40 wt% is processed into PVC-free flexible medical film and tubing where phthalate plasticizer absence and low modulus are required. In monolayer cast film, the resin is used as the sole polymer; in coextruded structures, it constitutes 30–60 wt% of the total layer thickness with a polyolefin tie layer. The resin is dried at 50–60°C to below 0.05 wt% moisture before extrusion. Cast film extrusion is performed at melt temperatures of 150–170°C; blown film extrusion uses a low blow-up ratio and chilled air to prevent tack-induced blocking. Tubing extrusion is run on a single-screw extruder with L/D 24:1–30:1 and vacuum calibration. Biological evaluation follows ISO 10993-5 and ISO 10993-10; USP Class VI and FDA 21 CFR 177.1350 apply where cited in device submissions. Tensile properties are measured per ASTM D638-14, hardness per ISO 868. End products include drainage bags, medical packaging film, and cushioning layers in wound care devices. Because the high VA content creates a tackier surface, anti-blocking agents are incorporated at 0.5–2.0 wt% to prevent roll blocking; radiation sterilization may increase gel formation and must be validated per ISO 11137.
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EVAFLEX Very High VA Series EVA Copolymer Resin, designated as an elastomer grade with vinyl acetate content ≥40 wt%, is a random ethylene-vinyl acetate copolymer supplied as cylindrical pellets. Within this grade family, the vinyl acetate comonomer weight fraction spans approximately 40–50 wt%, while the melt mass-flow rate is adjusted across family members from 2 g/10 min to 25 g/10 min at 190 °C under a 2.16 kg load according to ISO 1133-1:2022. Density increases with vinyl acetate content to 0.97–0.99 g/cm³ when determined by ISO 1183-1:2019. The principal structural difference from conventional EVA is the strong suppression of polyethylene crystallinity; differential scanning calorimetry under ISO 11357-3:2018 records a melting endotherm of 45–65 °C instead of the 70–90 °C typical of EVA with 18–28 wt% VA. The resulting material is a permanently flexible, low-hardness, tacky elastomer that remains melt-processable on standard polyolefin compounding lines. The series is used in impact modification of polyamide and polyester compounds, high-polarity hot-melt adhesive formulations, melt-blending of compatibilized polymer alloys, and flexible compound bases requiring high elongation and low hardness. Because the series is a grade family, lot-specific melt mass-flow rate, vinyl acetate content, Shore A hardness, and density must be obtained from the manufacturer’s certificate of analysis before compounding or molding. Published data for this specific configuration is limited; lot-specific values control process setup.
At 18–28 wt% vinyl acetate, EVA retains crystalline ethylene sequences that produce measurable melting endotherms between 70 °C and 90 °C, Shore A hardness values from 80 A to 95 A, and tensile strengths commonly in the 10–30 MPa range. The present series, with vinyl acetate at ≥40 wt%, contains acetate side groups at a frequency sufficient to interrupt long ethylene runs, lowering residual crystallinity to <10% in the higher-VA grades and shifting the melting peak to 45–65 °C. Hardness falls to 55–75 A after 15 s on 6 mm plaques under ISO 7619-1:2010; tensile strength measured on type 2 dumb-bells in accordance with ISO 37:2017 is usually 5–15 MPa, and elongation at break commonly reaches 700–1000%. The acetate dipole increases cohesive energy density and improves adhesion to polar substrates such as aluminium, polyester film, glass, and polyurethane foam; however, the same polarity raises moisture affinity and water-vapour transmission. Rheologically, high-VA EVA shows stronger shear-thinning and greater melt-temperature sensitivity than low-VA extrusion grades, as measured by complex viscosity under ISO 6721-10:2021. Storage modulus decreases steeply above 120 °C, so screw-speed and barrel-profile changes produce larger melt-pressure fluctuations than they would in a semicrystalline EVA.
For specification verification, vinyl acetate content is determined by infrared spectroscopy following ASTM D5594-17 or ISO 8985:2022; films for analysis are compression molded below 200 °C to prevent deacetylation. Melt mass-flow rate is characterized under ISO 1133-1:2022 at 190 °C and 2.16 kg, with moisture content at the die maintained below 0.05 wt% to prevent bubble formation and apparent melt-flow drift. Shore A hardness is measured after 15 s on plaques conditioned at 23 °C and 50% relative humidity per ISO 7619-1:2010. Density is reported by ISO 1183-1:2019; a gradient column or gas pycnometer is preferred because pellet surface voids from pelletization can distort immersion methods. Tensile properties are determined on type 2 dumb-bells by ISO 37:2017 at 500 mm/min, but soft grades may require non-contact video strain measurement because of large extension. The following table summarizes typical property differences against conventional EVA; the figures are representative literature values rather than single-point specifications.
| Parameter | Conventional EVA 18–28 wt% VA | EVAFLEX Very High VA Series ≥40 wt% VA |
|---|---|---|
| Vinyl acetate content | 18–28 wt% | 40–50 wt% depending on grade |
| Melting peak by DSC, ISO 11357-3:2018 | 70–90 °C | 45–65 °C |
| Shore A hardness, ISO 7619-1:2010 | 80–95 A | 55–75 A |
| Tensile strength, ISO 37:2017 | 10–30 MPa | 5–15 MPa |
| Elongation at break, ISO 37:2017 | 300–700% depending on VA and grade | 700–1000% |
| Density, ISO 1183-1:2019 | 0.93–0.95 g/cm³ | 0.97–0.99 g/cm³ |
| Adhesion to polar substrates | moderate, primer often required | higher, acetate dipoles increase surface energy |
Compounding of the EVAFLEX Very High VA Series on a co-rotating twin-screw extruder with a 40:1 L/D segmented barrel typically employs a flat or moderately decreasing temperature profile, with feed-zone temperature set at 120–140 °C, mixing-zone temperature at 160–180 °C, and die temperature at 170–190 °C. The material is shear- and temperature-sensitive; localized melt temperatures in high-shear kneading blocks should remain below 210 °C because deacetylation accelerates above 230 °C, releasing acetic acid and creating viscosity drift and pellet discoloration. Screw configurations for high-VA EVA benefit from fewer neutral kneading blocks and reverse elements than are used for low-VA EVA, because excessive viscous heating pushes the melt into the deacetylation regime. Pellets should be fed into the extruder at a controlled rate consistent with the screw intake capacity; feed-throat temperatures above 140 °C can soften the pellets prematurely and cause bridging or feed-blockage. On production-scale lines, the most frequently observed failure mode is melt-pressure fluctuation at the die caused by feed-zone softening or by moisture-loaded pellets. When ambient relative humidity exceeds 60%, pre-drying in a desiccant dryer at 60–70 °C for 4–6 h with a dew point of −40 °C is used to maintain pellet moisture below 0.05 wt%. If filler or additive masterbatches are added downstream of the melting zone, the injection point should be located after the primary melting section to avoid unnecessarily increasing melt viscosity.
Impact modification of engineering thermoplastics with the Very High VA Series is typically evaluated at addition levels of 5–30 wt%. In polyamide and polyester compounding, domain formation depends on the melt-viscosity ratio between matrix and modifier; when the EVA melt mass-flow rate is below 10 g/10 min, an interfacial viscosity ratio below 3:1 is preferred to achieve sub-micrometre rubber droplets in twin-screw mixing. Low-temperature notched Izod impact energy, measured under ISO 180:2019 method A, often improves with high-VA EVA modification, but the effect is matrix-specific and can be reduced by moisture-induced hydrolysis of ester linkages if processing temperatures exceed 240 °C or if the matrix contains free amine end groups. In polyamide systems, addition of hindered phenol-phosphite stabilizer packages at 0.2–0.5 wt% is common because residence times above 180 °C can induce chain extension and gel formation. For hot-melt adhesive formulations, the high vinyl acetate content improves wetting of aluminium, polyester film, polyethylene terephthalate, and polyurethane foam; open time and softening point are controlled by the melt-index grade and the wax/resin ratio, not by the EVA base resin alone. For flexible compounds, the elastomer grade can replace a portion of plasticizer or thermoplastic elastomer, but its compression set resistance is limited above 80 °C compared with sulfur-cured EPDM.
Ambient storage in sealed, moisture-protected packaging is required for the EVAFLEX Very High VA Series. After opening, exposure to relative humidity above 60% increases surface moisture and can produce pellet agglomeration during drying. Because the acetate content is susceptible to hydrolysis at elevated temperature, re-drying should not exceed 70 °C for more than 8 h; higher temperatures or longer residence times increase surface tack and can fuse pellets in a conventional hot-air dryer. The resin should not be combined with amine-based additives that accelerate ester degradation; contact with strong oxidizing agents and copper-based stabilizer packages should be evaluated by retention trials before production. Regulatory status for ethylene-vinyl acetate copolymers under FDA 21 CFR 177.1350 and European Commission Regulation (EU) No 10/2011 applies only to specific food-contact grades and conditions of use, not automatically to every elastomer grade in the series. RoHS Directive 2011/65/EU compliance is typically supported by supplier declarations for lead, mercury, cadmium, hexavalent chromium, and brominated flame retardants; REACH SVHC content above 0.1 wt% should be confirmed through the material safety data sheet and certificate of analysis. When the product is used in medical or electrical-insulation applications, ISO 10993-5 and IEC 60674-3-1 may require additional end-application testing; the base resin should not be assumed compliant without formulation-specific validation.
| Regulatory/Standard | Applicability | Condition |
|---|---|---|
| FDA 21 CFR 177.1350 | Food-contact EVA | Grade-specific, only where supplier states compliance |
| EU Regulation (EU) No 10/2011 | Plastic food-contact materials | Condition-of-use and migration testing required |
| RoHS Directive 2011/65/EU | Electrical/electronic equipment | Supplier declaration for Pb, Hg, Cd, Cr6+, PBB, PBDE |
| REACH SVHC | EU market | Confirm 0.1 wt% threshold via SDS/CoA |
| ISO 10993-5 | Medical device cytotoxicity | End-article testing required |
| IEC 60674-3-1 | Electrical insulation film | Formulation-specific validation required |
Compared with metallocene ethylene-octene polyolefin elastomers, the Very High VA Series offers higher polarity and better adhesion to polar films, but lower thermal-oxidative stability and higher moisture sensitivity. At equal Shore A hardness, high-VA EVA shows lower compression set resistance than sulfur-cured EPDM under ISO 815-1:2019, limiting long-term sealing above 80 °C. It is melt-processable without a post-cure cycle; standard single-screw extruders with a 3-zone screw can be used for profile or sheet lines provided the melt temperature is held below 200 °C. Production-scale experience indicates that higher temperatures cause visible acetic acid odour and pellet discoloration, while extended residence time in a heated screw barrel increases surface tack and can lead to material build-up on the die lip.
