| HS Code | 780431 |
| Vinyl Acetate Content | 33% |
| Melt Flow Rate 190 C 2 16 Kg | 25 g/10 min |
| Density | 0.950 g/cm³ |
| Melting Point Dsc | 61°C |
| Vicat Softening Point | 43°C |
| Glass Transition Temperature | -50°C |
| Tensile Strength At Break | 5.5 MPa |
| Elongation At Break | 900% |
| Shore A Hardness | 70 |
| Shore D Hardness | 18 |
| Brittleness Temperature | -70°C |
| Refractive Index | 1.480 |
As an accredited Ateva 3325A Ethylene Vinyl Acetate Copolymer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Ateva 3325A Ethylene Vinyl Acetate Copolymer is supplied as pellets in 25 kg polyethylene bags, palletized and shrink-wrapped for safe transport. |
| Container Loading (20′ FCL) | Container Loading (20′ FCL): Palletize 25kg bags of Ateva 3325A EVA copolymer, secure loads, prevent shifting, ensure dry, ventilated conditions. |
| Shipping | Ateva 3325A EVA copolymer ships as solid pellets in moisture-barrier bags, gaylord boxes, or bulk hoppers. Ensure clean, dry transport to prevent contamination. Avoid excessive heat and impact; material is non-hazardous but dust may form. Store sealed in a cool environment until use. |
| Storage | Store Ateva 3325A EVA copolymer in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and moisture. Keep containers tightly sealed to prevent contamination and moisture pickup. Avoid excessive stacking to prevent pellet deformation. Use within recommended shelf life. |
| Shelf Life | Shelf life is typically two years when stored in a cool, dry place away from sunlight and moisture. |
In packaging hot-melt adhesive compounding, Ateva 3325A is introduced as the ethylene vinyl acetate backbone at 25–35 wt% of the finished adhesive formulation, with hydrogenated tackifier resins occupying 35–45 wt%, paraffin or Fischer-Tropsch waxes 15–25 wt%, and a hindered phenolic antioxidant at 0.5–1.0 wt%. The resin is melted in jacketed sigma-blade or change-can mixers at 160–180 °C under nitrogen blanketing to limit oxidative skin formation; viscosity is then adjusted by wax type and measured periodically by ASTM D3236-15 with a Brookfield Thermosel spindle 27. Production-scale behaviour in continuous hot-melt lines shows that melt temperatures above 200 °C generate acetic acid cleavage products, causing viscosity drift and carbonised deposits on slot-die coater lips and gear-pump bearings. Downstream application equipment includes roller coating, wide-slot nozzle coating, spiral spray applicators, and fibreised melt-blown heads for case sealing, bookbinding spine adhesion, paperboard tray assembly, and film-foil lamination. Food-contact terminal packages rely on FDA 21 CFR 175.105 for the adhesive, while the base resin falls under FDA 21 CFR 177.1350; in the European Union, the finished food-contact article is governed by Regulation (EU) No 10/2011 with an overall migration limit of 10 mg/dm², and raw-material traceability is maintained under REACH Regulation (EC) No 1907/2006.
In low-smoke zero-halogen cable jacketing, Ateva 3325A is compounded at 15–30 wt% of the polymer phase, where its nominal vinyl acetate content of 33 wt% assists wet-out and encapsulation of precipitated magnesium hydroxide and aluminium trihydrate fillers, while the base polyolefin fraction of linear low-density polyethylene or ethylene-octene copolymer supplies mechanical strength. Total metal hydrate filler loading in such systems typically reaches 55–65 wt%, with zinc borate at 5–10 wt%, antioxidant masterbatch at 0.5–1.0 phr, and a processing lubricant at 0.5–1.5 phr. Compounding is carried out on co-rotating twin-screw extruders with 36:1 to 44:1 L/D, polymer fed in the main hopper and fillers side-fed downstream to avoid excessive torque peaks; vacuum venting at −0.08 MPa removes moisture and volatiles. A critical processing boundary is that aluminium trihydrate begins releasing bound water above 185–200 °C, so barrel set temperatures must be trimmed to keep melt temperature below 200 °C, and filler moisture should be below 0.1% before side-feeding; wet filler produces porosity and surface roughness in the finished jacketing. In peroxide-cured halogen-free compounds, dicumyl peroxide added at 0.8–1.5 phr through a side feeder can be prematurely consumed by acidic decomposition products if the EVA phase is overheated; scorch safety at 140 °C is commonly evaluated by ISO 289-1:2018 Mooney viscometer testing, and production records indicate that excessive zinc stearate above 2 phr shortens scorch time by accelerating free-radical decomposition. Cable extrusion then proceeds through a crosshead die at 120–140 °C, with the compound used for low-voltage control cable sheaths, appliance wiring insulation, building wire jacketing, and mass-transit rolling-stock cables.
| Test property | Standard designation | Acceptance criterion |
|---|---|---|
| Halogen acid gas release | IEC 60754-1 | ≤0.5% HCl by mass |
| Effluent pH | IEC 60754-2 | ≥4.3 |
| Effluent conductivity | IEC 60754-2 | ≤10 µS/mm |
| Smoke density | IEC 61034-2 | light transmittance ≥60% |
| Limiting oxygen index | ISO 4589-2 | ≥30% O₂ |
In low-density crosslinked EVA foam, Ateva 3325A is charged as the base polymer at 100 parts per hundred resin, with azodicarbonamide blowing agent at 3.0–5.0 phr, dicumyl peroxide at 0.6–1.2 phr, zinc oxide at 1.5–3.0 phr, stearic acid at 0.5–1.0 phr, and calcium carbonate or talc filler at 10–15 phr. The high vinyl acetate content softens the resulting foam relative to lower-VA EVA grades, allowing Shore A hardness values to be reduced without the addition of liquid plasticisers, although published third-party data for this specific grade in foamed systems is limited; production qualification therefore typically relies on moving-die rheometer cure curves and batch sheet density measurement. Processing begins on a two-roll mill at 90–110 °C to disperse the blowing agent and peroxide, followed by sheeting, pre-cutting, and transfer into a compression moulding press heated to 155–165 °C under 14–18 MPa for 8–12 minutes; a subsequent cold press at 15–25 °C stabilises cell dimensions. Finished foam is tested for tensile properties under ASTM D638-14, hardness under ASTM D2240-15, and compression set under ASTM D395-18. Regulatory conformance covers REACH Regulation (EC) No 1907/2006, California Proposition 65 for consumer footwear components, and applicable finished-article requirements under Directive 2011/65/EU where electrical accessories are involved. Terminal product types include footwear midsoles, insoles, orthotic footbeds, soft foam sheet, anti-fatigue mats, and thermoformed foam packaging inserts.
Carbon black masterbatch production for polyolefin-based films and injection moulding compounds selects Ateva 3325A as carrier resin at 25–50 wt% of the concentrate, with pigment loading from 30–60 wt% and processing aids at 0.5–3 wt%; the 33 wt% vinyl acetate monomer content reduces crystalline melting plateaus and promotes pigment wetting at lower rotor speeds than non-polar carrier resins. On a production-scale 40:1 L/D co-rotating twin-screw extruder, carbon black is added through a side feeder after the polymer is melted, and the screw speed is limited to 300–400 rpm because shear heating above 210 °C accelerates vinyl acetate decomposition and acetaldehyde formation; vacuum venting at −0.08 MPa and downstream barrel cooling to 140–160 °C are used to control volatiles. Melt is passed through a 60–100 mesh screen pack and pelletised under a die-face hot-cut system. The resulting concentrates are used in black agricultural films, injection moulded automotive interior parts, pipe coatings, garbage bags, and extrusion coating layers. Food-contact packaging concentrates require the finished article to comply with FDA 21 CFR 177.1350 for ethylene-vinyl acetate copolymers and Regulation (EU) No 10/2011, with overall migration tested according to the food type and use condition; raw-material compliance is documented under REACH Regulation (EC) No 1907/2006.
In atactic polypropylene-modified bitumen waterproofing membranes, Ateva 3325A is added at 3–7 parts per 100 parts bitumen to improve cohesion, reduce melt viscosity at application temperature, and shift cold-bending flexibility toward lower service temperatures. The polymer is dispersed into oxidised or blown bitumen in a high-shear rotor-stator mixer at 180–190 °C for 60–90 minutes, after which the modified bitumen is calendered or extrusion-coated onto a polyester or glass-fibre carrier to a finished thickness of 3–5 mm; mineral granules, sand, or slate are pressed into the surface before cooling. The process boundary is governed by degradation: prolonged residence above 200 °C causes vinyl acetate cleavage and gel formation that blocks coating die lips and transfer pumps. Roofing membranes produced with this compound are qualified under EN 13707:2004+A2:2009 for flexible sheets for roof waterproofing, with cold flexibility determined by EN 1109 and low-temperature performance commonly specified at or below −10 °C; sampling and material verification follow ASTM D5147/D5147M-18. Terminal product types include torch-applied roofing membranes, self-adhesive cold-applied membranes, plaza deck waterproofing, below-grade tanking membranes, and bridge deck waterproofing systems.
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Supplied in pellet form for bulk handling and gravimetric feeding, Ateva 3325A Ethylene Vinyl Acetate Copolymer is a random copolymer containing a nominal vinyl acetate comonomer content of 33 wt%. The incorporation of vinyl acetate along the ethylene backbone disrupts crystallite formation, reduces the melting point below that of low-density polyethylene, and introduces polar ester functionality at the chain level. This compositional profile places the grade among high-vinyl-acetate EVA copolymers used where softness, low-temperature flexibility, and adhesion to polar substrates are specified. The resin is differentiated from lower-vinyl-acetate EVA grades by its lower crystalline fraction, lower modulus, and higher workable melt flow. Typical production-scale applications include hot-melt adhesive compounding, paraffin and microcrystalline wax modification, polymer modification in single- and twin-screw extrusion, and selected heat-sealable layer formulations where the sealing temperature must remain low. The product is not a drop-in for low-VA EVA film grades because the reduction in crystallinity changes tensile strength, melt tension, and blocking resistance in cast film processes.
The vinyl acetate content is controlled during copolymerization and is normally verified by Fourier-transform infrared spectroscopy or saponification/titration methods accepted in the industry. The melt flow rate is measured under the conditions specified in ISO 1133-1:2022 and ASTM D1238 using a 2.16 kg piston load at 190 °C. The grade designation 3325A corresponds to a nominal melt flow rate of 25 g/10 min, although lot-to-lot manufacturing windows and the exact reference temperature should be confirmed on the certificate of analysis. This flow class provides lower melt viscosity than extrusion-coating grades and higher melt viscosity than very high-flow hot-melt grades such as those above 100 g/10 min.
| Property | Test method | Published typical value |
|---|---|---|
| Vinyl acetate comonomer content | ASTM D5594 | 33 wt% |
| Melt flow rate at 190 °C, 2.16 kg | ISO 1133-1:2022 / ASTM D1238 | 25 g/10 min |
| Density at 23 °C | ISO 1183-1 | 0.95 g/cm³ |
| Melting point by DSC | ISO 11357-3 | 62–64 °C |
The primary specification for this grade is the combination of 33 wt% vinyl acetate and nominal 25 g/10 min melt flow rate. The density value is a function of the vinyl acetate fraction; it is higher than low-density polyethylene and lower than polyvinyl acetate homopolymer. Differential scanning calorimetry of EVA with this comonomer level typically shows broad melting endotherms because the random comonomer sequence prevents formation of long ethylene crystallites. The low melting point allows adhesive and wax compounders to operate at lower melt temperatures than those required for 18 wt% or 28 wt% vinyl acetate EVA grades.
Mechanical property values are not single-point constants for this material; they depend on thermal history, cooling rate, and the degree of compatibility with tackifiers or waxes. Published tensile and hardness data should therefore be treated as values obtained under standardized specimen preparation, not as guarantees for finished compounds. The copolymer is normally characterized for molecular weight distribution indirectly through melt flow rate and for comonomer content through FTIR, because these two parameters dominate processing and adhesion performance. The base resin is generally intended for industrial and adhesive applications. For food-contact use, compliance must be established under 21 CFR 177.1350 for ethylene-vinyl acetate copolymers or the applicable EU 10/2011 migration limits; the appropriate regulatory documentation and end-use limitations should be confirmed before use. No statement of universal food-contact suitability is made solely from the resin composition.
On high-shear hot-melt compounding lines, the measured melt temperature often exceeds the barrel set temperature by 10–30 °C due to viscous dissipation. For Ateva 3325A, the upper practical melt-temperature limit should be maintained below 200 °C, and shorter residence times are preferred because the vinyl acetate ester is susceptible to thermal deacetylation. Acetic acid elimination is the dominant degradation pathway; it is autocatalytic once initiated, and it creates acidic vapor that can corrode carbon steel equipment and alter tackifier compatibility. For this reason, vented extruder configurations, 316L stainless steel contact surfaces, and acetic acid-resistant seals are standard where prolonged compounding runs are performed. Pre-drying at 50–60 °C for 4–6 h is advised when the pellet has been exposed to ambient relative humidity above 60%, because moisture entrapment can generate voids in extruded adhesive profiles and depress measured bonding continuity.
Twin-screw compounding with this grade is usually carried out in corotating intermeshing extruders with length-to-diameter ratios between 25:1 and 40:1. The resin melts early along the screw, so the first heating zones may be set to 90–120 °C, with later zones at 130–160 °C and the die below 170 °C. When the compound contains high-softening-point rosin ester tackifiers, a distributive screw configuration with low kneading-block intensity is preferred because the EVA phase has low melt viscosity and may bypass high-viscosity tackifier domains if the shear stress is too low. Conversely, excessive specific mechanical energy input promotes localized heating and ester cleavage. Processors therefore control screw speed and feed rate as paired variables rather than optimizing them independently.
Batch-to-batch variation in this grade is most visible in adhesive draw-down behavior and melt viscosity. A shift in melt flow rate of ±2 g/10 min within the manufacturing window may require barrel temperature adjustment of approximately 5–10 °C to hold the same apparent viscosity. In-line rheometers or capillary viscometers using ASTM D3835 provide more useful release data than a single melt flow rate value because the polymer is shear-thinning; a single-point test at 190 °C cannot capture the viscosity response of the formulation across the 100–1000 s⁻¹ shear range encountered in slot-die coating.
In adhesive formulation, the practical difference between Ateva 3325A and a 28 wt% vinyl acetate EVA grade is not limited to the comonomer weight fraction. The increased polarity of the 33 wt% grade shifts solubility behavior toward polar tackifiers, lowers melt temperature, and reduces the elastic character of the melt. This creates faster wetting of paper and board substrates but also reduces cohesive strength at elevated service temperatures. When compared with an 18 wt% vinyl acetate EVA, Ateva 3325A can lose roughly 15–20 Shore A points and shows a melting point depression of approximately 20 °C; such differences are measurable using ISO 868 and ISO 11357-3.
| Property | 18 wt% vinyl acetate EVA | 28 wt% vinyl acetate EVA | Ateva 3325A, 33 wt% |
|---|---|---|---|
| DSC melting point, ISO 11357-3 | 84–88 °C | 70–74 °C | 62–64 °C |
| Shore A hardness, ISO 868 | 90–94 | 75–84 | 65–75 |
| Polar substrate adhesion | Moderate | Good | High |
| Melt flow class | Similar or lower depending on grade | Similar or lower depending on grade | 25 g/10 min |
The flow rate also differentiates the grade from lower-melt-index EVA copolymers of similar vinyl acetate content. A low-melt-index analogue at 6–10 g/10 min may be selected for blown film or heavy-duty profiles because it retains melt strength and bubble stability. The 25 g/10 min flow of Ateva 3325A is more suited to adhesive stringing, thin coating, penetration into fibrous substrates, and blending with low-viscosity waxes. The trade-off is reduced melt tension; in any process requiring vertical draw or unsupported web transfer, the line speed and melt temperature must be adjusted to prevent draw resonance or web sagging.
Replacement of a 28 wt% vinyl acetate EVA with Ateva 3325A in a polymer modification or hot-melt formulation should not be treated as a simple one-for-one substitution. The higher comonomer content lowers the softening point and increases polarity, which alters phase morphology in blends with nonpolar polyolefins and waxes. The processing window narrows slightly because the melt temperature observed under identical screw conditions will be lower, but the maximum safe temperature remains constrained by vinyl acetate degradation. Barrel set temperatures may need to be reduced by 5–15 °C to maintain equivalent stock temperature, particularly on long extruders where residence time is already high.
In hot-melt adhesive formulas, replacing 28 wt% vinyl acetate EVA with this grade can improve low-temperature flexibility and adhesion to polar substrates, but it may require reformulation of wax and tackifier levels. The higher vinyl acetate content increases compatibility with rosin ester tackifiers and decreases compatibility with high-molecular-weight paraffin waxes; a formulation that was clear at 28 wt% vinyl acetate may become translucent or show wax exudation at 33 wt%. Compatibility should be tested by hot melt cloud point, visual inspection after 48 h at 25 °C, or differential scanning calorimetry of the cooled blend. The test protocol should include reproducibility across at least three batches because technical waxes vary in n-paraffin and iso-paraffin distribution.
For hot-melt adhesive formulations, a practical starting point is to pre-blend all solid components at 60–80 °C before raising the temperature to final mixing. The EVA pellets soften before the tackifier melts; this can produce a heterogeneous melt if the tackifier is added too late or if the mixer has poor axial flight clearance. Single-screw extruders with intensive mixing sections are less effective than twin-screw or sigma-blade mixers for this class because the low-melt-viscosity EVA may act as a lubricant and reduce shear input to the tackifier.
In wax-based compositions, the copolymer functions as both viscosity modifier and flexibilizer. At typical addition levels of 5–15 wt% in paraffin wax, the low-temperature cracking tendency of the wax is reduced, but the change in melt viscosity is nonlinear with concentration. Rotational viscometry at 100 °C is required to quantify the effect because wax crystallization can mask the viscosity response when the blend is measured just above the cloud point.
Published data for the exact replacement ratio in every compound matrix is limited. A conservative approach is to begin at a 10% lower addition level by weight and evaluate the compound for heat resistance, tensile properties, and melt flow stability before running full production.
In hot-melt adhesive systems, Ateva 3325A is typically combined with tackifier resins at ratios that balance wet adhesion and cohesive strength. The polymer contributes cohesive integrity and film forming, while tackifiers lower melt viscosity and promote specific adhesion. Rosin ester tackifiers with softening points between 80 °C and 105 °C are widely used; hydrocarbon tackifiers may require compatibility screening because aliphatic resins can phase-separate from the polar EVA domains. Hot-melt viscosity is measured by rotational viscometry under ASTM D3236 at 121 °C or 177 °C, with viscosity values reported in millipascal-seconds or centipoise.
Adhesive performance is assessed through standardized peel and tack methods rather than ambient handling alone. For packaging and converting laminates, ASTM D1876 T-peel is used to quantify peel strength; ASTM D6195 loop tack can be used for pressure-sensitive or low-tack formulations, although the product is not a pressure-sensitive adhesive by itself. When coated on kraft paper or linerboard using a slot-die line, the open time is controlled by melt temperature, line speed, and substrate temperature. Production-scale experience shows that poorly controlled substrate moisture can retard heat transfer and create uneven adhesive transfer; the substrate surface temperature should be recorded at the nip rather than inferred from oven set points.
The upper service temperature limitation of this grade is the main operational boundary in structural or semi-structural bonding. Because the polymer softens at approximately 62–64 °C, adhesives formulated solely with this grade cannot be expected to retain significant shear strength at continuous service temperatures above 60 °C. Resistance to creep under load at 40–50 °C remains formulation-dependent and should be verified by ASTM D2293 or similar creep test rather than by softening point alone. Additives that generate strong acidity or alkalinity should be avoided, as they can accelerate ester cleavage and reduce melt stability.
