| HS Code | 465772 |
| Product Name | ELVAX 3155 Ethylene Vinyl Acetate Copolymer |
| Chemical Family | Ethylene Vinyl Acetate (EVA) Copolymer |
| Vinyl Acetate Content | 15% |
| Melt Flow Index | 6 g/10 min (190°C / 2.16 kg) |
| Density | 0.935 g/cm³ |
| Melting Point | 80°C |
| Crystallization Point | 60°C |
| Tensile Strength At Break | 15 MPa |
| Elongation At Break | 750% |
| Flexural Modulus | 65 MPa |
| Shore D Hardness | 38 |
| Brittleness Temperature | -80°C |
| Refractive Index | 1.495 |
As an accredited ELVAX 3155 Ethylene Vinyl Acetate Copolymer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | ELVAX 3155 ethylene vinyl acetate copolymer is supplied as free-flowing pellets in 25 kg multi-wall paper bags. |
| Container Loading (20′ FCL) | 20′ FCL loaded with ELVAX 3155 in bags/palletized, secured, ventilated, dry container; weight optimized, safe handling ensured. |
| Shipping | ELVAX 3155 is a non-hazardous ethylene vinyl acetate copolymer supplied as solid pellets. Ship in sealed, moisture-resistant bags or containers to prevent clumping. Store away from direct heat, ignition sources, and strong oxidizers. No special transport classification required; handle with standard industrial hygiene to minimize dust exposure. |
| Storage | Store ELVAX 3155 in its original, unopened packaging in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and UV radiation. Keep containers tightly sealed to prevent moisture pickup and contamination. Avoid exposure to strong oxidizers. Under recommended conditions, this ethylene vinyl acetate copolymer should remain usable for at least two years. |
| Shelf Life | Shelf life is typically two years from shipment if stored in original, unopened packaging under cool, dry conditions. |
ELVAX 3155 has a vinyl acetate content of 15% by weight and a melt mass-flow rate of 55 g/10 min under ISO 1133-1:2022. In case-and-carton sealing operations running at 40 to 80 cycles/min, the resin is compounded at 20 to 40 parts per hundred resin with hydrogenated rosin ester or aromatic-modified C5 tackifier and a Fischer-Tropsch wax. The vinyl acetate content restricts specific adhesion to untreated polyolefin substrates, so corona treatment of HDPE surfaces to 38–44 dyn/cm is specified before hot melt application; however, the same comonomer level reduces acetic acid generation compared with 28% VA grades and stabilizes viscosity during extended pot life. Formulators avoid residual strong acid species in tackifying resins because catalytic deacetylation accelerates viscosity creep and slot-die corrosion. In a corotating twin-screw extruder with an L/D ratio of 40:1 and barrel zones set from 120°C to 160°C, the resin is melt-mixed with tackifier and wax under vacuum devolatilization to remove moisture and low-molecular-weight volatiles. A melt pump and 150–200 mesh screen pack are required to protect the slot-die lips from char particles. Application viscosity is measured by ASTM D3236 at 180°C using a Brookfield Thermosel; formulations containing 30 phr ELVAX 3155 typically remain within 600–1,200 mPa·s, a range that avoids stringing yet maintains sufficient wet-out on kraft board. Open time is governed by the crystallization exotherm of the wax phase and is held between 2 and 8 s on high-speed compression sections; overdosing EVA above 40 phr produces cold creep and fiber-tearing failures. The final adhesive is tested by ASTM D1876 T-peel on kraft-to-corrugated coupons and by ASTM D3163 lap shear on PETG carton board. Regulatory compliance for food packaging closures follows FDA 21 CFR 175.105 as an indirect food additive. Terminal products include RSC case sealing, tray forming, and bookbinding side gluing.
Paraffin wax used in corrugated board and paper cup coatings is modified with 2 to 10 wt% ELVAX 3155 to raise low-shear melt viscosity and depress the brittle point of the wax layer. The wax is charged to a jacketed blending kettle and heated to 110–130°C under a low-shear impeller rotating at 30–60 rpm; the EVA pellets are added after the paraffin reaches 100°C to avoid localized overheating near the vessel wall. Oil content in the base paraffin must remain below 30 wt% because higher oil fractions reduce the EVA network density and cause phase separation after 24 h of static melt storage. Curtain coating is performed at 120–140°C on a corrugator after the board surface reaches 20–35°C. Curtain height is maintained at 150–250 mm; if the height exceeds 300 mm, turbulent air entrainment creates streak defects. The EVA-paraffin film is metered to a dry pickup of 15–30 g/m²; below 15 g/m² pinholes and edge wicking failures are observed by TAPPI T 454 turpentine resistance testing. A production bottleneck occurs when the paraffin contains more than 5 wt% microcrystalline wax, because the resulting melt viscosity exceeds 80 mPa·s at 120°C and the curtain splits at the die edges. Thermal stabilizers are added at 0.1–0.3 wt% to control color development during 8 h production runs. Compliance for paper and paperboard in contact with aqueous and fatty foods is established under FDA 21 CFR 176.170 and 176.180. Terminal materials are waxed corrugated cases for wet produce, paper cups, and laminated overwrap.
| Downstream application | Regulatory instrument | Test designation |
|---|---|---|
| Hot melt packaging adhesive | FDA 21 CFR 175.105 | ASTM D3236, ASTM D1876 |
| Paraffin wax paper coating | FDA 21 CFR 176.170, 176.180 | TAPPI T 454, ASTM E96 |
| Solvent-borne lamination adhesive | FDA 21 CFR 175.105 | ASTM D903, ASTM D1876 |
| Pigment masterbatch carrier | EU 10/2011, FDA 21 CFR 177.1350 | ISO 1133-1:2022, EN 13900-5 |
| Bituminous waterproofing membrane | EN 13707, ASTM D5147 | ASTM D36, ASTM D5, EN 1109 |
| Coextruded sealant layer | FDA 21 CFR 177.1350 | ASTM F88, ASTM D3418 |
ELVAX 3155 is dissolved in a toluene-methyl ethyl ketone blend at a solids content of 15–30 wt%; the low molecular weight of the resin allows a solution viscosity of 200–800 mPa·s at 25°C when measured with a Brookfield RVT viscometer at 20 rpm. The solution is coated by gravure cylinder onto polyester, BOPP, or aluminum foil at 60–120 lines/cm, followed by a forced-air drying oven with zone temperatures from 60°C to 90°C and a residence time of 10–20 s. Lamination nip temperature is set at 70–85°C with a pressure of 3–5 bar to activate the EVA surface without causing film shrinkage. The dried adhesive layer is tested by ASTM D903 on flexible film laminates and by ASTM D1876 T-peel after 24 h conditioning at 23°C and 50% relative humidity. Residual solvent content in food-contact laminates is measured by headspace gas chromatography and kept below 5 mg/m²; the adhesive formulation is assigned to FDA 21 CFR 175.105 for indirect food contact, while direct food contact layers must independently meet FDA 21 CFR 177.1350. A process conflict in this application is the slow evaporation of MEK from deep gravure cells; if line speed exceeds 150 m/min without a secondary infrared tunnel, residual solvent causes delamination and off-odor in finished pouches. Terminal products are dry-food pouches, foil-laminated dessert lids, and stand-up pouch plies.
Compounding pigment masterbatches for blown polyethylene film uses ELVAX 3155 as a carrier because the 55 g/10 min melt mass-flow rate under ISO 1133-1:2022 permits pigment loadings of 30 to 50 wt% without exceeding the torque limit of a 44:1 L/D corotating twin-screw extruder. Carbon black, phthalocyanine blue, or titanium dioxide is fed through a side stuffer after the carrier resin has been melted in barrels set from 130°C to 160°C; screw speed is held between 300 and 500 rpm to generate high-shear dispersion while keeping melt temperature below 180°C. A screen pack sequence of 60/120/200 mesh removes agglomerates larger than 74 µm. Pre-drying at 70°C for 4 h is specified when ambient relative humidity exceeds 60%, because water absorbed on the resin pellets causes bubble defects and filter pressure rise. Dispersion quality is assessed by an EN 13900-5 filter pressure value on a laboratory single-screw extruder; a pressure rise below 0.2 bar/min is typically required for 25 µm blown film. The final masterbatch is let down at 4–10 wt% in LDPE or LLDPE. For food packaging films, the final article is evaluated under EU 10/2011 and the EVA fraction is covered under FDA 21 CFR 177.1350. Terminal products include black agricultural mulch film, opaque packaging film, and injection-molded crates.
Oxidized bitumen for torch-applied waterproofing membranes is modified with 5 to 15 wt% ELVAX 3155 in a high-shear rotor-stator mixer at 170–190°C under a nitrogen blanket to limit oxidative hardening. The EVA is added after the bitumen reaches 150°C; mixing continues for 30–60 min until a homogeneous phase is confirmed by a ASTM D36 ring-and-ball softening point of 100–130°C and a ASTM D5 penetration value between 20 and 50 dmm at 25°C. The modified bitumen is calendered onto a polyester or glass-fiber reinforcement at 140–160°C with a line speed of 10–20 m/min to form a 3–5 mm membrane. Cold bending resistance is tested by EN 1109; low-temperature flexibility improves when EVA content is above 8 wt%, but viscosity rises steeply above 12 wt%, limiting calender throughput. For base bitumens with more than 30% asphaltene content, phase inversion is observed as a dull surface bloom; published data for this specific configuration is limited, so pilot blending is required. The finished membrane must meet EN 13707 for flexible sheets for waterproofing and ASTM D5147 where North American specifications apply. Terminal products include torch-applied roofing membranes, foundation waterproofing sheets, and below-grade tanking.
In three-layer blown film lines, ELVAX 3155 is dry-blended with LDPE at 10–30 wt% in the sealant layer to reduce heat-seal initiation temperature from approximately 105°C to 85°C. The melt is processed through a 1.5 mm die gap with a blow-up ratio of 2.0:1 to 2.5:1 and a melt temperature of 180–195°C; screen packs are 40/80 mesh to avoid high backpressure. Antiblocking agent is included at 0.1–0.3 wt% to prevent blocking on film reels. Pre-drying is necessary when pellets have been exposed to relative humidity above 60%; otherwise haze in the sealant layer increases. Seal strength is evaluated by ASTM F88 on 25.4 mm strips after jaw sealing at 120°C and 0.28 MPa for 0.5 s. The sealant layer complies with FDA 21 CFR 177.1350 for food contact; total migration is measured under EU 10/2011 if the final package is sold in the European Union. A production bottleneck is melt stagnation in the outer spiral mandrel when changing from LDPE to EVA-containing structures; purge times are extended to 15–20 min to eliminate gel specks. Terminal products include lamination-grade sealant webs, fast-seal packaging films, and overwrap for hygiene products.
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ELVAX 3155 is an ethylene vinyl acetate copolymer with a nominal vinyl acetate content of 15 wt% and a melt index of 55 g/10 min when tested at 190 °C under a 2.16 kg load according to ASTM D1238-20 or ISO 1133-1:2022. The reported density is 0.940 g/cm³ by ASTM D792-20. The resin is supplied as pellets and occupies the high-flow, medium-polarity segment of the EVA copolymer range. Its vinyl acetate level is high enough to improve adhesion to porous and polar substrates, yet low enough to maintain compatibility with paraffin wax and aliphatic tackifiers. The melt index indicates a lower average molecular weight than extrusion-grade EVA resins of the same comonomer content, which makes ELVAX 3155 particularly suitable for hot-melt adhesive, wax-modification, sealant, and masterbatch processes where low melt viscosity is the controlling variable.
| Property | Typical value | Test method or basis |
|---|---|---|
| Vinyl acetate comonomer | 15 wt% | Manufacturer FTIR method |
| Melt index | 55 g/10 min | ASTM D1238-20, 190 °C, 2.16 kg |
| Density | 0.940 g/cm³ | ASTM D792-20 |
| Recommended hot-melt processing range | 140–180 °C | Equipment-dependent processing guideline |
| Physical form | Pellets | Visual inspection |
Because the resin is a random copolymer, the 15 wt% vinyl acetate content disrupts polyethylene crystallinity enough to reduce stiffness, increase impact tolerance, and provide polar interaction sites on the polymer chain. It remains more aliphatic than 25–28 wt% vinyl acetate copolymers, which is the structural reason for its broader wax compatibility and lower equilibrium moisture uptake. The melt index value of 55 g/10 min is a nominal midpoint rather than a lot-specific guarantee; processors should request certificate-of-analysis data for melt index and density when qualifying a production line. In addition, melt index is an inverse molecular-weight indicator, not a complete rheological specification. It does not by itself define viscosity under high shear, melt strength during drawdown, or creep resistance in a finished bond.
A melt index of 55 g/10 min corresponds to lower average molecular weight than lower-melt-index grades such as ELVAX 550 at 8 g/10 min or ELVAX 560 at 2.5 g/10 min. In hot-melt adhesive operations, this reduces zero-shear viscosity and pressure drop through heated hoses, gear pumps, and slot dies. Industrial capillary-rheology data for EVA resins with melt-index values near 55 g/10 min commonly place low-shear melt viscosity in the range of 200–500 Pa·s at 190 °C; the exact value depends on comonomer distribution, molecular weight distribution, and antioxidant package. The resin is shear thinning, so viscosity decreases further under coating and spraying shear rates. This permits faster application speeds on corrugated case-sealing and carton-closing lines, and it allows some formulations to run at hose and nozzle temperatures closer to 150 °C rather than 180 °C, reducing thermal degradation risk.
On production-scale packaging lines, the lower melt viscosity can also produce a narrower processing window for fibre formation in spiral-spray application. If melt temperature is too high or wax content is too low, fibre breakup becomes excessive and adhesive misting increases. If temperature is too low, substrate wetting falls and bond level becomes dependent on compression time. Published data for specific Nordson or ITW Dynatec melter configurations with this exact grade is limited; converters should establish gravimetric add-on and fibre pattern at the intended line speed rather than transferring machine settings from another EVA grade. Batch-to-batch variation in melt index can shift pump output and spray pattern, so lot-specific melt index data should be recorded during production qualification.
Blending ELVAX 3155 into paraffin wax systems is controlled mainly by the 15 wt% vinyl acetate fraction. Fully refined paraffin wax accepts this grade more readily than 25–28 wt% vinyl acetate copolymers because the lower polar fraction reduces the enthalpy of mixing with aliphatic wax. Addition levels of 2–10 wt% are common for improving flexibility, reducing blocking, and raising adhesion to paperboard in curtain-coating and impregnation applications. Below 2 wt%, the modification effect on low-temperature flexibility is often too small to justify the additional mixing step. Above 10 wt%, blend viscosity can exceed the range suitable for curtain coating, especially at melt temperatures below 120 °C. Blending is typically performed in agitated melt vessels at 120–150 °C for 30–60 min. Extended residence beyond 60 min can produce acetate odour and darkening, particularly if the vessel has dead zones or insufficient agitation. The same addition rate may require adjustment when using microcrystalline wax or synthetic Fischer-Tropsch wax because those waxes have higher melt viscosity and different crystalline structure than fully refined paraffin.
In packaging adhesives, the high melt index of ELVAX 3155 reduces shear adhesion failure temperature compared with a lower-melt-index grade of the same vinyl acetate content. This difference is most evident in case-sealing or tray-forming operations exposed to warehouse temperatures above 45 °C or to direct sunlight on trucks. Under ASTM D4498, SAFT values for hot-melt adhesives based on 55 g/10 min EVA are typically lower than equivalent formulations based on 8 g/10 min or 2.5 g/10 min grades. Specific values are formulation-dependent and cannot be predicted from melt index alone. Tensile energy to break measured by ASTM D638 is also lower for the 55 g/10 min grade than for lower-melt-index grades at the same vinyl acetate level, making the material more appropriate for low-load, temporary, or high-speed assembly bonds than for structural or long-duration load-bearing joints.
Compared with ELVAX 410, an 18 wt% vinyl acetate resin with a 500 g/10 min melt index, ELVAX 3155 provides higher cohesive strength and lower odour, but higher application viscosity. Compared with ELVAX 550, a 15 wt% vinyl acetate resin with an 8 g/10 min melt index, ELVAX 3155 provides lower application viscosity and faster wetting on kraft paper but lower creep resistance and lower SAFT. Compared with 25–28 wt% vinyl acetate copolymers, ELVAX 3155 has lower adhesion to polar films and aluminium, as measured by ASTM D1876 T-peel or ASTM D903 peel testing. The lower vinyl acetate level also reduces solubility in ketone and ester solvents, which can be an advantage for solvent resistance but a limitation when developing solvent-borne adhesives requiring high polarity. Published data for this specific grade on metallised polyester or coated corrugated board is limited; production-substrate adhesion testing is required because surface treatment, paper sizing, and silicone release residues control practical bond values.
| Product | Vinyl acetate | Melt index | Principal processing difference versus ELVAX 3155 |
|---|---|---|---|
| ELVAX 3155 | 15 wt% | 55 g/10 min | Baseline high-flow, medium-polarity grade |
| ELVAX 550 | 15 wt% | 8 g/10 min | Lower melt viscosity, higher cohesive strength, higher SAFT, lower line speed capability |
| ELVAX 560 | 15 wt% | 2.5 g/10 min | Extrusion-grade melt strength, unsuitable for most hot-melt systems without high pressure |
| ELVAX 410 | 18 wt% | 500 g/10 min | Ultra-high flow, lower cohesive strength, lower application temperature potential |
| ELVAX 260 | 28 wt% | 6 g/10 min | Higher polarity and polar-substrate adhesion, lower paraffin compatibility |
ELVAX 3155 is not limited to hot-melt adhesives; it is also compounded as a carrier resin for colour and additive masterbatches, as a flexibility modifier for sealants, and as a processing aid in some wire and cable compounds. In twin-screw extrusion, its lower molecular weight reduces motor load at a given throughput. Barrel profiles from 100 °C to 160 °C with extruder L/D ratios between 30:1 and 48:1 are typical. The feed throat should remain below 50 °C because pellet surface softening can cause bridging and feed fluctuations. Pellets exposed to relative humidity above 60% should be dried at 70–80 °C for 2–4 h before extrusion to prevent surface defects in tapes, profiles, or strand pelletising. In masterbatch formulations with more than 30 wt% pigment or mineral filler, the low melt viscosity can improve wetting and dispersion but may also reduce pressure stability in the die; a gear pump or back-pressure valve is often used to stabilise output.
Thermal degradation is the main operational boundary. EVA resins can undergo deacetylation at sustained melt temperatures above 200 °C, releasing acetic acid and causing discoloration, viscosity drift, gel formation, and corrosion of downstream equipment. Residence time should be kept below 30 min at 180 °C and below 15 min for highly filled masterbatches. Dead spots in melt lines, unheated flanges, and poorly purged hot-melt hoses can accelerate char formation. Combinations with strongly alkaline or amine-based additives can catalyse deacetylation and should be avoided unless the stabiliser package is specifically redesigned. Sealant and adhesive end uses requiring continuous service above 60 °C should be reformulated with a lower-melt-index EVA or a crosslinked system to avoid creep. These boundaries are derived from general EVA processing practice and should be confirmed with lot-specific thermal stability data under ASTM D3418 differential scanning calorimetry or thermogravimetric analysis before final qualification.
