| HS Code | 581773 |
| Productname | Ethylene-Vinyl Acetate Copolymer EVA 1803C |
| Vinylacetatecontent | 18% |
| Meltflowrate | 3.0 g/10 min (190°C/2.16 kg) |
| Density | 0.940 g/cm3 |
| Meltingpoint | 85°C |
| Vicatsofteningpoint | 58°C |
| Tensilestrength | ≥16 MPa |
| Elongationatbreak | ≥650% |
| Shoreahardness | 88 |
| Shoredhardness | 35 |
| Brittletemperature | ≤-70°C |
| Volumeresistivity | ≥1×10^14 Ω·cm |
| Dielectricconstant | 2.5 at 1 kHz |
| Thermaldecompositiontemperature | ≥200°C |
As an accredited Ethylene-Vinyl Acetate Copolymer EVA 1803C factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied in 25 kg net moisture-resistant bags, palletized and labeled for safe industrial handling. |
| Container Loading (20′ FCL) | Container Loading (20′ FCL): EVA 1803C in 25 kg bags, palletized and loaded into a 20′ FCL, secured and sealed for export. |
| Shipping | Ship Ethylene-Vinyl Acetate Copolymer EVA 1803C in original sealed, moisture-resistant packaging. Store and transport in a dry, cool, ventilated area away from heat, direct sunlight, and ignition sources. Avoid contamination. Normally not classified as dangerous goods for transport. |
| Storage | Store Ethylene-Vinyl Acetate Copolymer EVA 1803C in a cool, dry, well-ventilated warehouse away from direct sunlight, heat, flames, and oxidizing agents. Keep bags/containers closed to prevent moisture pickup and contamination; avoid dust generation and static buildup. Maintain stable temperature, use first-in-first-out, and follow SDS/local regulations. Do not stack excessively; protect packages from damage and punctures. Ensure good housekeeping and segregation from incompatible materials. |
| Shelf Life | Typically 24 months when stored in original unopened packaging in a cool, dry, well-ventilated area, away from direct sunlight and moisture. |
EVA 1803C with a nominal vinyl acetate content of 18 wt% and a melt mass-flow rate of 3.0 g/10 min determined by ISO 1133-1:2022 at 190°C/2.16 kg is compounded into peroxide-cured, chemically foamed footwear midsole formulations. The resin is charged into a 50–120 L internal mixer with dicumyl peroxide at 0.8–1.2 phr, azodicarbonamide at 2.0–3.5 phr, zinc oxide at 1.0–2.0 phr, stearic acid at 0.5 phr, calcium carbonate at 10–20 phr, and a blowing-agent decomposition aid. The mixer jacket is held at 110–125°C. The batch is dropped at 115–120°C to prevent premature azodicarbonamide decomposition. The material is then milled on a two-roll mill at 85–95°C for 4–6 min and sheeted at 5.0 mm thickness. Pelletizing uses an underwater strand die with water temperature below 40°C. For injection moulding, barrel temperatures are 160–175°C, mould temperatures are 165–175°C, and cure times range from 300 s to 420 s for a 10 mm midsole wall. The foam reaches a density of 0.15–0.25 g/cm³ by ISO 845. Hardness values fall between 48 and 58 Asker C. Rebound by ASTM D2632 is 45–55%. Compression set per ASTM D395 at 23°C/24 h is 25–35%. The main processing bottleneck is the narrow zone between azodicarbonamide decomposition onset near 195°C and peroxide decomposition demand. If the melt front exceeds 180°C before mould filling is complete, gas bubbles collapse and surface sink marks appear. Demould remains difficult above 55°C part-surface temperature.
| Azodicarbonamide loading | Foam density | Asker C hardness | Compression set after 24 h |
| 2.0 phr | 0.24 g/cm³ | 56 | 30% |
| 2.5 phr | 0.21 g/cm³ | 52 | 29% |
| 3.0 phr | 0.18 g/cm³ | 50 | 27% |
| 3.5 phr | 0.15 g/cm³ | 48 | 26% |
Mould design for EVA 1803C foam requires controlled gas venting. Vent channels are cut to 0.03–0.05 mm because gas by-products include nitrogen, carbon monoxide, and carbon dioxide. The mould parting line is maintained parallel to the fill direction. Gate thickness is 1.5–2.0 mm, and gate land length is 2.0–3.0 mm. Runner systems are balanced for filling. The pressure drop across the runner should not exceed 30 MPa. If pressure drop is too high, peroxide cures prematurely. Foam density distribution across a 260 mm midsole should not vary by more than 0.02 g/cm³. Batch-to-batch variation in melt flow rate above ±0.5 g/10 min changes shot size and density by 8–10%. Incoming resin lots are therefore checked by ISO 1133-1. Reclaimed foam flash can be added at 5–10 wt% without severe property loss. Beyond 15 wt%, elongation at break falls below 200% and the midsole may crack during repeated flexing.
In continuous sheet extrusion, EVA 1803C is fed with a chemical blowing-agent masterbatch based on azodicarbonamide or 4,4′-oxybis(benzenesulfonylhydrazide). The extruder is a single-screw design with a 44:1 L/D ratio and a barrier screw. Barrel zones are set to 120°C, 150°C, 165°C, 175°C, 180°C, 175°C, 165°C from hopper to die. The die temperature is held 5–10°C below the maximum melt temperature to preserve cell integrity. Screw speed is restricted to 40–80 rpm. Higher shear generates viscous heat that can advance decomposition inside the screw channel and create gas pockets. The flex-lip die has a land length of 10–15 mm and a lip gap of 0.8–1.2 mm. Melt pressure must remain above 8 MPa. A pressure drop below 6 MPa before the die exit causes pre-foaming and surface roughness. The resulting sheet is passed over a chilled three-roll stack at 25–35°C. Sheet density is 0.12–0.20 g/cm³ measured by ISO 845. Machine-direction tensile strength by ISO 527-3 is 1.5–2.5 MPa. Tear resistance by ASTM D624 die C is 12–18 N/mm. Water absorption by ISO 62 after 24 h is 0.6–1.2%. This sheet is converted into expansion joint fillers, gasket tapes, thermal insulation, and protective packaging. The most common batch failure is surface roughness caused by moisture above 0.1%. Pre-drying at 60–70°C for 2–4 h is required when ambient relative humidity exceeds 60%.
EVA 1803C is used as a base resin in halogen-free flame-retardant cable jackets where UL 94 vertical burning and IEC 60332 flame-spread requirements apply. The resin is compounded with aluminum trihydrate at 120–160 phr, magnesium dihydrate at 20–40 phr, a maleic anhydride-grafted polyolefin coupling agent at 5–10 phr, and a processing aid at 2–5 phr. The twin-screw extruder is a co-rotating 40–48:1 L/D machine with atmospheric and vacuum vents. Barrel temperatures from feed to die are set between 120°C and 170°C. Melt temperatures are kept below 185°C because aluminum trihydrate releases water of hydration above approximately 190°C. A side feeder at the fourth barrel introduces the mineral filler after the resin is molten. Vacuum venting at −0.08 MPa removes surface moisture. Filler moisture above 0.3% causes porosity in the extruded jacket. The melt pressure before the screen pack reaches 20–25 MPa at 150 phr aluminum trihydrate. Screw speed is reduced to 200–250 rpm to limit shear heating. The resulting compound has tensile strength of 9.0–11.0 MPa by ISO 527-2, elongation at break of 180–220%, and limiting oxygen index of 31–33% by ISO 4589-2. The main technical limitation is the filler-loading threshold above 165 phr. At that point melt viscosity increases sharply, Charpy notched impact strength by ISO 179-1 drops below 20 kJ/m², and extrusion surface finish deteriorates.
| Property | Standard | Requirement | Typical result |
| Tensile strength | ISO 527-2 | ≥ 9.0 MPa | 10.5 MPa |
| Elongation at break | ISO 527-2 | ≥ 150% | 190% |
| Limiting oxygen index | ISO 4589-2 | ≥ 30% O₂ | 32% |
| Vertical burning | UL 94 | V-0 at 3.0 mm | Pass |
| Hot set | IEC 60811-507 | Elongation ≤ 175% at 200°C/15 min/0.2 MPa | Pass |
Thermal ageing in cable applications is evaluated by IEC 60216 or product-specific cable standards. The compound must retain at least 75% of original elongation after 168 h at 100°C. The selection of EVA 1803C over higher-VA grades reduces the quantity of smoke suppressant needed but narrows filler acceptance. Reactivity with amine-based additives is a known incompatibility. Primary or secondary amines can discolour the compound and destabilise the peroxide cure. Compliance documents must include REACH SVHC declarations and RoHS 2011/65/EU Annex II substance limits for lead and cadmium.
Injection moulding of technical flexible components uses the 3.0 g/10 min melt flow rate of EVA 1803C to fill thin-wall cavities without excessive injection pressure. The melt temperature is adjusted from 180°C to 210°C. The mould temperature is controlled at 20–40°C. Injection pressure is 70–100 MPa. Clamp force is calculated at 3–5 kN/cm² of projected area. Parts include automotive pedal covers, brake-lever sleeves, grommets, cable bushings, and handle grips. Hardness after moulding is 88–92 Shore A by ISO 868. Flexural modulus by ISO 178 is 45–60 MPa. The low crystallinity at 18 wt% vinyl acetate produces elastic recovery after repeated flexing, but it also lowers heat deflection. The material should not be used at continuous service temperatures above 70°C. Weld-line tensile strength is 60–70% of the non-weld value by ISO 527-2. Mould shrinkage is 1.0–1.5% parallel to flow and 0.8–1.3% transverse. Pre-drying at 60°C for 2 h is required if the resin has been exposed to humidity above 60%. Self-adhesion is sufficient for overmoulding onto polyolefin substrates. The formulation must not contain free hydrazine-based blowing agents if the finished part is to meet FDA 21 CFR 177.1350 for ethylene-vinyl acetate copolymers.
EVA 1803C is compounded into colour concentrates for polyolefin film and injection-moulding applications. The carrier phase uses the low crystallinity of EVA to wet organic pigments and carbon black. Pigment loadings range from 20 wt% to 40 wt%. The resin is first fluxed in a 50–100 L internal mixer at 110–125°C. Pigments are added after the resin melts to avoid agglomeration. The batch is then extruded through a single-screw feeder into a pelletizing die with a 100/200/100 mesh screen pack. Filter pressure value is maintained below 0.5 MPa/min. Higher filter pressure indicates undispersed pigment particles above 20 µm. Letdown ratios in LLDPE are 2–5 phr. The use of EVA 1803C as carrier reduces melt temperature during film extrusion by 5–8°C compared with LDPE carrier. This protects heat-sensitive pigments. However, addition above 10% into a high-pressure LDPE film can reduce film haze and seal performance. Do not combine the carrier with calcium stearate above 2 phr. Plate-out on the die lip becomes visible after 4 h of continuous extrusion.
In coextruded cast and blown-film structures, EVA 1803C is used in the sealant layer where lower seal initiation compared with LDPE is required but high hot tack is not critical. The resin is processed on a three-layer blown-film line with a die gap of 1.5–2.0 mm and a blow-up ratio of 2.0–2.5. Melt temperature at the die is 200–220°C. The sealant-layer thickness is 10–20 µm within a total film of 40–80 µm. Heat-seal initiation is approximately 85–95°C at a seal pressure of 0.3 MPa and 0.5 s dwell. Seal strength reaches 8–12 N/15 mm by ASTM F88/F88M. The 18 wt% vinyl acetate content reduces the hot-tack plateau compared with EVA grades containing 28 wt% VA. Thus the material is not selected for high-speed vertical form-fill-seal machines above 80 bags/min. Published data for this specific grade in coextruded sealant films is limited. Converter trials use a sealant-layer percentage of 15–25%. The main incompatibility is with low-density polyethylene grades containing high levels of slip agent. Migration of the slip agent raises the seal-initiation temperature by 3–5°C. This grade is also not suitable for retortable pouch structures because steam sterilization at 121°C causes seal creep and delamination.
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Ethylene-vinyl acetate copolymer EVA 1803C is a medium-viscosity grade with nominal vinyl acetate comonomer content of 18 wt%. Melt mass-flow rate is typically 3.0 g/10 min at 190 °C under a 2.16 kg load when tested to ASTM D1238-23 or ISO 1133-1:2022, and solid-state density is typically 0.940 g/cm³ when determined under ASTM D1505-18 or ISO 1183-1:2019. The suffix C in the grade designation does not carry a uniform cross-producer definition; it is treated as a controlled conformance or additive-package variant unless the lot certificate of analysis states otherwise. The material is supplied as pellets for injection molding, profile extrusion, and chemically blown foam processes. Within the EVA family, the 18 wt% vinyl acetate content places the grade between lower-VA polyethylene-segment resins and higher-VA elastomeric grades, reducing crystallinity and broadening low-temperature flexibility relative to LDPE while retaining sufficient melt strength for foam expansion.
Processors use EVA 1803C in applications requiring a balance of toughness, flexibility, and foaming behavior. Incoming resin should be inspected for melt flow rate, density, and vinyl acetate content per lot. Since the grade is not hygroscopic, drying is generally unnecessary; if pellets have been stored at relative humidity above 60%, surface moisture should be removed at 60 °C to 70 °C for 2 h to 4 h before processing. Drying above 80 °C for extended periods is not recommended because pellet agglomeration may occur near the softening point.
Publicly available technical datasheets for EVA 1803C typically list a restricted set of grade-defining values. The following nominal values are used for incoming inspection and initial process setup; lot-specific values should be obtained from the certificate of analysis because comonomer distribution, additive concentration, and batch-to-batch rheological variance may shift within the producer’s specification window.
| Property | Test method | Unit | Nominal value |
|---|---|---|---|
| Vinyl acetate content | internal FTIR or qNMR | wt% | 18 |
| Melt mass-flow rate | ASTM D1238-23 / ISO 1133-1:2022 | g/10 min | 3.0 |
| Density | ASTM D1505-18 / ISO 1183-1:2019 | g/cm³ | 0.940 |
| Melt flow rate ratio or molecular weight distribution | not uniformly specified | — | consult COA |
Because EVA 1803C is a copolymer, single-point melt index is insufficient to predict molecular architecture. A complete rheological fingerprint requires capillary rheometry or oscillatory shear. Tensile and flexural data are not uniformly published for this specific grade; comparative mechanical characterization should follow ASTM D638-22 with Type IV specimens at 50 mm/min and ASTM D790-17 for flexural modulus, with specimens conditioned at 23 °C ± 2 °C and 50% ± 5% relative humidity.
Incorporation of 18 wt% vinyl acetate along the ethylene backbone disrupts crystallizable polyethylene sequences. The effect is quantified by differential scanning calorimetry under ASTM D3418-21: the melting endotherm shifts to lower temperatures relative to LDPE, and the heat of fusion decreases. For analogous 18 wt% vinyl acetate copolymers, melting peak temperatures are commonly reported between 80 °C and 85 °C, although exact values depend on comonomer sequence distribution, cooling rate, and annealing history. Low-temperature flexibility can be characterized by dynamic mechanical analysis in torsion using ASTM D5279-21; the glass transition region for this comonomer level generally appears between −30 °C and −20 °C. The broadened low-temperature service window is a key selection criterion in footwear midsole compounds and flexible extruded profiles, where stiffening at subambient exposure is undesirable.
Compared with LDPE, the higher vinyl acetate content also imparts polarity to the polymer chain. This improves adhesion to polar substrates in melt lamination but also increases equilibrium moisture uptake and reduces resistance to nonpolar solvents. Solvent resistance is not inferred from resin category alone; it requires immersion testing per ISO 175:2010 or ASTM D543-21 under specific media, temperature, and exposure duration.
On production-scale single-screw foam sheet lines, barrel temperature profiles are generally set from 110 °C to 130 °C in the feed zone, rising to 150 °C to 190 °C in the compression and metering zones. Head pressure is held below 20 MPa to avoid premature gas evolution and melt surging. Screw geometries with L/D 30:1 and a barrier mixing section are preferred for uniform temperature distribution. In injection molding, a reciprocating screw with compression ratio 2.0:1 to 2.8:1 and a check-ring tip is used; melt temperature at the nozzle typically ranges from 170 °C to 210 °C, while mold temperature is maintained at 20 °C to 40 °C. Clamp force requirements scale with projected area; for thin-wall molds, filling pressure may reach 80 MPa to 120 MPa, although specific values should be confirmed by mold-flow simulation because EVA 1803C exhibits pronounced shear-thinning behavior.
Typical injection-molded failures include short shots in thin sections when melt temperature is below 170 °C and sink marks when mold packing pressure is released too early. EVA 1803C solidifies through a semicrystalline transition, so mold cooling time depends on part thickness; for a 2 mm wall, cooling may be 8 s to 15 s with mold at 25 °C. Weld-line strength is sensitive to melt temperature and injection speed; tensile strength at the weld line can be measured with a double-gated tensile specimen under ASTM D638-22, and retained strength is typically lower than that of the base resin. Published data for this specific configuration is limited; production validation should include short-shot studies and pressure-drop monitoring.
The melt flow rate of 3.0 g/10 min is a low-shear index and does not fully describe extrusion behavior. Capillary rheometry at shear rates between 100 s⁻¹ and 1,000 s⁻¹ and at 190 °C provides pressure-drop data for die design. EVA 1803C displays pseudoplastic behavior; apparent viscosity decreases as shear rate increases. This reduces screw torque in twin-screw compounding but also lowers die pressure stability when extruder speed changes. On a 90 mm single-screw extruder with L/D 30:1, melt pressure fluctuations should be controlled within ±0.5 MPa to limit output variation and gauge deviation in sheet. The melt is thermally sensitive above 210 °C; prolonged residence time should be minimized because vinyl acetate groups can undergo acetic acid elimination, reducing viscosity and generating surface defects. The additive package can shift this threshold; production trials should establish the maximum allowable melt residence time.
EVA copolymers degrade through deacetylation at elevated temperature. Vinyl acetate units adjacent to ethylene sequences can eliminate acetic acid through a cyclic transition state; the rate accelerates above 210 °C and is influenced by residence time, shear rate, and the presence of acid scavengers. Thermogravimetric analysis under nitrogen at 10 °C/min according to ISO 11358-1:2022 typically shows onset of mass loss above 310 °C for similar EVA resins, but lower-temperature processing can still release acetic acid if melt residence time is excessive. Equipment exposed to EVA should use corrosion-resistant screw metallurgy or full hard chrome plating, and purge with LDPE before shutdown. In hot-runner systems, acetic acid byproducts can cause gate deposit and plate-out; mold surface treatments such as electroless nickel or titanium nitride are used to reduce adhesion.
Molecular weight degradation during processing can be monitored by melt flow rate shift. If melt flow rate increases by more than 10% from virgin pellets after one heat history, process temperature or residence time should be reduced. Acetic acid evolution can be detected with pH-sensitive probes at the vent; sustained vent vapor pH below 4.0 indicates autocatalytic degradation. Addition of acid scavengers such as calcium stearate or hydrotalcite at 0.1 phr to 0.5 phr may be used where acetic acid generation is problematic, but additive selection must not interfere with adhesion or surface finish.
In chemically blown foam, the decomposition temperature of the blowing agent must overlap with the melt state of EVA 1803C without exceeding degradation. Azodicarbonamide decomposes near 190 °C to 210 °C; its exothermic decomposition may require cooling in the later barrel zones. A typical loading is 1.5 phr to 3.0 phr for footwear foam, but the exact loading must be determined by free-rise foam density tests and final part density requirements. Sodium bicarbonate-based systems release gas at lower onset temperatures near 140 °C to 160 °C and are used for lower-density sheet. Apparent density of the expanded foam is measured according to ISO 845:2009; cell structure is assessed by optical or scanning electron microscopy cross-sections. Crosslinked foam formulations may incorporate dicumyl peroxide; the cure kinetics interact with blowing agent decomposition, so temperature profiling must separate peroxide decomposition and gas evolution to prevent cell rupture. If gel content is used as a quality parameter, extraction is commonly performed in boiling xylene for 12 h; the target gel fraction depends on the end-use application and must be established by the processor.
Scrap integration is limited by the vinyl acetate content and the presence of blowing agent residues. Reprocessing of crosslinked foam scrap is not possible as a melt; uncrosslinked EVA 1803C scrap can be reground and re-introduced at controlled levels if thermal history and contamination are monitored.
Relative to EVA grades with vinyl acetate content of 9 wt% to 12 wt%, EVA 1803C has lower crystallinity, lower tensile modulus, and greater low-temperature flexibility; however, it also exhibits higher gas permeability and lower heat resistance. Grades with 25 wt% to 28 wt% vinyl acetate are softer and show stronger adhesion to polar substrates, but their Vicat softening temperatures are lower and their pellet surfaces may become tacky during warm storage. The 3.0 g/10 min melt flow index differentiates EVA 1803C from lower-flow grades used in blown film and higher-flow grades used in hot-melt compounds. Published data for the exact performance envelope of EVA 1803C is limited; grade comparison should be confirmed by comparative testing under identical specimen preparation and test protocols. The suffix C may indicate a controlled additive or food-contact conformance; where application-specific migration limits apply, the manufacturer’s regulatory statement should be requested.
Regulatory compliance should not be assumed from generic EVA chemistry. When the material is specified for food contact, the producer should confirm compliance to 21 CFR 177.1350 for ethylene-vinyl acetate copolymers, including extractives limitations under simulated use conditions. For heavy metal restrictions, test the lot against RoHS 2011/65/EU recast annex II limits, typically 100 mg/kg cadmium and 1,000 mg/kg lead. REACH registration obligations are substance-level and do not guarantee article compliance. If the grade is intended for medical packaging, ISO 10993-5 and ISO 10993-10 screening may be required, but the raw resin is not inherently USP Class VI certified unless documented by the supplier.
