ELEVATE EM518AA Ethylene Vinyl Acetate Copolymer

During compression molding of cross-linked olefin foam, EM518AA is compounded with azodicarbonamide and dicumyl peroxide in an internal mixer. A process-validated starting formulation is 100 phr EM518AA, 2.5–4.5 phr azodicarbonamide, 0.6–1.0 phr dicumyl peroxide, 0.8–1.5 phr zinc oxide, and 0.5–1.0 phr zinc stearate. The dicumyl peroxide decomposition half-life at 160 °C is sufficiently short to initiate cross-linking, while azodicarbonamide gas yield becomes incomplete below 170 °C unless activated by zinc oxide; this creates a narrow processing window in which premature cross-linking raises roll nip torque and late gas evolution produces internal blow holes. The batch is discharged from the internal mixer at 105–115 °C, sheeted on a two-roll mill at 80–90 °C, and then expanded in a multi-daylight compression press at 150–165 °C under 10–15 MPa for 8–12 min, followed by cooling under pressure to stabilise cell dimensions. Density after expansion is tested to ISO 845:2006, compression set to ISO 815-1:2019, and foam cell structure to ASTM D3575-20; REACH Regulation (EC) No 1907/2006 Annex XVII and RoHS Directive 2011/65/EU Annex II restrict plasticisers and heavy metals in finished consumer goods. Terminal product types include running shoe midsoles, insoles, protective knee pads, anti-fatigue matting, and archery arm guards.

How Is EM518AA Incorporated into Cast Film Sealant Webs and Extrusion Lamination Layers?

For cast film extrusion and extrusion lamination, EM518AA is dry-blended with a low-density polyethylene carrier at 15–35 wt% depending on the required seal initiation temperature. The blend lowers seal initiation to 105–125 °C when measured on a heat-seal tensile machine according to ASTM F88/F88M-21; below 15 wt% hot tack may be insufficient, while above 35 wt% blocking and reel-to-reel friction increase on the chill roll. The compounded pellets are fed into a single-screw extruder with 30:1 L/D at melt temperatures of 210–250 °C; die gap is set to 0.5–0.8 mm, air gap 60–150 mm, and chill roll temperature 15–20 °C to quench the sealant layer before winding. Compliance is evaluated under 21 CFR 177.1350 for food-contact ethylene-vinyl acetate copolymers and EU Regulation (EU) No 10/2011 Annex I; total migration must not exceed 10 mg/dm², and specific migration of vinyl acetate must remain below the limit stated in the Union list for food-contact plastics. Terminal product types include medical form-fill-seal top webs, frozen food laminates, and heavy-duty packaging sealants.

Hot Melt Adhesive Base Polymer Compounding Parameters and Viscosity Control

In a jacketed sigma-blade mixer with nitrogen blanketing, EM518AA is charged at 25–35 wt% of the adhesive formulation, together with 30–45 wt% tackifier resin, 15–25 wt% paraffin wax, and 0.3–0.8 wt% hindered phenolic antioxidant. The polymer is melted at 150–170 °C; vacuum is applied at 0.08 MPa absolute to remove moisture and inhibit hydrolysis of vinyl acetate units. Batch discharge is filtered through a 100-mesh screen pack, and melt viscosity is determined at 180 °C by ASTM D3236-15 using a Brookfield Thermosel; viscosity is tracked against batch records because wax migration causes drift in open-time and set-speed performance. Exposure above 180 °C for more than 2 h accelerates acetic acid evolution, therefore oil-jacketed mixers should have high-temperature alarms and automatic discharge interlocks. Indirect food-contact adhesives fall under 21 CFR 175.105; the formulation must also comply with REACH Article 33 obligations if candidate list substances are present above 0.1 wt%. Terminal product types include case and carton sealing, bookbinding spine adhesives, and edge banding for furniture.

When EM518AA Is Substituted into Low-Smoke Halogen-Free Cable Sheathing Compounds

Because aluminum trihydrate and magnesium dihydrate require endothermic decomposition to release water vapour, filler loadings determine both flame retardancy and extrusion torque. A starting formulation uses 60–65 wt% surface-treated aluminum trihydrate, 30–35 wt% EM518AA as the polymer matrix, 2–5 wt% vinyl silane coupling agent, and 0.2–0.5 wt% antioxidant package. At filler loadings above 65 wt%, melt viscosity at 140 °C and 100 s⁻¹ rises sharply, and strand pelletising becomes unstable; below 60 wt%, limiting oxygen index may fail to reach the 30% threshold of ISO 4589-2:2017. Compounding is performed on a co-rotating twin-screw extruder with 44:1 L/D and segmented screws, operating at 200–350 rpm. The temperature profile from feed throat to die is held within 120–150 °C, with a melt temperature ceiling of 155 °C because aluminum trihydrate releases crystalline water above 180 °C; a melt pump holding 8–12 MPa discharge pressure is required to stabilise strand flow. Pre-drying is required at 60–70 °C for 4–6 h when ambient relative humidity exceeds 60%. Vent port flooding occurs when the melt temperature is below 120 °C due to incomplete polymer melting, while filler abrasion shortens screw rebuild cycles unless segmented elements are hardened. Additives that generate low-molecular-weight acids or amines should be avoided in this system because they can interact with the filler surface and shift pH during burn testing. Published compound-specific LOI data for EM518AA at each filler gradient is limited; therefore each lot should be benchmarked against the cited acceptance criteria using a laboratory batch before scale-up. Terminal product types include external sheathing for low-voltage power cables, control cable jackets, and building wire insulation in public transit and data centre installations.

Compliance matrix for EM518AA-based low-smoke halogen-free sheath compounds
Requirement	Test method	Acceptance criterion
Halogen acid gas evolution	IEC 60754-1	pH ≥ 4.3; conductivity ≤ 10 µS/mm
Acid gas corrosivity	IEC 60754-2	pH ≥ 4.3; conductivity ≤ 10 µS/mm
Limiting oxygen index	ISO 4589-2:2017	LOI ≥ 30%
Smoke density	IEC 61034-2	Transmittance ≥ 60%

Typically, EM518AA is selected as a carrier resin in pigment and additive concentrates because its vinyl acetate content provides wetting of organic pigments at loadings of 30–60 wt%. The carrier content is held at 25–50 wt% with 5–15 wt% polyethylene wax dispersant; this addition ratio maintains pellet integrity and prevents dust generation during dosing. The premix is fed into a co-rotating twin-screw extruder with 40:1 to 48:1 L/D, barrel temperatures 120–160 °C, and a gear melt pump before screen filtration; pellets are strand-cut under water and dried at 50–60 °C. Food-contact masterbatches must use only components cleared under EU Regulation (EU) No 10/2011 or 21 CFR 177.1350; heavy-metal restrictions apply under RoHS Directive 2011/65/EU Annex II and EN 71-3:2019 for toy applications. Terminal product types include film colour masterbatches, antioxidant concentrates for blown film, and light-stabiliser compounds for moulded consumer goods.

Injection Moulding of EM518AA in Heavy-Wall Closures Requires Short-Run Pressure and Temperature Control

EM518AA is injection moulded at 100 wt% or blended with LDPE at 20–50 wt% for flexible closures and protective caps. Melt temperature is held at 160–190 °C, mould surface temperature 20–40 °C, and injection pressure 60–100 MPa; hold pressure is reduced after gate freeze to avoid sink marks in thick sections. Mechanical properties are tested by ISO 527-2:2012; food-contact applications require clearance under 21 CFR 177.1350 and EU Regulation (EU) No 10/2011. Terminal product types include threaded protective caps, flexible tubing connectors, and push-fit plug closures for industrial shipping containers.

Typical Property Data and Test Methodology

The following values are class-typical ranges for an 18 wt% VA, 8 g/10 min EVA copolymer. The manufacturer’s certificate of analysis controls lot-specific conformance; the table does not define specification limits.

Property	Class-Typical Range	Test Method
Vinyl acetate comonomer content	18 wt%	Manufacturer internal method
Melt mass-flow rate	8 g/10 min	ASTM D1238 at 190 °C/2.16 kg
Density	0.938 g/cm³	ASTM D1505
Tensile strength at break	17–19 MPa	ASTM D638
Elongation at break	700–800 %	ASTM D638
Hardness	87–89 Shore A	ASTM D2240
Vicat softening point	58–62 °C	ASTM D1525
Melting peak temperature	84–86 °C	ASTM D3418

Property

Class-Typical Range

Test Method

Vinyl acetate comonomer content

18 wt%

Manufacturer internal method

Melt mass-flow rate

8 g/10 min

ASTM D1238 at 190 °C/2.16 kg

Density

0.938 g/cm³

ASTM D1505

Tensile strength at break

17–19 MPa

ASTM D638

Elongation at break

700–800 %

ASTM D638

Hardness

87–89 Shore A

ASTM D2240

Vicat softening point

58–62 °C

ASTM D1525

Melting peak temperature

84–86 °C

ASTM D3418

Because the 18 wt% vinyl acetate disrupts crystallite packing, EM518AA displays a broader melting endotherm and lower room-temperature flexural modulus than an 8 g/10 min low-density polyethylene. The residual crystallinity of the ethylene segments provides dimensional stability above ambient temperature, while the amorphous vinyl acetate domains contribute impact absorption, filler wetting, and compatibility with polar additives. The melt rheology is shear thinning; apparent viscosity decreases with increasing shear rate in capillary tests conducted according to ASTM D3835. No externally published complete viscosity curve at processing shear rates is included in the standard technical data sheet, but the 8 g/10 min melt flow value indicates moderate molecular weight and intermediate flow behaviour among EVA grades. In internal mixer operations, the product typically fluxes between 90 °C and 110 °C, and discharge from a roll mill is generally controlled at roll surface temperatures of 70–90 °C to avoid sticking. These temperatures are class-typical and must be confirmed with actual mechanical work input.

What Distinguishes EM518AA from Other EVA Copolymer Grades?

EVA grades within the same product family differ primarily in two independent variables: vinyl acetate content and melt mass-flow rate. In comparison with a 12 wt% VA grade of equivalent melt index, EM518AA exhibits lower crystallinity, lower Shore hardness, higher impact energy absorption at low temperature, and improved adhesion to polar substrates. In comparison with a 28 wt% VA grade of equivalent melt index, EM518AA retains higher room-temperature stiffness, lower surface tack, higher softening point, and better dimensional recovery after deformation. The melt mass-flow rate of 8 g/10 min defines an intermediate processing viscosity; a 3 g/10 min grade of the same VA content would provide higher melt strength and greater extrusion drawdown resistance, whereas a 25 g/10 min grade would permit lower injection pressures but would exhibit lower cohesive strength in adhesive and film applications. These differences are not additive; changing VA content and melt index simultaneously shifts mechanical, thermal, and rheological properties in non-linear directions that must be evaluated against the intended fabrication method.

Compared with maleic anhydride-modified EVA or ethylene-acrylic acid copolymers, EM518AA does not possess intentionally incorporated pendant carboxylic acid functionality. Adhesion to aluminium or polar engineering thermoplastics is therefore lower than acid-modified systems; however, the absence of reactive acid groups improves shelf stability and reduces corrosion potential on steel processing equipment when materials are dried appropriately.

In crosslinked closed-cell foam manufactured by compression moulding, ELEVATE EM518AA is typically combined with azodicarbonamide blowing agent, dicumyl peroxide crosslinking agent, zinc oxide activator, and fillers such as precipitated calcium carbonate. Mixing is carried out in an internal mixer or twin-screw extruder with 32:1 to 44:1 L/D ratio to disperse additives while maintaining a melt discharge temperature below 110 °C. This temperature constraint is critical because dicumyl peroxide has a one-hour half-life temperature near 135 °C; exceeding this threshold during compounding initiates premature crosslinking or scorch. After pelletising or calendering, the compound is expanded at 150–170 °C in a press or continuous oven where the decomposition rate of azodicarbonamide and the crosslinking rate of dicumyl peroxide must be balanced. If crosslinking occurs too slowly relative to gas evolution, cell walls rupture and the foam collapses; if crosslinking occurs too rapidly, expansion is suppressed and density remains high. The 18 wt% VA content contributes enough amorphous phase to accommodate filler and oil loadings without losing green strength during sheet formation. Pre-drying at 60 °C for 2–4 h is applied when storage relative humidity exceeds 60 % to reduce surface defects associated with moisture. Published data for this specific configuration is limited, and production trials are required to establish the exact peroxide and blowing agent ratios for a target foam density.

For injection-moulded foam footwear components, the same class of formulation is processed with screw plastication and mould filling at low to medium back pressure. Mould surface temperatures of 35–50 °C are used to control skin formation. The low melt viscosity of EM518AA permits short fill times but reduces melt strength during bubble growth; this limitation is addressed by raising crosslinking agent level or blending with a lower melt index EVA grade.

As a masterbatch carrier or impact modifier, EM518AA is used at addition levels typically below 20 wt% in polyolefin and engineering resin compounds. The polar vinyl acetate segments improve wetting of fillers such as calcium carbonate, alumina trihydrate, and magnesium hydroxide in flame-retardant polyolefin formulations. In these systems, the 8 g/10 min melt index enables rapid dilution into the host resin during twin-screw compounding at 180–200 °C. However, the product is not a coupling agent; interfacial adhesion to glass fibre or mineral surfaces is lower than maleic anhydride-grafted polyolefins. Flame-retardant compounds containing high loadings of metal hydroxides may require process stabilizers to prevent viscosity rise associated with acetate decomposition above 210 °C. Published data for this specific configuration is limited.

Melt Temperature Limits Govern Barrel Zone Profiling

In single-screw extrusion, a general-purpose polyolefin screw with 24:1 to 32:1 L/D and a compression ratio of 2.5:1 to 3.5:1 is suitable for EM518AA. Barrel temperatures are typically profiled from 150 °C in the feed zone to 190 °C at the adapter, with a maximum melt temperature of 210 °C. Operation above 220 °C can thermally degrade the vinyl acetate segments, liberating acetic acid and causing darkening or metallic corrosion in downstream equipment. The 8 g/10 min melt index allows moderate head pressures and permits extrusion through conventional screen packs and breaker plates. In injection moulding, the melt is processed at 180–200 °C with mould temperatures of 20–40 °C for rapid solidification; higher mould temperatures may increase cycle time and can promote surface tack. Hot runner channels should be streamlined and free of dead spots, and purging with a thermally stable polyolefin after shutdown is recommended. Repeated extrusion history can be monitored by melt mass-flow rate retention measured according to ASTM D1238; a significant upward shift indicates molecular weight reduction due to chain scission. Moisture above 0.05 wt% can cause surface splay; drying at 60 °C for 2–4 h is recommended when exposure to relative humidity above 60 % has occurred.

To Determine Conformity, Current Supplier Certification Is Reviewed

Regulatory evaluation requires review of the latest supplier certificate of analysis, safety data sheet, and product regulatory statement. EVA copolymers intended for food-contact applications may be evaluated under 21 CFR 177.1350, which lists ethylene-vinyl acetate copolymers permitted for use in contact with food under specified extractive and compositional conditions. The base resin does not carry a blanket approval for food-contact use; the converter must conduct end-use migration testing appropriate to the food type and contact conditions. For European Union operations, the grade is subject to REACH Regulation EC 1907/2006. The manufacturer’s registration covers the substance as registered; any use not described by the supplier should be confirmed. The product is not formulated with intentionally added cadmium, lead, mercury, or hexavalent chromium and is typically suitable for projects referencing RoHS Directive 2011/65/EU, but lot-level verification is required because raw-material trace contamination can occur. The following references summarize the main compliance contacts.

Reference	Scope	Operational Boundary
21 CFR 177.1350	Ethylene-vinyl acetate copolymer food-contact use	End-use migration testing required; not a blanket approval
REACH EC 1907/2006	European chemical registration and communication	Only registered uses are covered
RoHS 2011/65/EU	Restricted substance screening	Lot-level verification required
ASTM D1238	Melt mass-flow rate quality control	Not a safety or regulatory standard

Reference

Scope

Operational Boundary

21 CFR 177.1350

Ethylene-vinyl acetate copolymer food-contact use

End-use migration testing required; not a blanket approval

REACH EC 1907/2006

European chemical registration and communication

Only registered uses are covered

RoHS 2011/65/EU

Restricted substance screening

Lot-level verification required

ASTM D1238

Melt mass-flow rate quality control

Not a safety or regulatory standard

When EM518AA Is Specified in Hot-Melt Adhesive Systems

In hot-melt adhesive compounding, ELEVATE EM518AA functions as the polymeric backbone in formulations containing tackifying resins, paraffin or microcrystalline wax, and antioxidant. The 18 wt% vinyl acetate content provides polarity for adhesion to paper, cardboard, wood, and coated surfaces, while the 8 g/10 min melt index yields a lower application viscosity than high-molecular-weight EVA grades. Typical hot-melt formulations based on medium-VA EVA include 25–40 wt% polymer, 30–50 wt% tackifier, and 5–30 wt% wax; these ranges are class-typical and must be rebalanced for the specific substrate and application temperature. Mixing is performed in heated vertical or horizontal mixers under nitrogen blanket at 150–180 °C, with high shear avoided after wax addition to limit temperature overshoot. Thermal degradation in the hot-melt is monitored by viscosity, ring-and-ball softening point according to ASTM E28, and Gardner color. The product does not inherently supply long-term heat stabilisation; an antioxidant system is required for sustained processing above 160 °C. Compared with a higher-VA EVA grade, EM518AA provides better cohesive strength and heat resistance after set-up but lower adhesion to highly polar or plasticized substrates. Compared with a lower-VA EVA grade, it provides improved surface wetting and low-temperature flexibility but can require more stabilizer due to the higher amorphous content. Application through slot-die, bead, or spiral-spray systems at 170–190 °C is possible; nozzle build-up may occur in dead zones due to degradation.

HS Code	591654
Product	ELEVATE EM518AA Ethylene Vinyl Acetate Copolymer
Vinyl Acetate Content	18%
Melt Flow Rate 190 C 2 16 Kg	2.5 g/10 min
Density	0.940 g/cm³
Melting Point	86 °C
Vicat Softening Point	63 °C
Tensile Strength At Break	25 MPa
Elongation At Break	800%
Flexural Modulus	35 MPa
Shore A Hardness	90
Brittleness Temperature	-80 °C
Crystallization Temperature	65 °C
Glass Transition Temperature	-30 °C

Packing	ELEVATE EM518AA Ethylene Vinyl Acetate Copolymer is supplied as free-flowing pellets in 25 kg sealed polyethylene bags, palletized and stretch-wrapped.
Container Loading (20′ FCL)	20′ FCL container loading of ELEVATE EM518AA Ethylene Vinyl Acetate Copolymer, ensuring secure, dry stowage and proper ventilation.
Shipping	ELEVATE EM518AA Ethylene Vinyl Acetate Copolymer ships as solid pellets in moisture-protective bags, bulk bags, or hopper containers. Avoid extreme heat and ignition sources, as dust may form combustible mixtures. Store dry, ventilated, and away from oxidizers. Load and unload with clean equipment to prevent contamination, and follow standard non-hazardous material transport guidelines.
Storage	Store ELEVATE EM518AA in a cool, dry, well-ventilated area, away from direct sunlight, heat, and ignition sources. Keep containers tightly sealed to prevent moisture absorption. Avoid exposure to strong oxidizers. Maintain moderate temperatures to preserve material properties. Ensure proper handling to prevent dust accumulation and static discharge. Use within recommended shelf life.
Shelf Life	Shelf life is typically two years from manufacture when stored in original packaging under cool, dry conditions.

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