| HS Code | 139542 |
| Material | EVAtech 140S/28G EVA Copolymer Compound, Crosslinkable Foam Grade |
| Resin Type | Ethylene Vinyl Acetate (EVA) Copolymer |
| Vinyl Acetate Content | 28 wt% |
| Melt Flow Rate 190 C 2 16kg | 14 g/10 min |
| Density | 0.954 g/cm³ |
| Melting Point Dsc | 68 °C |
| Vicat Softening Point | 46 °C |
| Tensile Strength At Break | 16 MPa |
| Elongation At Break | 800% |
| Hardness Shore A | 89 |
| Glass Transition Temperature | -30 °C |
| Crosslinking Behavior | Peroxide-crosslinkable; designed for foam processing |
| Foam Type | Closed-cell crosslinked foam |
| Low Temperature Flexibility | Excellent |
As an accredited EVAtech 140S/28G EVA Copolymer Compound,Crosslinkable Foam Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied in 25 kg polyethylene bags, palletized and shrink-wrapped for safe handling and storage. |
| Container Loading (20′ FCL) | One 20′ FCL container holds EVAtech 140S/28G crosslinkable EVA copolymer compound, foam grade, securely packed for transport. |
| Shipping | EVAtech 140S/28G is shipped as solid pellets in moisture-proof polyethylene-lined bags or bulk containers. Ensure dry, ventilated conditions to prevent clumping. Not classified as hazardous goods; transport via standard freight respecting low-stacking limits. Avoid prolonged heat exposure and direct sunlight. Handle with clean equipment to maintain product purity. |
| Storage | Store in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep containers tightly sealed to prevent moisture, dust, or contamination. Maintain stable temperature and avoid prolonged storage above recommended conditions. Use FIFO stock rotation; shelf life may be limited, so follow supplier guidelines for optimal performance. |
| Shelf Life | Shelf life is 12 months from manufacture date when stored unopened in a cool, dry area away from direct sunlight. |
Compression-molded midsoles using EVAtech 140S/28G are produced from a crosslinkable ethylene-vinyl acetate compound with nominal 28 wt% vinyl acetate comonomer content and a melt index of 140 g/10 min when measured under ISO 1133-1:2022 at 190 °C/2.16 kg. The compound is mixed in a tangential internal mixer at a fill factor of 0.78 and a jacket temperature of 95 °C to 105 °C, with rotor speed held between 35 rpm and 45 rpm. Stock is dropped at 108 °C to 115 °C onto a two-roll mill maintained at 85 °C to 95 °C; dicumyl peroxide is added at this stage only after the stock surface temperature falls below 95 °C to prevent scorch. Azodicarbonamide blowing agent is added with zinc oxide and zinc stearate on the cooling mill. The resulting preform is compression molded in a hydraulic press at 170 °C to 180 °C for 8 min to 12 min, with platen pressure from 150 kg/cm² to 200 kg/cm². Under these conditions the blowing agent decomposes after the cure system has generated sufficient melt strength to stabilize expanding cells. Molded densities range from 0.16 g/cm³ to 0.22 g/cm³ when measured per ISO 845:2006. Hardness values fall between Shore C 45 and Shore C 55 under ASTM D2240-15. Tensile strength and elongation are checked per ISO 1798:2008 on dumbbell specimens cut from the foam; typical acceptance values in footwear production require tensile strength above 2.0 N/mm² and elongation above 180%. Compression set is measured per ASTM D395-18 Method B at 50% deflection for 24 h at 23 °C. Rebound resilience is measured on a Lupke pendulum per ASTM D2632-15.
| Formulation parameter or property | Low-density midsoles | Standard midsoles | High-abrasion midsoles |
|---|---|---|---|
| EVAtech 140S/28G | 100 phr | 100 phr | 100 phr |
| Azodicarbonamide | 5.5 phr | 4.0 phr | 3.0 phr |
| Dicumyl peroxide | 0.7 phr | 0.8 phr | 0.9 phr |
| Zinc oxide | 2.0 phr | 1.5 phr | 1.0 phr |
| Zinc stearate | 0.8 phr | 0.8 phr | 0.5 phr |
| Calcium carbonate | 0 phr | 10 phr | 20 phr |
| Molded density, ISO 845:2006 | 0.11 g/cm³ | 0.18 g/cm³ | 0.25 g/cm³ |
| Hardness Shore C, ASTM D2240-15 | 40 | 50 | 58 |
| Compression set after 24 h at 50%, ASTM D395-18 | 18% | 12% | 8% |
Production-scale failure modes in midsole molding are dominated by pre-scorch and cell coalescence. If the mixed batch remains on a hot mill above 95 °C for more than 6 min, peroxide-induced crosslinking raises Mooney viscosity before the blowing agent has decomposed, and the subsequent foam shows a hard, poorly expanded core. A second failure mode occurs when azodicarbonamide particle size distribution shifts; sieve residue above 45 µm on a 40-mesh screen delays gas evolution and enlarges average cell diameter beyond 0.5 mm. Such boards exhibit visible pinholes and reduced split tear resistance. Demolding before the press platens cool below 70 °C can produce surface blisters because residual gas pressure inside closed cells exceeds the tensile strength of the partially crystallized surface skin. The addition of calcium carbonate above 20 phr raises compound viscosity and reduces rebound but improves dimensional stability; beyond 30 phr the cured foam loses tear strength and becomes difficult to skive. Moisture uptake is low in the neat copolymer, but when calcium carbonate or hygroscopic fillers are used, pre-drying at 60 °C for 2 h is necessary if storage relative humidity exceeds 60%. Basic activators such as magnesium oxide or amine-based additives are avoided because they alter the azodicarbonamide decomposition exotherm and can produce uneven cell structure or premature crosslinking.
Crosslinked orthotic block stock made from EVAtech 140S/28G is typically foamed to a density of 0.10 g/cm³ to 0.15 g/cm³ and then skived into sheets of 1.5 mm to 4.0 mm for die-cut insoles. Tear strength is controlled primarily by gel content, average cell size, and the presence of low-molecular-weight residues. Gel content after xylene extraction at 110 °C for 24 h per ASTM D2765-16 should fall between 60% and 75%. Below 60% gel content the foam tears at cell walls under repeated flexing; above 80% the material becomes brittle and difficult to thermoform or adhesively bond. Blowing agent loading in this application is held between 4.0 phr and 5.0 phr, while dicumyl peroxide is reduced to 0.5 phr to 0.7 phr to maintain a fine cell structure with average cell diameter below 0.4 mm. The 28 wt% vinyl acetate comonomer reduces crystallinity and gives the skived sheet a dry, rubbery feel at body temperature. For orthotic products marketed as medical devices, finished components may require biocompatibility evaluation under ISO 10993-5 and ISO 10993-10; the raw compound is not certified as medical grade. Tensile properties are measured per ISO 1798:2008, and tear resistance is measured per ISO 8067:2018. Published data for this specific configuration in orthotic block stock is limited, so incoming lots should be qualified against a control material using gel content, density, and compression set before production release. The terminal product includes contoured insoles, heel wedges, and metatarsal pads.
Laminated exercise mat constructions using EVAtech 140S/28G begin with crosslinked foam sheets at a density of 0.11 g/cm³ to 0.13 g/cm³. The sheets are produced on a continuous compression press, skived, and then thermally laminated at 120 °C to 140 °C with a surface film or textured polyolefin layer. Bonding is performed at nip pressure of 4 bar to 6 bar and a line speed of 6 m/min to 10 m/min. The formulation uses 3.5 phr to 4.5 phr azodicarbonamide and 0.6 phr to 0.8 phr dicumyl peroxide, with 1.5 phr zinc oxide as a blowing activator. Density is checked per ISO 845:2006. Thickness tolerance across a 1.8 m width is held within ±0.25 mm. Rebound retention after accelerated flex testing is monitored using ASTM D395-18 Method B compression set; mats with gel content below 65% exhibit permanent set above 15% and are rejected for high-cycle use. Finished mats are tested for slip resistance under DIN 51130 or ASTM D2047 depending on the target market. REACH Annex XVII restrictions apply to polycyclic aromatic hydrocarbons and phthalates in consumer mats. The end products include yoga mats, gym floor tiles, and anti-fatigue standing mats.
Marine buoyancy billets and dock fenders require closed-cell EVA foam with density from 0.06 g/cm³ to 0.09 g/cm³. When molding temperature is held below 175 °C, residual azodicarbonamide remains undecomposed in the core. The unreacted blowing agent later decomposes during service heating or cutting, creating internal voids and increasing water absorption. For marine billets, mold temperature is therefore set at 175 °C to 185 °C, with cure time extended to 15 min to 20 min for block thickness above 50 mm. The 28 wt% vinyl acetate content preserves low-temperature flexibility in seawater. Water absorption is measured after full immersion for 7 days; acceptance requires volume uptake below 3% when tested on a 50 mm × 50 mm × 25 mm specimen cut from the billet core. The test method is typically ASTM D3575 suffix L, although some specifications refer to ISO 2896:2001. Buoyancy calculations must use measured density from the billet core, not the nominal density of the compound. Closed-cell content is verified by gas pycnometry using ISO 4590:2016 or ASTM D6226-21 where applicable; values below 90% indicate cell wall rupture and are cause for rejection. Stabilizer packages are selected for UV resistance; unprotected foam chalks within 6 months under tropical sunlight. Published data for EVAtech 140S/28G in marine billet form is limited, so suppliers should qualify each block size and density before bid submission. The terminal products include foam-filled fenders, marker buoys, and personal flotation components.
Automotive interior padding manufactured from EVAtech 140S/28G is compression molded into sheets of 0.08 g/cm³ to 0.12 g/cm³ and then die-cut for instrument panel padding, door trim absorbers, and floor carpet underlay. The crosslinked closed-cell structure provides acoustic insertion loss and vibration damping in the 500 Hz to 2000 Hz frequency range. Flame performance is verified under FMVSS 302 and CMVSS 302; a horizontal burn rate below 100 mm/min is the usual pass criterion. Volatile organic compound emissions are tested by VDA 278 or OEM-specific thermal desorption methods; current programs often require fogging condensate below 2 mg and total VOC below 100 µg/g. To meet these limits, the foam is oven-post-cured at 70 °C to 80 °C for 4 h to 6 h to reduce ammonia and blowing agent residues. Compression deflection is measured at 25% deflection per ISO 3386-1:1986; typical values for a 0.10 g/cm³ sheet are 30 kPa to 60 kPa. The compound must be free of restricted substances under REACH Annex XVII and the ELV Directive for lead, cadmium, mercury, and hexavalent chromium. Adhesive bonding to polypropylene or ABS interior substrates is performed after corona treatment at 38 mN/m to 44 mN/m surface energy; solvent-based primers are avoided because they add VOC. The terminal products include dash insulators, wheel arch liners, and HVAC gaskets.
| Application | Test method | Typical acceptance |
|---|---|---|
| Footwear midsoles | ISO 845:2006, ASTM D2240-15, ASTM D395-18, ISO 1798:2008 | Density 0.16–0.22 g/cm³; Shore C 45–55; compression set <15% |
| Orthotic block stock | ASTM D2765-16, ISO 8067:2018, ISO 10993-5 | Gel content 60–75%; tear above control lot |
| Exercise mats | ISO 845:2006, ASTM D395-18, DIN 51130 | Compression set <15%; pass slip rating |
| Marine buoyancy | ASTM D3575 suffix L, ISO 4590:2016 | Water absorption <3%; closed-cell content >90% |
| Automotive interior | FMVSS 302, VDA 278, ISO 3386-1:1986 | Burn rate <100 mm/min; total VOC <100 µg/g |
| Concrete joint filler | ASTM D1751, ASTM D994 | Compression recovery ≥75% at 50% deflection |
Preformed EVAtech 140S/28G foam strips with nominal density from 0.12 g/cm³ to 0.16 g/cm³ and closed-cell structure are used as concrete expansion joint fillers under ASTM D1751 and ASTM D994, requiring compression recovery of at least 75% when tested at 50% deflection per ASTM D1751.
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EVAtech 140S/28G is a formulated ethylene-vinyl acetate copolymer compound intended for chemically crosslinked foam conversion. The grade designation identifies a nominal vinyl acetate content of 28 wt% and a melt flow index of 140 g/10 min measured at 190 °C under 2.16 kg load according to ISO 1133-1:2022. The compound is supplied as cylindrical pellets with a maximum moisture content of 0.1 wt% by Karl Fischer titration and a bulk density of approximately 0.58 g/cm³. The unfilled base polymer exhibits a density of 0.950 g/cm³ per ISO 1183-1:2019, tensile strength at break of 12–16 MPa per ISO 527-2:2012, elongation at break of 800–1000% per ISO 527-2:2012, and Shore A hardness of 80–85 per ISO 7619-1:2010. These values are typical property envelopes and do not constitute specification limits. The grade is used in footwear midsoles, orthotic insoles, sports padding, thermal insulation sheet, pipe insulation, marine buoyancy products, and automotive interior padding where controlled foam density and closed-cell structure are required.
The differential scanning calorimetry melting peak of the base polymer is approximately 72 °C per ISO 11357-3:2018, with crystallization onset near 54 °C. The Vicat softening temperature A/10 is approximately 45 °C per ISO 306:2022. These values are lower than those of an 18 wt% VA EVA foam grade and reflect reduced crystalline domains from the 28 wt% vinyl acetate comonomer content. For peroxide cure, dicumyl peroxide exhibits a one-hour half-life temperature near 135 °C and a half-life of less than 1 min above 175 °C. When azodicarbonamide is used as the blowing agent, its decomposition in the presence of 1–2 phr zinc oxide or a dicarboxylic acid kicker is shifted to approximately 155–165 °C. The resulting processing window in compression molding is approximately 165–180 °C; below 165 °C peroxide decomposition is slow and cell size becomes coarse, while above 180 °C the blowing gas evolves before sufficient crosslink density develops and internal cell-wall rupture can occur. Production data from 75 L internal mixers indicate that batch-to-batch variance in gel content remains below 2 percentage points when drop temperatures are held within 105–110 °C. Gel content after crosslinking is typically measured by extraction in boiling xylene for 24 h according to ASTM D2765-16; a target gel content of 70–80% is needed for closed-cell foam with acceptable compression set. Below 60%, cells collapse; above 85%, shrinkage and skin cracking increase.
When compression molding is selected as the primary conversion route, the compound is typically pre-blended with 0.8–1.2 phr dicumyl peroxide and 3–5 phr azodicarbonamide on a two-roll mill with a friction ratio of 1:1.2 and roll temperatures of 75–85 °C. In a 75 L tangential internal mixer, a fill factor of 0.75 and drop temperature of 105–110 °C are used to disperse additives without scorch; the peroxide is added last and mixed for no more than 60 s after incorporation. The milled sheet is then cut and placed into a compression press cavity. Molding temperatures of 165–180 °C, press pressure of 150–200 kg/cm², and cure time of 10–20 min depending on part thickness are typical. Thick sections above 20 mm require stepped cure profiles to prevent exothermic overshoot, because azodicarbonamide decomposition is exothermic and can raise core temperature beyond the skin temperature. Batch-to-batch variability in foam density is commonly controlled within ±0.010 g/cm³ when the pre-blend is aged no more than 4 h before molding and the two-roll mill nip is maintained at 2 mm. Published data for this specific configuration is limited; converter-scale trials are required for part-specific dimensional stability.
Compared with foam grades based on 18 wt% VA copolymers, EVAtech 140S/28G produces crosslinked foam with lower Shore A hardness and lower peel strength at equivalent density, but with improved cold-flex resistance and greater filler acceptance. The 140 g/10 min melt flow index is substantially higher than conventional extrusion foam grades with 2.5 g/10 min MI; this reduces fill time in injection foam molding and permits thinner cell walls in complex geometries, but it also reduces melt strength during free-foam extrusion. As a result, extrusion lines using EVAtech 140S/28G require lower draw-down ratios and more precise gas counterpressure when foaming is initiated at the die. The following indicative comparison illustrates typical property differences among EVA foam grades at equivalent cure and blowing-agent loading:
| Property | EVAtech 140S/28G | EVA 18% VA MI 2.5 | EVA 28% VA MI 25 |
|---|---|---|---|
| Vinyl acetate content | 28 wt% | 18 wt% | 28 wt% |
| Melt flow index at 190 °C/2.16 kg | 140 g/10 min | 2.5 g/10 min | 25 g/10 min |
| Unfilled base hardness | 80–85 Shore A | 90–95 Shore A | 75–82 Shore A |
| DSC melting peak | 72 °C | 84 °C | 73 °C |
| Melt strength during foam extrusion | Low–moderate | High | Moderate |
| Injection fill behavior | Short fill time | Long fill time | Moderate fill time |
| Primary processing conflict | Cell coalescence if cure onset is delayed | Poor thin-wall flow | Higher shrink after demolding |
The high vinyl acetate content reduces crystalline melting point and increases polarity. This improves compatibility with polar fillers and plasticizers, but it also reduces resistance to hydrocarbon solvents and increases water vapor transmission compared with 18 wt% VA EVA. The high melt flow index reduces molecular weight and zero-shear viscosity; therefore, the grade is not intended for unsupported blown film or extrusion coating where high melt strength is the primary process requirement. For foam extrusion, the grade should be used with a chemical crosslinking agent and a die temperature below 110 °C to maintain cell structure.
The melt flow index of 140 g/10 min places EVAtech 140S/28G in the high-flow EVA class. In injection foam molding, barrel temperatures are typically set between 70 °C and 90 °C from feed to nozzle, with mold temperature maintained at 170–185 °C to trigger peroxide cure and blowing-agent decomposition after cavity fill. Screw L/D ratios of 22:1 to 24:1 and compression ratios of 2.0:1 to 2.4:1 are used to minimize premature shear heating. Injection speeds are set high enough to complete fill before the melt front reaches 160 °C, because cure onset before fill completion causes knit lines and nonuniform cell distribution. Clamp force requirements depend on projected foam area and foaming pressure; molds with venting grooves of 0.03–0.05 mm depth are used to release gas while preventing flash. For extrusion foam sheet, a grooved-barrel extruder with L/D 30:1 and a melt pump is typically used, with melt temperature limited to 90–100 °C at the die to prevent premature blowing. The high melt flow allows throughput increases, but the screen pack and die land length must be adjusted to prevent pressure pulsation. Production-scale data from foam extrusion lines show that melt fracture and cell wall rupture increase when melt temperature at the die exceeds 110 °C for this grade.
When the converter replaces a lower-MI EVA with EVAtech 140S/28G in an existing injection foam mold, the fill phase shortens; however, the switch without reducing barrel temperature can cause flash at parting lines and gas burn marks at knit lines. Tooling with vent depths appropriate for 0.15 g/cm³ foam expansion is required. Run-to-run density control is maintained by monitoring melt cushion and injection pressure; the high melt flow index reduces the pressure required to fill the cavity but also narrows the gate freeze window. Published mold-filling simulation data for this specific grade is limited; gate dimensions should be validated with actual part trials.
In converting environments where relative humidity exceeds 60%, pellets should be pre-dried at 60 °C for 4 h with a desiccant dryer or vacuum dryer to maintain moisture below 0.1 wt%. Although the EVA base polymer is not strongly hygroscopic, hygroscopic additives in some pre-compounded variants can generate surface defects during foaming. The compound should not be combined with amine-based antioxidants, sulfur-donor cure systems, or strongly acidic fillers; amines can scavenge free radicals and reduce peroxide cure efficiency, while acidic fillers can promote premature azodicarbonamide decomposition and uneven cell growth. Storage conditions below 30 °C and away from ultraviolet sources are specified to preserve the stabilization package. Under these conditions, the product is routinely stored for up to 12 months without significant MI drift. The compound is formulated without intentionally added phthalates, lead stabilizers, or brominated flame retardants, and RoHS screening under 2011/65/EU is available. Food-contact suitability of the base EVA resin may be evaluated under FDA 21 CFR 177.1350; however, the crosslinked foam formulation must be verified by the converter for the final article and specific additive package.
Peroxide concentration is the primary cure variable controlling gel content and foam morphology. At less than 0.8 phr dicumyl peroxide, crosslink density remains insufficient to stabilize expanding cells; foam density varies by more than 0.020 g/cm³ across a molded part, and compression set at 50% deflection for 6 h at 23 °C exceeds 25%. At more than 1.2 phr, gel content rises above 85% and the crosslinked network restricts gas expansion, producing dense skin layers, high shrinkage, and increased Shore A hardness. Overcure also reduces tear strength because excessive crosslink density embrittles the cell walls. The following indicative data are for a compression-molded foam at 0.15 g/cm³ target density with 4 phr azodicarbonamide and 1 phr zinc oxide; values were obtained on a 75 L internal mixer and a 165–175 °C press cycle:
| DCP loading | Gel content | Foam density | Compression set after 24 h | Observed process defect |
|---|---|---|---|---|
| 0.6 phr | 52–58% | 0.17–0.19 g/cm³ | 28–35% | Cell collapse, coarse cells |
| 1.0 phr | 74–80% | 0.14–0.16 g/cm³ | 15–20% | Uniform closed cells |
| 1.4 phr | 85–90% | 0.13–0.15 g/cm³ | 10–14% | Skin cracking, high shrinkage |
When accelerator-modified blowing agents are used, the effective peroxide range may narrow to 0.9–1.1 phr because the gas evolution onset shifts closer to the cure onset. Molders using hot mold release above 180 °C should reduce peroxide toward the lower limit to compensate for faster cure. Conversely, thick parts with slow heat transfer can require a slight increase to 1.1–1.2 phr to ensure gel content at the core. No additional processing of the compound should be attempted after the mixed batch has partially scorched; scorched material exhibits a rough pellet surface, elevated melt viscosity, and nonuniform foam density.
