| HS Code | 157633 |
| Grade Name | Formosa Taisox EVA 7470K |
| Chemical Name | Ethylene-vinyl acetate copolymer |
| Cas Number | 24937-78-8 |
As an accredited Formosa Taisox EVA 7470K factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Formosa Taisox EVA 7470K is supplied in moisture-resistant 25 kg bags, typically 1,000 kg per pallet. |
| Container Loading (20′ FCL) | Formosa Taisox EVA 7470K is packed in 25 kg bags, palletized, and loaded into a 20′ FCL container for export. |
| Shipping | Formosa Taisox EVA 7470K is an ethylene-vinyl acetate copolymer resin supplied as solid pellets. It is not classified as dangerous goods for transport and is not regulated under ADR, IMDG, or IATA. Ship in dry, covered containers away from heat and moisture using standard industrial packaging and non-hazardous labeling. |
| Storage | Store Formosa Taisox EVA 7470K in a cool, dry, well-ventilated area away from direct sunlight, heat, sparks, and open flames. Keep bags closed and palletized off the floor to prevent moisture pickup and contamination. Avoid prolonged high-temperature exposure and prevent dust generation or static buildup. Use original packaging and follow local fire and housekeeping regulations. |
| Shelf Life | Formosa Taisox EVA 7470K typically has a 24-month shelf life in original unopened packaging, stored cool, dry, and away from sunlight. |
Formosa Taisox EVA 7470K is a high-vinyl-acetate ethylene-vinyl acetate copolymer with a nominal vinyl acetate content of 26 wt% and a melt mass-flow rate of 4 g/10 min at 190 °C/2.16 kg determined according to ISO 1133-1:2022. The comonomer content provides polar substrate wetting, high filler acceptance, and low-temperature flexibility; the 4 g/10 min MFR sets a processing boundary in thin-wall injection moulding and high-speed extrusion. Converters should treat the following scenarios as technical working ranges, not as universal formulations; end-use regulatory conformity depends on the complete formulation, conversion conditions, and Article-level restrictions under REACH EC 1907/2006.
In footwear midsole conversion, Formosa Taisox EVA 7470K functions as the high-vinyl-acetate component in a mixed-polymer system where a lower-VA EVA grade is used to maintain melt strength and cell uniformity. Production-scale batch cards place EVA 7470K at 55 phr to 75 phr of total polymer, with an 18 wt% to 22 wt% VA EVA at 25 phr to 45 phr. The blowing and curing system comprises azodicarbonamide at 2.5 phr to 4.0 phr, dicumyl peroxide at 0.7 phr to 1.2 phr, zinc oxide at 0.5 phr to 1.0 phr, and zinc stearate at 0.2 phr to 0.5 phr. Calcium carbonate may be added at 5 phr to 15 phr to adjust cell size and material cost; excess filler above 15 phr is reported to reduce rebound and increase compression set. Mixing is performed in a Banbury-type internal mixer with a drop temperature held below 110 °C to prevent premature dicumyl peroxide decomposition; the batch then passes through a two-roll mill, is pelletized, and is converted by injection foam moulding or compression foam moulding at 155 °C to 170 °C with cure cycles of 4 min to 9 min. A persistent production failure mode is drift in the base resin melt mass-flow rate: a variation of 0.5 g/10 min alters cavity fill, cell-size distribution, and final part density, so incoming shipments should be checked against ISO 1133-1:2022 and the converter’s agreed tolerance band. Amine-based nucleating packages should be avoided because amine species can prematurely consume peroxide radicals and destabilize the cure profile. Terminal parts include running-shoe midsoles, slipper soles, orthotic insoles, and comfort footbeds. Compliance testing for converted foam uses ASTM D395-18 Method B for compression set, ISO 845:2006 for apparent density, ISO 868:2003 for Shore hardness, and ISO 17707:2018 for flexing resistance; Article-level obligations under REACH EC 1907/2006 Annex XVII apply to the finished footwear component.
Hot-melt adhesive compounding with EVA 7470K uses the 26 wt% vinyl acetate content to improve wetting on paperboard, coated liner, and book block paper while retaining a moderate 4 g/10 min melt flow rate that limits adhesive penetration into porous stock at application temperature. Typical industrial formulas place the resin at 25 wt% to 40 wt% of total formula; tackifier resin, usually hydrogenated C5 or C9, is added at 35 wt% to 50 wt%; Fischer-Tropsch or microcrystalline wax is metered at 15 wt% to 25 wt% to shorten set time; and a hindered phenolic antioxidant is held at 0.2 wt% to 0.5 wt% to reduce viscosity drift in heated holding tanks. Production equipment consists of a jacketed vertical mixer at 160 °C to 180 °C, followed by strand extrusion and cooling into pillow granules, slugs, or 12 mm to 43 mm cartridges. Application equipment operates at 170 °C to 190 °C; lower temperatures increase stringing and poor transfer, while holding above 200 °C accelerates acetic acid liberation from vinyl acetate decomposition and changes tack, colour, and corrosivity. The main process boundary is therefore residence time at elevated temperature during intermittent line stoppages. Converted article types include corrugated case sealing, bookbinding, edge banding, and paperboard tray lamination. Regulatory benchmarks for food packaging adhesive are 21 CFR 175.105 for indirect food-contact adhesives and, where the EVA layer itself forms the food-contact surface, 21 CFR 177.1350; the complete formula and migration test remain the converter’s responsibility under REACH EC 1907/2006.
In halogen-free flame-retardant wire and cable compounding, EVA 7470K is selected as the high-VA base resin because the polar acetate comonomer enables higher aluminium trihydroxide or magnesium dihydroxide loadings without gross embrittlement. Reference compound ranges on production lines use EVA 7470K at 30 wt% to 45 wt% of total compound; an LLDPE or LLDPE-g-MAH co-carrier at 10 wt% to 20 wt%; surface-treated ATH at 50 wt% to 65 wt% or magnesium dihydroxide at 50 wt% to 60 wt%; a vinyl silane coupling agent at 0.5 phr to 1.5 phr; a hindered phenolic antioxidant at 0.3 phr to 0.8 phr; and a processing lubricant at 1 phr to 3 phr. Compounding is carried out on a co-rotating twin-screw extruder with an L/D ratio of 40:1 to 52:1, segmented screws, and vacuum venting at −0.08 MPa to −0.09 MPa downstream of filler addition. Barrel temperatures are set from 130 °C in the feed section to 160 °C at the die. ATH must be pre-dried at 80 °C to 100 °C for 4 h to 6 h when ambient relative humidity exceeds 60 %; moisture entering the extruder vaporizes at the vent, creating strand porosity and reducing pellet density. The process conflict occurs at filler loadings above 65 wt%, where torque approaches the machine drive limit and melt pressure becomes sensitive to soot or carbon black contamination from recycled cable scrap. Melt temperature must not exceed 190 °C for ATH-based formulations because aluminium trihydroxide releases water above approximately 180 °C and the flame-retardant effect degrades. Terminal products include low-voltage insulation, bedding compound, and sheathing for building wire and control cable, using production-scale extrusion lines with coarse screw design and preheated dies. Compliance is evaluated against IEC 60332-1-2:2004 for vertical flame propagation, IEC 60754-1:2011 for halogen acid gas content, and IEC 60754-2:2011 for acidity; the RoHS 2011/65/EU Annex II restrictions apply to the electrical cable article.
Continuous and press-foamed sheet stock for fitness, leisure, and protective packaging uses EVA 7470K to reduce hardness and increase low-temperature flexion relative to lower-VA EVA, but the higher comonomer content reduces melt strength and requires blending with a lower-VA grade to prevent cell collapse during expansion. Sheet formulations place EVA 7470K at 65 wt% to 80 wt% of total polymer and an 18 wt% to 22 wt% VA EVA at 20 wt% to 35 wt%. Azodicarbonamide is added at 2.5 phr to 3.5 phr; dicumyl peroxide at 0.8 phr to 1.1 phr; zinc oxide at 0.5 phr to 1.0 phr; and zinc stearate at 0.5 phr to 1.0 phr. The process uses a kneader-type mixer with a drop temperature below 110 °C, followed by two-roll sheet formation and hot-press foaming at 165 °C to 175 °C under hydraulic pressure of 10 MPa to 20 MPa. During the final expansion step, the sheet is transferred to a cooling press to set the closed-cell structure; transfer delay is a critical variable because premature cooling freezes surface cells and produces dense skins, while delayed transfer allows internal gas coalescence. Converted product types include yoga mats, anti-fatigue mats, interlocking child-play tiles, knee pads, and die-cut protective packaging inserts. Compliance for childcare and fitness articles is usually benchmarked against EN 71-3:2019 migration of elements and the phthalate restrictions under REACH EC 1907/2006 Annex XVII; packaging inserts in electrical equipment require RoHS 2011/65/EU Article-level screening for restricted substances.
For thin-wall gaskets and soft industrial parts, EVA 7470K uses the 26 wt% vinyl acetate content to achieve low Shore A hardness without plasticizer addition, but the 4 g/10 min melt mass-flow rate increases fill pressure in thin sections and demands a larger hydraulic margin than high-MFR EVA grades. Moulding trials on production machines show that melt temperatures of 160 °C to 190 °C and mould temperatures of 20 °C to 40 °C are practical for unfilled or lightly filled parts; the clamp force is calculated from projected area and cavity pressure, with no universal tonnage applicable because part wall thickness, gate freeze-off time, and runner balance dominate pressure loss. The material is usually processed on a reciprocating-screw injection moulding machine with a screw L/D ratio of 20:1 to 24:1, compression ratio of 2.5:1 to 3.0:1, and a short nozzle to reduce heat history. Thin walls below 1.5 mm commonly trigger short shots unless gate size and vent depth are increased; published data for this specific configuration is limited, so mould-filling simulation should be calibrated with spiral-flow tests under ISO 294-1:2017 conditions. Pre-drying is not required unless ambient relative humidity exceeds 60 %; if drying is required, a desiccant dryer at 60 °C to 70 °C for 2 h to 4 h is used. Terminal parts include appliance feet, anti-vibration pads, sealing plugs, cable accessory boots, and bump stops for industrial equipment. Regulatory benchmarks depend on the article: food-contact uses fall under 21 CFR 177.1350, toy-like articles require EN 71-3:2019 screening, and general electrical or electronic parts are subject to RoHS 2011/65/EU Annex II.
Additive masterbatch production converts EVA 7470K into a lower-melting carrier resin with stronger affinity to polar pigments, flame retardants, and processing aids than LDPE, which improves dispersion in subsequent polyolefin dilution without requiring high carrier ratios. Typical carrier loadings in industrial masterbatch ranges place EVA 7470K at 40 wt% to 60 wt%, the active additive at 20 wt% to 40 wt%, and a wax dispersant at 5 wt% to 10 wt%. The manufacturing route uses a co-rotating twin-screw extruder with L/D ratio of 28:1 to 40:1 and barrel temperatures from 130 °C to 160 °C; the melt is strand-pelletized or underwater-pelletized depending on additive melting point and dustiness. The main processing bottleneck is feed port bridging when high-aspect-ratio additives are used; side-feeding after the polymer melt seal is required above 35 wt% mineral filler to avoid screw block and torque spikes. The carrier’s 26 wt% vinyl acetate content lowers melt temperature compared with LDPE but limits maximum drying temperature to 60 °C if the masterbatch contains hydrolytically sensitive additives. Terminal products include pigment masterbatch for polyolefin film, flame-retardant masterbatch for cable jacketing, and chemical blowing agent masterbatch for foam. Compliance for this conversion stage is anchored to REACH EC 1907/2006 registration and RoHS 2011/65/EU Annex II; downstream converters remain responsible for final article testing.
| Application scenario | Standard designation | Method or clause | Property assessed |
|---|---|---|---|
| Crosslinked footwear foam | ASTM D395-18 | Method B | Compression set |
| Crosslinked footwear foam | ISO 17707:2018 | Flexing resistance | Midsection flex fatigue |
| Hot-melt packaging adhesive | 21 CFR 175.105 | Indirect food-contact adhesives | Regulatory suitability |
| HFFR cable compound | IEC 60332-1-2:2004 | Vertical flame propagation | Flame retardance |
| HFFR cable compound | IEC 60754-1:2011 | Halogen acid gas content | Halogen-free verification |
| Foam mat and child-play tile | EN 71-3:2019 | Migration of elements | Safety for childcare articles |
| Injection-moulded soft part | 21 CFR 177.1350 | Ethylene-vinyl acetate copolymer | Food-contact suitability |
| Additive masterbatch | RoHS 2011/65/EU | Annex II | Restricted substance screening |
Competitive Formosa Taisox EVA 7470K prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615380400285 or mail to sales2@liwei-chem.com.
We will respond to you as soon as possible.
Tel: +8615380400285
Email: sales2@liwei-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Formosa Taisox EVA 7470K is an ethylene-vinyl acetate copolymer resin supplied in pellet form for extrusion lamination, cast film, thin-gauge sealant webs, foam processing, and injection molding of flexible components. The product is not an LDPE homopolymer; the 7470-series designation does not encode the vinyl acetate content, and specification must be read from the lot certificate or the published datasheet. Standard values reported for 7470K include a vinyl acetate monomer content of 26 wt%, a melt flow index of 4.0 g/10 min at 190°C under 2.16 kg load in accordance with ASTM D1238, and a solid density of 0.951 g/cm³ by ASTM D1505. The presence of 26 wt% vinyl acetate reduces crystallinity relative to lower-VA Taisox grades, lowers the cooling-induced crystalline plateau, raises low-temperature flexibility, and shifts heat-seal initiation downward in multilayer packaging structures. In comparison with ethylene-vinyl acetate grades containing 18 wt% or 21 wt% VA, 7470K exhibits greater polarity and lower secant modulus, which is exploited in foil adhesion layers and foam-cell stabilization during gas expansion. The product's stabilization package is configured for conventional melt processing, but the specific antioxidant system and residual vinyl acetate monomer level must be verified against the certificate of analysis for each lot.
Ethylene-vinyl acetate copolymers crystallize through the polyethylene sequences; each inserted vinyl acetate comonomer limits the fold length in the orthorhombic lattice. At 26 wt% VA, differential scanning calorimetry according to ASTM D3418 produces a broad endotherm with a typical peak between 75°C and 80°C, while a comparable film grade at 18 wt% VA normally peaks between 85°C and 92°C. The lower crystalline weight fraction reduces the Vicat softening point and shifts deformation behavior toward elastomeric response under load. Heat-seal initiation is not a single melting point; it is the temperature at which the resin flows sufficiently under jaw pressure to wet the opposing substrate. In extrusion lamination trials, the seal initiation of 7470K is expected to fall 5°C to 10°C lower than an 18 wt% VA grade at equivalent melt index and film thickness. Hot-tack strength, measured by ASTM F1921, and ultimate T-peel adhesion to foil, measured by ASTM D1876, depend on both substrate surface energy and chill-roll quench rate. The greater polarity of vinyl acetate also improves the wetting of aluminium foil whose surface has been corona-treated above 42 dyn/cm or chemically etched. This property shift is not monotonic across all applications; higher VA content increases blocking tendency in wound film and demands anti-block masterbatch addition in thin-gauge cast film.
Processability of 7470K is governed by the shear-thinning character of the branched copolymer. A melt flow index of 4.0 g/10 min by ASTM D1238 is not a complete viscosity curve; capillary rheometry at 190°C with an L/D 30:1 die is required to determine pressure-flow behavior at shear rates between 100 s⁻¹ and 1,000 s⁻¹. On a 90 mm single-screw extruder with 30:1 L/D and a barrier screw, typical extrusion lamination throughputs of 150 kg/h to 250 kg/h can be processed with a melt temperature of 170°C to 190°C. Melt temperature overshoot beyond 200°C is a critical boundary for high-VA EVA because deacetylation and oxidative gel formation accelerate with residence time; gel defects larger than 0.3 mm in cast film can be counted by ISO 18553. Conversely, melt temperatures below 170°C increase backpressure and may destabilize the melt curtain in extrusion lamination, causing neck-in variation at the die lip. Published data for 7470K-specific screw speed and pressure profiles are limited; start-up must therefore use the lot-specific melt index and viscosity curve rather than generic EVA settings. When the resin is processed on a coextrusion line for sealant films, the extruder profile should provide a flat temperature plateau from the metering zone to the die, with die gaps set at 0.5 mm to 0.8 mm for a 60 µm to 100 µm final film. High-VA grades also show a narrower processing window than LDPE homopolymer; the difference between onset of stable flow and degradation temperature is approximately 30°C or less in some equipment configurations, making barrel-zone calibration critical.
In extrusion lamination, 7470K is extruded as a molten web onto paper, aluminium foil, oriented polypropylene, or polyethylene terephthalate. Typical coating weights are between 15 g/m² and 25 g/m², with the substrate pre-treated to a surface energy of at least 42 dyn/cm for polyolefins and 50 dyn/cm for polyester films. Adhesion of the EVA web to aluminium foil is influenced by melting temperature, air gap, and chill-roll quench; T-peel adhesion by ASTM D1876 commonly shows cohesive failure in the EVA layer rather than interfacial delamination when the melt reaches the foil at 190°C and is immediately quenched to 15°C to 20°C. In coextruded sealant films, 7470K may serve as the inner sealing layer at 10 µm to 20 µm thickness. Heat-seal windows of 85°C to 110°C at 0.3 s dwell and 0.27 MPa jaw pressure are typical for high-VA EVA sealants; however, the final window must be validated on the target packaging machine because film gauge and substrate heat capacity shift the interface temperature. The lower melting range of 7470K compared with 18 wt% VA EVA allows sealing through thicker films at reduced jaw setpoints, but the wound roll after cooling exhibits higher blocking tendency and requires anti-block agent levels of 1,000 ppm to 3,000 ppm depending on gauge and storage temperature.
The differentiation between 7470K and lower-VA ethylene copolymers is expressed primarily in thermal response, stiffness, and surface polarity. The following representative values are drawn from polymer-class data and typical published datasheets; they are not a substitute for a commercial lot certificate.
| Property | 7470K (26 wt% VA) | 18 wt% VA film-grade EVA | Test reference |
|---|---|---|---|
| Vinyl acetate monomer content | 26 wt% | 18 wt% | ISO 8985 |
| Melt flow index at 190°C/2.16 kg | 4.0 g/10 min | 2.0 to 8.0 g/10 min | ASTM D1238 |
| Density | 0.951 g/cm³ | 0.940 g/cm³ | ASTM D1505 |
| Peak melting range by DSC | 75°C to 80°C | 85°C to 92°C | ASTM D3418 |
| Seal initiation relative | lower by 5°C to 10°C | higher | ASTM F2029 |
| Relative adhesion to aluminium foil | higher | lower | ASTM D1876 |
The table illustrates that 7470K is selected when the converting line requires lower seal initiation and greater foil wetting; it is not the automatic choice for high-stiffness films or for applications requiring dimensional stability at elevated ambient temperature because the lower crystallinity reduces modulus and increases blocking tendency. Lower-VA Taisox grades retain more polyethylene-like hardness and better gauge control during high-speed blown-film conversion.
In footwear sole expansion and injection-molded EVA foam, 7470K is generally mixed with an azodicarbonamide-based blowing agent at 1.5 phr to 2.5 phr and a peroxide crosslinking agent at 0.8 phr to 1.2 phr in a kneader or internal mixer. The compound is then moulded on a reciprocating-screw injection moulding machine with clamp force of 150 t to 250 t and an L/D 20:1 to 22:1 screw. Barrel temperature profile is kept at 130°C to 170°C in the feed and compression zones and 170°C to 190°C at the nozzle, with mold temperature held at 30°C to 45°C. Foam density after expansion typically ranges from 0.20 g/cm³ to 0.35 g/cm³ for midsoles; cure time and blowing agent decomposition must be balanced to avoid premature gas loss. The crosslinking reaction follows peroxide initiation kinetics; amines and certain phenolic antioxidant systems can interfere with free-radical cure, so additive packages must be screened before production. Hardness of the foamed midsole is measured by ISO 868 Shore C and generally falls between 45 and 55 for midsole grades; tensile properties are measured by ISO 37. Published data for 7470K-specific foaming rheometry is limited, so initial shot size and mold prefill studies are required on the production machine.
Regulatory compliance for food-contact use is site-specific. In the United States, ethylene-vinyl acetate copolymers may fall under 21 CFR 177.1350 if the compositional and extractives conditions are met. EU food-contact evaluation follows the general requirements of EU 10/2011, and the finished article must be migration-tested for the intended food simulant. REACH and RoHS compliance for packaging or electrical applications should be confirmed through the material safety data sheet and the producer's declaration. The product does not contain intentionally added phthalate plasticizers, but users must verify against the lot-specific documentation.
Regrind of 7470K edge trim and start-up scrap can be re-introduced into extrusion lamination and cast film processes only after size reduction and dedusting. In cast film, the recommended post-industrial regrind content does not exceed 20 wt%, because degraded vinyl acetate sequences increase gel counts and reduce tear strength. The gel threshold defined by ISO 18553 should be monitored; accumulated gels above 0.3 mm diameter can create visible fish eyes in thin sealant film. The resin should not be compounded with strongly alkaline additives or acid-releasing masterbatches, because deacetylation at melt temperatures above 200°C releases acetic acid and accelerates corrosion in downstream quench rolls and winders. Peroxide-cured foam formulations should avoid amine-based heat stabilizers that scavenge free radicals and reduce crosslink density. When storage conditions exceed 60% relative humidity, surface moisture on pellet surfaces can be removed by pre-drying at 60°C to 70°C for 2 h to 4 h in a desiccant dryer; the copolymer is not hygroscopic, so the drying load is low. Unopened bags stored at 25°C and 50% relative humidity are typically assigned a shelf life of 12 months from the production date, after which melt flow and antioxidant content should be re-verified by ASTM D1238 and oxidative induction time testing.
