| HS Code | 315313 |
| Product Name | SINOPEC EVA 4F2 |
| Resin Type | Ethylene-Vinyl Acetate (EVA) Copolymer |
| Vinyl Acetate Content | 14 wt% |
| Melt Flow Rate 190 C 2 16kg | 2.0 g/10min |
| Density | 0.935 g/cm³ |
| Melting Point | 70°C |
| Vicat Softening Temperature | 62°C |
| Tensile Strength | 16 MPa |
| Elongation At Break | 800% |
| Shore A Hardness | 94 |
| Brittleness Temperature | -70°C |
| Crystallinity | Low |
As an accredited SINOPEC EVA 4F2 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SINOPEC EVA 4F2 is supplied in 25 kg polyethylene-lined woven bags, palletized and wrapped for safe transport. |
| Container Loading (20′ FCL) | Container Loading (20′ FCL): SINOPEC EVA 4F2, packed in 25kg bags, palletized and safely stowed in a 20-foot container for export. |
| Shipping | SINOPEC EVA 4F2 is shipped as solid pellets in moisture-proof woven or kraft bags, or in bulk containers. Ensure dry, ventilated conditions, avoiding direct sunlight and high temperatures. Non-hazardous, but handle with care to prevent contamination or bag damage during transport and storage. |
| Storage | Store SINOPEC EVA 4F2 in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and open flames. Keep containers sealed to prevent moisture absorption and contamination. Maintain temperatures below 30°C, avoid excessive stacking or pressure, and protect from mechanical damage. Use within the manufacturer’s recommended shelf life for optimal performance. |
| Shelf Life | SINOPEC EVA 4F2 has a shelf life of typically two years when stored in a cool, dry, well-ventilated area. |
The application scope for SINOPEC EVA 4F2 is constrained to downstream processes in which ethylene-vinyl acetate copolymers with nominal melt flow rate near 2.0 g/10 min at 190 °C/2.16 kg are used as melt-processable resins or blend components. All addition ratios are expressed as parts per hundred resin by weight unless otherwise indicated. Lot-specific values in the certificate of analysis for vinyl acetate content and melt flow rate must be used to adjust processing temperatures and formulations because shifts in comonomer content alter seal initiation, cell nucleation, melt elasticity, and adhesion to polar substrates.
In extrusion coating lines producing flexible laminates for food and pharmaceutical packaging, SINOPEC EVA 4F2 is deployed as the sealant or tie layer because the comonomer improves adhesion to aluminium foil, paperboard and corona-treated polyethylene terephthalate compared with unmodified LDPE. A single-layer sealant web typically contains 80–100 wt% EVA 4F2, 10–20 wt% LDPE for neck-in control, 0.05–0.10 phr hindered phenolic antioxidant, and 0.05–0.20 phr slip/anti-block concentrate; when EVA 4F2 is used as a skin layer on a coextruded structure, the layer may comprise 20–40% of total coating weight. Food-contact compliance is evaluated under FDA 21 CFR 177.1360(a) and EU 10/2011, with overall migration limits tested per EN 1186-2:2022; for the Chinese market, GB 9685-2016 governs additive loading. On a typical extrusion coating line, melt temperature at the die lip is maintained at 280–320 °C, the air gap is set to 100–250 mm, and the chill roll is held at 15–25 °C; line speeds of 80–300 m/min are attainable when substrate tension and back-pressure are stable. Neck-in measured at 100 m/min on a 1,000 mm slot die is typically 25–50 mm per side depending on air gap and melt temperature; narrowing the die gap below 0.5 mm increases melt shear and can reduce adhesion to foil. Corona treatment at 38–50 mN/m is applied in-line before winding to raise surface energy above 40 mN/m for lamination. Terminal products include paperboard carton liners, aluminium foil laminates for sachets, medical device pouch seal layers, and extrusion-coated nonwoven packaging. Pre-drying at 60–70 °C for 2–4 h is required only when storage humidity exceeds 60% RH; otherwise, retained moisture can generate micro-voids at the die exit and reduce seal integrity.
| Requirement | Standard/clause | Target condition |
|---|---|---|
| Food-contact resin identity | FDA 21 CFR 177.1360(a) | Ethylene-vinyl acetate copolymer conforming to specified extractive limits |
| EU food-contact compliance | EU 10/2011 | Overall migration below 10 mg/dm² according to EN 1186-2:2022 |
| Chinese additive compliance | GB 9685-2016 | Additive loading within positive list for food-contact materials |
| Surface energy after treatment | ISO 8296:2003 | ≥40 mN/m for lamination adhesion |
For polyolefin masterbatch production, EVA 4F2 functions as a carrier resin where its melt viscosity and comonomer content improve pigment wetting and filler dispersion compared with neat LDPE. A representative colour concentrate uses 30–70 wt% EVA 4F2, 20–50 wt% organic or inorganic pigment, 1–5 wt% fatty acid ester dispersant, and 0–20 wt% mineral filler; letdown ratios in finished polyolefin film or moulding compounds typically range from 2% to 8%. The 30 wt% carrier level is preferred for high-surface-area carbon black concentrates, while 70 wt% carrier is used for difficult-to-disperse organic pigments to reduce sieve residue and pressure-rise variation. Compliance for masterbatch carriers is typically demonstrated under ISO 9001:2015 process quality, REACH (EC) No 1907/2006, and, where relevant for electrical end uses, RoHS 2011/65/EU; melt flow rate is checked by ISO 1133-1:2022. Compounding is performed on a co-rotating twin-screw extruder with L/D ratio of 40:1 to 48:1, barrel temperatures of 130–170 °C, screw speed 300–600 rpm, and pelletiser water bath at 10–20 °C. Melt temperature at the die plate should not exceed 180 °C, and residence time above 200 °C should be kept below 30 s to avoid acetic acid evolution from the copolymer and subsequent screw corrosion. Finished product types include colour masterbatches for LDPE/LLDPE blown film, process-aid concentrates, and filler concentrates for injection-moulded housewares. Operational boundary: this carrier is not recommended as the sole carrier for PET, PC or PA masterbatches because melt-phase immiscibility and viscosity mismatch produce surface delamination and poor pigment distribution; for those polymer systems, compatibility-grade carriers are required.
Closed-cell sheet foams based on EVA 4F2 are produced by chemical blowing and peroxide crosslinking. The processing conflict is that peroxide crosslinking and blowing agent decomposition overlap; if the crosslink density rises too early, cell walls rupture before full expansion, while insufficient crosslinking causes melt collapse. Typical batch formulations use 100 phr EVA 4F2, 1.5–5.0 phr azodicarbonamide, 0.6–1.2 phr dicumyl peroxide, 1.0–2.5 phr zinc oxide, 0.3–1.0 phr stearic acid, and 0–30 phr calcium carbonate or talc. The compound is mixed on a two-roll mill at 95–110 °C, sheeted to the target preform thickness, and then press-foamed at 165–185 °C under 2–8 MPa for 6–12 min; free-foaming continuous ovens can be used at 170–190 °C when expanded sheet is preferred. Azodicarbonamide decomposition in this system initiates near 160 °C, and dicumyl peroxide half-life is approximately 1 min at 171 °C, so the curing press must provide uniform heat transfer to avoid density variation greater than ±10% across the sheet. Compliance is assessed by ISO 7214-2:2012 for compression set and density, ASTM D3575-20 for olefin foam mechanical properties, and REACH for blowing agent residues. End products include sports mats, protective padding, flotation boards, anti-fatigue mats, and packaging cushioning; for footwear midsole constructions requiring compression-deflection below 150 kPa at 25% strain, blending with a higher-vinyl-acetate EVA is required because low-comonomer lots produce stiffer foam. If the EVA 4F2 lot is at the low end of the vinyl acetate range, skin hardness above Shore C 55 should be expected, which limits use in soft-touch goods but is acceptable for industrial mats and protective panels.
| Target density | EVA 4F2 (phr) | Azodicarbonamide (phr) | Dicumyl peroxide (phr) | Zinc oxide (phr) | Filler (phr) |
|---|---|---|---|---|---|
| 120–150 kg/m³ | 100 | 4.0–5.0 | 0.8–1.0 | 1.5–2.0 | 0–5 |
| 200–250 kg/m³ | 100 | 2.0–3.0 | 0.7–0.9 | 1.0–2.0 | 10–20 |
| 300–400 kg/m³ | 100 | 1.0–1.8 | 0.6–0.8 | 1.0–1.5 | 20–30 |
For injection moulding of semi-flexible articles, EVA 4F2 is processed only after the lot melt flow rate is verified by ISO 1133-1:2022; a melt flow rate near 2.0 g/10 min at 190 °C/2.16 kg indicates that thin-wall filling requires higher injection pressure than higher-MI grades but produces lower warpage and better environmental stress-crack resistance. A typical moulding formulation contains 100 phr EVA 4F2, 0.05–0.20 phr hindered phenolic antioxidant, 0.05–0.30 phr nucleating agent, and 0.05–0.15 phr slip agent; where colour is required, a polyolefin masterbatch is added at 2–6 wt%. Process parameters on a reciprocating-screw injection moulding machine with L/D ratio of 20:1–24:1 include melt temperature 160–200 °C, mould temperature 20–40 °C, injection pressure 60–100 MPa, holding pressure 40–60 MPa, and back pressure 0.5–1.5 MPa. Clamping force for a 4-cavity household container mould with projected area of 400 cm² is typically 1,200–1,600 kN, and shrinkage after 24 h is 1.6–2.4% in the flow direction measured by ISO 294-4:2018. Compliance for toys and childcare articles is established under EN 71-3:2019+A1:2021 for migration of certain elements, REACH Annex XVII, and FDA 21 CFR 177.1360 where the article may contact dry food. Terminal product types include flexible hinges, protective corner mouldings, household storage containers, tool grips, and semi-rigid caps. The main processing boundary is the high viscosity of the grade: if peak cavity pressure remains below 30 MPa, short shots occur in ribs with thickness below 1.2 mm; moulds should be gated at the thickest section and vented to avoid burn marks. For food-contact articles, the maximum use temperature should not exceed 60 °C for repeatedly reheated containers unless food simulant testing demonstrates compliance under the intended worst-case contact ratio.
In blown-film extrusion, EVA 4F2 is generally not run at 100% in monolayer structures because the low melt index and higher melt elasticity reduce bubble stability at high blow-up ratios; instead, it is let down at 15–35 wt% into LDPE or LLDPE to improve heat-seal initiation and dart impact. A typical blend consists of 65–85 wt% LDPE or LLDPE, 15–35 wt% EVA 4F2, and 2–5 wt% anti-block/slip masterbatch. For food-grade frozen-food bags, the blend must comply with FDA 21 CFR 177.1360 and EU 10/2011. Mechanical performance is assessed by ASTM D1709-22 dart drop, ASTM D1922-21 Elmendorf tear, and ISO 527-3:2018 tensile properties; heat-seal strength is tested by ASTM F88/F88M-21. Process conditions on a monolayer blown-film line include die gap 1.2–2.4 mm, blow-up ratio 2.2:1–3.0:1, melt temperature 170–210 °C, and frost line height 4–8 die diameters; output of 80–200 kg/h is typical for a 90 mm extruder with 30:1 L/D. At 15 wt% addition, dart impact increases by 10–18% relative to the neat LDPE control when film thickness is 50 µm; at 35 wt% addition, seal initiation shifts 5–12 °C lower under ASTM F1921-20, but machine-direction tear may drop by 5–10% because the blend elongates less uniformly. Terminal films include frozen-food bags, industrial liners, agricultural tunnel film, and heavy-duty shipping sacks. Operational limitation: at addition levels above 35 wt%, the blend can exhibit reduced bubble stability and blocking; output should be reduced by 10–20% and the die gap opened to maintain a stable neck. The seal initiation shift is the primary reason for the blend, not tensile enhancement; film slip agents must be rebalanced because EVA increases the coefficient of friction at the sealant surface.
Flat-die sheet extrusion of EVA 4F2 is used for trays and inserts that must remain ductile at freezer temperatures and avoid stress whitening during forming. The sheet formulation may contain 70–100 wt% EVA 4F2 and 0–30 wt% LLDPE to lower sheet surface tack, with processing aid at 0.02–0.10 phr and antioxidant at 0.05–0.20 phr. Compliance for food contact is tested under FDA 21 CFR 177.1360 and EU 10/2011; mechanical quality control uses ISO 527-3:2018 tensile tests on die-direction and transverse-direction specimens. Extrusion is carried out on a single-screw sheet line with barrier screw and L/D 28:1–32:1, melt temperature 160–200 °C, flat die set at 180–210 °C, and three-roll stack temperature 40–70 °C; sheet thickness is typically controlled between 0.3 mm and 2.0 mm. For a 0.8 mm sheet, die gap is set to 1.0–1.2 mm, and line speed is adjusted to 5–15 m/min depending on roll-stack cooling capacity. Thermoforming follows at sheet surface temperatures of 90–120 °C using plug-assisted air pressure of 4–7 bar; plug temperature is held at 80–100 °C to prevent premature chilling. Terminal products include freezer trays, blister packs for hardware, dunnage trays, and low-temperature distribution inserts. The boundaries are process-specific: below 90 °C sheet temperature, corner cracking increases sharply, while above 120 °C the sheet can sag and produce web thinning beyond 30% of the initial gauge. Frozen-food trays formed from EVA 4F2 sheet are typically tested at -30 °C for drop resistance under ASTM D5276-19 or distribution test protocols derived from ISTA 3A; if the LLDPE blend exceeds 30 wt%, low-temperature ductility improves but the oxygen transmission rate rises, so barrier packaging structures require coextruded EVOH or aluminium laminates.
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SINOPEC EVA 4F2 is a low-vinyl acetate ethylene-vinyl acetate copolymer pellet grade positioned for film, lamination, and moderate-seal packaging structures where the processing behaviour of LDPE is retained while introducing measurable comonomer-derived toughness. Published technical data associated with the grade list a vinyl acetate comonomer content of 4.0 wt% determined by Fourier transform infrared spectroscopy and a melt mass-flow rate of 2.0 g/10 min when tested at 190 °C under a 2.16 kg load in accordance with ISO 1133-1:2022. Density is reported at 0.925 g/cm³ using ISO 1183-1:2019. These values place the grade below typical high-VA adhesive and foam grades and above standard LDPE film homopolymers in terms of chain irregularity and low-temperature crack resistance.
Because the vinyl acetate content is low, the copolymer retains a relatively sharp crystalline melt peak rather than the broad endotherm seen in high-VA EVA. Differential scanning calorimetry following ISO 11357-3:2018 typically gives a peak melting temperature near 106 °C, with a Vicat softening temperature of approximately 88 °C under Method A50 per ISO 306:2022. The tensile response, measured on compression-moulded plaques according to ISO 527-2:2021, is close to LDPE-like stiffness but with improved elongation; a representative yield stress of 9.0 MPa and elongation at break of 600 % are stated as typical values, not contractual minimums.
Table 1 consolidates representative data extracted from supplier technical documentation. Lot-specific certificates of analysis should govern final acceptance because specification limits may be broader than the listed values.
| Property | Typical value | Test method |
|---|---|---|
| Vinyl acetate content | 4.0 wt% | ASTM D5594-18a / ISO 8985:2022 |
| Melt mass-flow rate | 2.0 g/10 min | ISO 1133-1:2022, 190 °C, 2.16 kg |
| Density | 0.925 g/cm³ | ISO 1183-1:2019 |
| Melting peak | 106 °C | ISO 11357-3:2018 |
| Vicat softening point | 88 °C | ISO 306:2022 |
| Tensile yield stress | 9.0 MPa | ISO 527-2:2021 |
| Tensile elongation at break | 600 % | ISO 527-2:2021 |
These property anchors do not describe processability on a specific line. Film converters should verify melt temperature, back pressure, and melt curtain stability on the intended equipment because the processing window is sensitive to residence time rather than to MFR alone.
In blown film, the recommended melt path is constrained by the onset of acetate-elimination degradation. On single-screw extruders with L/D ≥ 25 and a screened barrier or Maddock mixing section, barrel temperatures from 160 °C to 190 °C and die-head temperatures from 180 °C to 210 °C are used. The melt temperature measured at the die lip should remain below 220 °C; excursions above this threshold accelerate liberation of acetic acid, promote gel formation, and corrode unprotected die surfaces. Hard chrome or electroless nickel plating on die lips and downstream idlers is specified on production lines where temperatures tend to drift.
Die gap settings between 0.8 mm and 1.2 mm are typical for LDPE-compatible film grades. Blow-up ratios are held at 2.0:1 to 3.0:1, and the frost line is maintained at 4 to 8 die diameters above the air ring. Higher blow-up ratios increase transverse direction orientation but may reduce bubble stability if the film enters the frost line with insufficient melt strength. Chilled-air air rings with single-lip or dual-lip control are used; internal bubble cooling is generally not required for film below 100 µm.
Residence time is a critical variable. On 90 mm single-screw lines with L/D 30, residence times above 6 min are avoided by reducing screw speed only within the gearbox’s allowed range. Purge using a low-MFR LDPE after shutdown and before long idle periods prevents stagnation in the adapter and screen changer. Continuous screen packs with 60/100/60 mesh configurations are used to keep back pressure in the range 10 MPa to 25 MPa without causing excessive shear heating.
For melt fracture control, the apparent shear viscosity of a 2.0 g/10 min low-VA EVA at 190 °C is typically reported in the range 300 Pa·s to 500 Pa·s at 10 s−1; published data for 4F2 specifically under capillary rheometry are limited. Die-land shear rates should be kept below 1,000 s−1 to avoid sharkskin surface defects in thin-gauge film.
Cast film and extrusion-lamination lines expose the material to a different heat history. In these processes, melt curtain stability is governed by the ratio of melt strength to gravitational draw; the 2.0 g/10 min MFR provides a wider draw window than a 0.5 g/10 min LDPE and a narrower window than a 7 g/10 min extrusion-coating grade. Typical melt temperatures for lamination are held between 250 °C and 290 °C; above 300 °C fuming increases rapidly, and the extraction duct must be designed for acetic acid. The substrate is pre-treated to a wetting tension of at least 38 mN/m before lamination; otherwise peel strength falls below the target. For paper and board lamination, in-line ozone treatment of the melt curtain is used to raise surface energy for peel-strength retention; generator output is scaled to web width and line speed rather than fixed.
Published data for specific multi-layer coextrusion structures containing 4F2 as a skin layer are limited. In the absence of line-specific validation, the material is introduced in blends with LDPE to modify adhesion without sacrificing bubble stability. Coextrusion feedblock and die design should avoid long interfacial residence time because degradation products at the EVA/LDPE interface can create optical defects.
Surface modification is required to control blocking because the polar ester functionality raises film-to-film friction compared with pure LDPE. Erucamide slip masterbatch is added at 500 ppm to 1500 ppm active slip, and synthetic silica antiblock is incorporated at 1000 ppm to 3000 ppm. Below these ranges, machinability on vertical form-fill-seal equipment degrades; above them, coefficient-of-friction values decline but haze increases and heat-seal strength decreases. The equilibrium coefficient of friction is measured after 48 h of aging at 23 °C per ISO 8295:2004 because erucamide migration is time-dependent.
High levels of slip should not be combined with corona treatment placed before the sealing operation, because surface oxidation retards slip bloom and creates non-uniform seal performance. The preferred sequence is to treat the film for print adhesion after sealing, or to use a segmented treatment lane. Excess silica above 3000 ppm can produce die-pressure fluctuations and accelerate screen-pack plugging on lines without gear pumps.
Compared with LDPE film resins, SINOPEC EVA 4F2 lowers the crystalline ordering and shifts the DSC melting peak downward by approximately 5 °C to 10 °C. The actual heat-seal initiation shift must be measured on the target packaging line because seal-bar pressure, dwell time, and film thickness dominate the result; hot-tack evaluations are conducted per ASTM F1921-20 where sealing reliability is critical.
Compared with a 14 wt% VA copolymer, the lower comonomer level retains more stiffness and dimensional stability but loses softness, tack, and low-temperature flexibility. At equivalent melt flow rate, the storage modulus at 23 °C for a 4 wt% VA EVA is reported in the range 100 MPa to 150 MPa when measured by dynamic mechanical analysis per ISO 6721-1:2019, while a 14 wt% VA grade falls below 80 MPa. These class-level comparisons explain the difference in handling stiffness; lot-specific dynamic mechanical analysis is necessary for design calculations. This distinction is critical in stretch film and frozen-food packaging; selecting 4F2 in place of a higher-VA grade reduces cling but improves score-line flex-crack resistance when combined with an appropriate LDPE fraction.
In applications where a specification demands vinyl acetate contents above 14 wt%, crosslinkable foam density below 40 kg/m³, or low-temperature seal initiation below 80 °C, SINOPEC EVA 4F2 is not an equivalent substitute. Its comonomer content is insufficient to deliver the necessary polarity for hot-melt adhesion to polar substrates or the softness required in EVA foam formulations. Replacement without requalification can produce seal leakage, lower peel values, and higher-density foam. Converters with existing screw and drying infrastructure for LDPE can trial the grade more efficiently than users coming from high-EVA processing, where lower process temperatures and vented barrels may not be present.
Before food-contact use, verification of compliance with EU 10/2011, FDA 21 CFR 177.1350, and any applicable national standards is required from the supplier certificate of conformance for the exact lot. The base resin is typically not formulated with intentionally added heavy metals, but additives and colour concentrates may alter the compliance status. REACH and RoHS compliance is compound-specific; no statement for the neat pellet can be extended to finished film, laminates, or coated papers without testing migration and total extractables.
Pellets should be stored in sealed containers below 40 °C and protected from direct sun. If bags are opened for more than 4 h under relative humidity above 60 %, surface moisture can produce voids in cast film and blown film bubble instability. Predrying at 60 °C to 70 °C for 2 h to 4 h using a desiccant dryer with a -30 °C dew point is specified before extrusion in humid environments.
On production-scale lines, the most commonly reported failure modes are melt curtains that tear at high draw ratios, bubble instability when the frost line is placed above 8 die diameters, and die-lip deposit formation after prolonged operation above 220 °C. These are managed by lowering die pressure, adjusting air-ring velocity, and increasing purge frequency rather than by altering the polymer specification. In lamination, inadequate substrate pretreatment is more often responsible for low peel strength than variation in the resin lot.
