| HS Code | 858340 |
| Chemical Name | Ethylene-Vinyl Alcohol Copolymer |
| Ethylene Content | 29 mol% |
| Density | 1.21 g/cm³ |
| Melting Point | 188°C |
| Glass Transition Temperature | 58°C |
| Melt Flow Rate | 1.5 g/10 min (190°C, 2.16 kg) |
| Tensile Strength | 80 MPa |
| Elongation At Break | 280% |
| Flexural Modulus | 2300 MPa |
| Oxygen Transmission Rate | 0.02 cm³·mm/(m²·day·atm) at 20°C, 65% RH |
As an accredited EVOH EV-2951 V/F factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | EVOH EV-2951 V/F resin pellets are supplied in 25 kg moisture-proof sealed bags, palletized and stretch-wrapped for safe transport. |
| Container Loading (20′ FCL) | 20′ FCL shipment of EVOH EV-2951 V/F resin, packed on pallets with protective wrapping, secured for safe transport. |
| Shipping | EVOH EV-2951 V/F is a non-hazardous ethylene vinyl alcohol copolymer resin shipped in sealed moisture-proof bags. Protect from water, humidity, and direct sunlight. Transport in clean, dry containers at ambient temperatures, avoiding excessive heat or compression. Handle gently to prevent bag damage and maintain product purity. |
| Storage | Store EVOH EV-2951 V/F in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and ignition sources. Keep the original container tightly sealed to prevent moisture absorption and contamination. Avoid exposure to excessive humidity and temperatures above 30°C. Maintain adequate storage stability and follow manufacturer’s safety guidelines. |
| Shelf Life | Shelf life is typically 2–5 years when stored sealed, dry, and away from direct sunlight or extreme heat. |
In five-layer blown-film coextrusion for processed meat and cheese packaging, EV-2951 V/F is placed as the discrete core barrier layer at 4–7 wt% of total film mass, corresponding to a core caliper of 3–8 µm inside a 50–120 µm PE/tie/EVOH/tie/PE structure. The structure is designed for direct food contact under EU 10/2011 Annex I, with overall migration tested according to EN 1186-1, and the resin must be covered by an FDA food-contact notification or a clearing regulation under 21 CFR Part 177; oxygen barrier is measured per ASTM D3985, typically falling below 1.0 cm³/(m²·day·0.21 atm) at 23°C and 0% RH. Drying before extrusion is mandatory at 80–100°C in a desiccant dryer with dew point -40°C or lower until residual moisture is ≤0.01 wt%; moisture in the feed throat above this threshold generates gel specks and pinholes. Extrusion equipment is specified with barrier screws of 24:1–30:1 L/D and compression ratio 2.5:1–3.0:1; barrel zones are held at 180–220°C, die zones at 220–230°C, and melt temperature is kept below 240°C, beyond which gelling and black specks accelerate. Residence time at melt temperature is held below 8 min because gel accumulation on the die lip forces line stops and film defects. Downstream conversion includes corona treatment of the outer polyethylene skin, flexographic or gravure printing, and subsequent lamination to polyester or oriented polyamide; the EVOH core is not exposed to direct ink or adhesive contact. Terminal finished goods include modified-atmosphere packaging pouches, vacuum skin packages, and flow-wrap films for sliced processed meat, cheese, and snack products.
Sheet coextrusion trials for retortable PP/EVOH/PP tray stock require EV-2951 V/F to be metered into the core at 3–6 wt% of total sheet mass, with a nominal core layer of 2–5% of sheet thickness, because a thinner core produces variable oxygen barrier at tray corners and a thicker core raises scrap recovery costs. The food-contact compliance framework is identical to the flexible film route: EU 10/2011 Annex I overall migration testing under EN 1186-1 and oxygen transmission measurement under ASTM D3985. In a typical coextrusion sheet line, polypropylene skins and maleic-anhydride-modified tie layers are combined in a feedblock feeding a flat die of 1,200–1,800 mm width; EVOH melt temperature is held at 210°C while PP melt temperature is 230–240°C. The viscosity mismatch between EVOH and PP causes layer encapsulation when the feedblock selector plug is not matched to the resin viscosity, a failure observed on production lines as an asymmetric core layer drifting toward one skin. Sheet surface temperature during plug-assisted thermoforming is maintained at 160–180°C; at draw ratios above 5:1, the corner barrier layer can thin below 12 µm, and the formed tray fails oxygen barrier requirements. Regrind of thermoforming skeletal scrap is limited to 30–40 wt% in the regrind layer because degraded EVOH particles in the scrap raise gel specks in the sheet. Terminal products are retortable ready-meal trays, MAP trays for fresh pasta, and rigid cups for flavored coffee capsules; all require mineral-filled PP skins to reduce post-thermoforming warpage.
During accumulator-head coextrusion of six-layer HDPE/adhesive/EVOH/adhesive/regrind/HDPE parisons, EV-2951 V/F is inserted at 1.5–3.0 wt% of the total wall mass, generally a core thickness of 100–180 µm in a 6–10 mm closed mold wall. The function is to satisfy evaporative hydrocarbon emission limits under 40 CFR 86.1811 and California LEV III requirements, with permeation measured by gravimetric or coulometric methods equivalent to ASTM D3985 adapted to fuel contact. The EVOH melt stream is maintained at 205–225°C, while HDPE runs at 220–240°C; die head accumulators must be programmed to push more parison material into the pinch-off corners, because EVOH thickness at the weld seam can drop below 50 µm and create a hydrocarbon permeation channel. Regrind from parison flash and trim is introduced into a separate regrind layer at 30–50 wt% of the wall; field data from multilayer die trials show that exceeding 50 wt% regrind raises the viscosity of the outer HDPE layers and distorts the barrier core. Process limitations are significant: EVOH must be protected from moisture before extrusion with the same ≤0.01 wt% residual moisture specification, and the resin is suitable only for gasoline and diesel systems with methanol content ≤5 vol%; published data for the specific configuration with higher methanol flex-fuel grades is limited. Terminal finished products are automotive fuel tanks for sedans, utility vehicles, and small off-road equipment, where the EVOH layer replaces fluorination or post-mold barrier treatments.
When aluminum foil is replaced in pharmaceutical unit-dose sachet and strip webs, EV-2951 V/F is coextruded as a core barrier layer at 5–10 wt% of the total web mass, with a thickness of 6–15 µm within an 80–120 µm PE/tie/EVOH/tie/PE or PP-compatible structure. Compliance is evaluated against Ph. Eur. 3.1.5 or USP 661.1 for plastic packaging materials, European Directive 2001/83/EC packaging components, and moisture vapor transmission testing under USP 671; oxygen transmission is tested under ASTM D3985. Processing is carried out on cast film or blown-film lines at EVOH melt temperatures of 200–220°C, followed by lamination to paper, polyester, or aluminum oxide-coated substrates with solvent-free adhesives. The EVOH layer is never printed or sealed directly; conversion requires polyolefin skin layers on both sides to protect the moisture-sensitive core from hygroscopic swelling. Terminal finished goods include powder dose sachets, transdermal patch pouch stock, diagnostic strip overwrap, and desiccant-containing pouches for moisture-sensitive oral solid dosage forms. Unlike aluminum-based structures, the transparent EVOH web does not provide zero moisture ingress; products requiring moisture protection below 0.1 g/(m²·day) water vapor transmission need desiccant additions or aluminum oxide overcoating.
In five-layer PEX-b pipe crosshead coextrusion, EV-2951 V/F is inserted as the oxygen diffusion barrier between two tie layers and two polyethylene skins at 0.05–0.20 mm thickness in a 2.0 mm pipe wall, representing 2.5–10% of wall thickness. The controlling standard is ISO 17455 for oxygen permeability of thermoplastic pipe walls, with hydronic system design following EN 1264-4; the oxygen diffusion criterion is generally ≤0.1 g/(m³·d) at 40°C. Processing on a five-layer crosshead die with vacuum calibration maintains EVOH melt temperature at 190–210°C, below the 240°C degradation threshold, while polyethylene skins are extruded at 200–230°C. After coextrusion, the pipe is crosslinked by silane grafting and moisture curing in a water bath at 80°C; EVOH layer thickness must be uniform to within ±0.01 mm to avoid stress cracking during pipe bending. Field failures on underfloor heating lines occur when the EVOH core exceeds 0.20 mm and the pipe is coiled at temperatures below 5°C, causing radial cracks at the tie-layer interface. Terminal finished products are underfloor heating pipes, radiator connection pipes, and distribution pipes for low-temperature hot-water systems, where the barrier layer prevents oxygen ingress that would corrode ferrous pumps and heat exchangers.
| Test method | Measured property | Acceptance criterion |
|---|---|---|
| ISO 17455 | oxygen permeability through pipe wall | ≤0.1 g/(m³·d) at 40°C |
| ASTM D3985 | oxygen transmission rate of film | ≤1.0 cm³/(m²·day·0.21 atm) |
| EN 1264-4 | hydronic system design | oxygen barrier pipe class |
Extrusion blow moulding of six-layer HDPE/regrind/tie/EVOH/tie/HDPE bottles for solvent-based agrochemicals meters EV-2951 V/F at 1.5–3.0 wt% of bottle mass, yielding an EVOH core of 80–150 µm in a typical 1 L, 5 L, or 20 L container wall. The package must meet UN Model Regulations Chapter 6.1 and ADR/RID dangerous goods packaging requirements, including drop tests and leakproofness tests under UN 6.1.5. EVOH melt temperature is controlled at 200–220°C; when the melt stream falls below 195°C, pinch-off weld strength drops because EVOH crystallizes before HDPE and the weld seam retains a brittle core layer. Field inspection of failed containers shows delamination at the pinch-off line after drop tests at -18°C, indicating insufficient EVOH melt temperature or excessive regrind above 40 wt% in the regrind layer. The EVOH barrier is effective against oxygen and many nonpolar solvents, but the container is not specified for extended direct contact with high-pH aqueous formulations or concentrated methanol because the EVOH core can suffer hydrolysis and barrier loss; such formulations require compatibility testing before commercial specification. Terminal finished products are coextruded HDPE barrier bottles and jerry cans for solvent-based crop protection chemicals, adjuvants, and industrial service fluids where fluorination is undesirable.
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EVOH EV-2951 V/F is a film-grade ethylene-vinyl alcohol copolymer supplied in pellet form for coextruded barrier film, sheet, and thermoformed packaging. The resin is produced by saponification of an ethylene-vinyl acetate copolymer; the residual vinyl alcohol units form interchain hydrogen bonds that reduce free volume and restrict oxygen diffusion. Supplier documentation lists a nominal ethylene content of 29 mol% for this grade. Melt flow rate determined under ISO 1133-1:2022 at 190 °C with 2.16 kg piston load is typically 1.5–2.0 g/10 min. Density determined under ISO 1183-1:2019 at 23 °C is approximately 1.17 g/cm³. The V/F suffix is not uniformly defined in public supplier literature; it is associated with vacuum and food packaging film applications, but the lot-specific certificate of analysis remains the controlling specification. Published data for the EV-2951 V/F designation is limited; the following property ranges are typical for the corresponding ethylene content and should be verified against the incoming resin certificate.
Oxygen transmission rate of EVOH is inversely related to ethylene content at low relative humidity. For a 20 µm monolayer film at 20 °C and 0 % RH, a 29 mol% ethylene grade typically exhibits oxygen transmission below 0.5 cm³/(m²·day·atm) under ASTM D3985. At 65 % RH, the same film commonly shifts to 2–5 cm³/(m²·day·atm), because water vapour plasticises the vinyl alcohol segments and increases segmental mobility. By comparison, a 38 mol% ethylene EVOH reference shows a higher dry-state oxygen transmission of approximately 1.5–2.5 cm³/(m²·day·atm) but retains useful barrier at elevated humidity with values closer to 1.0–2.5 cm³/(m²·day·atm). The dry-state barrier advantage of EV-2951 V/F is therefore accompanied by greater moisture sensitivity. Designers compensate by positioning the EVOH layer behind a polyolefin skin and by selecting a five-layer or seven-layer structure in which the EVOH core is never in direct contact with liquid water.
The melting peak of a 29 mol% ethylene EVOH typically falls in the 183–191 °C range under ISO 11357-3. The crystalline fraction responsible for the melting peak contributes to stiffness and low oxygen permeability but also narrows the forming window in thermoforming. When the grade is compared with a 44 mol% ethylene EVOH, EV-2951 V/F provides a lower oxygen transmission rate under dry conditions but a higher modulus and greater sensitivity to stress whitening. The selection of EV-2951 V/F over higher-ethylene grades is therefore justified only when the package design controls moisture contact at the EVOH interface.
| Property | Test method | EV-2951 V/F (29 mol% ethylene) | 32 mol% EVOH reference | 38 mol% EVOH reference |
|---|---|---|---|---|
| Oxygen transmission rate, 20 µm, 20 °C, 0 % RH | ASTM D3985 | ≤0.5 cm³/(m²·day·atm) | 0.8–1.2 cm³/(m²·day·atm) | 1.5–2.5 cm³/(m²·day·atm) |
| Oxygen transmission rate, 20 µm, 20 °C, 65 % RH | ASTM D3985 | 2–5 cm³/(m²·day·atm) | 1.5–3.5 cm³/(m²·day·atm) | 1.0–2.5 cm³/(m²·day·atm) |
| Melting peak | ISO 11357-3 | 183–191 °C | 180–188 °C | 168–175 °C |
| Melt flow rate at 190 °C, 2.16 kg | ISO 1133-1:2022 | 1.5–2.0 g/10 min | 1.6–2.2 g/10 min | 3.0–5.0 g/10 min |
| Density at 23 °C | ISO 1183-1:2019 | 1.17 g/cm³ | 1.17 g/cm³ | 1.16 g/cm³ |
Melt processing of EVOH EV-2951 V/F requires a narrow temperature corridor. Production-scale single-screw extruders with L/D 24:1 to 30:1 and a barrier screw having compression ratio 3.0:1 to 3.5:1 are commonly used. A representative barrel profile on a 75 mm coextruder is hopper zone 180 °C, compression 200 °C, metering 215 °C, adapter 220 °C, and die 225 °C. Melt temperature should remain below 240 °C; prolonged metal-surface temperatures above 250 °C are associated with gel formation, black specks, and crosslinking of degraded vinyl alcohol units. At 210 °C and shear rate 100 s⁻¹, melt viscosity is typically in the 1,000–2,000 Pa·s range. Viscous heating in mixing sections therefore must be limited; low-shear Maddock or pineapple mixing elements are preferred over high-intensity kneading blocks.
The screw and barrel should be manufactured from corrosion-resistant bimetallic alloys because residual acetate groups and vinyl alcohol decomposition products are acidic. Purging after coextrusion is performed with low-melt-index polyethylene; purging with PVC, acetal, or halogenated compounds is incompatible with EVOH and causes rapid discolouration. On a three-layer blown-film line, die lip temperatures should not exceed 230 °C to avoid atmospheric oxidation at the land exit. Layer encapsulation of the EVOH stream is recommended to prevent melt-lip condensation from hydrolysing the polymer surface.
Resin handling prior to extrusion is the controlling variable for film appearance. EVOH absorbs atmospheric moisture rapidly; at 50 % RH, pellet surface moisture can exceed 0.4 wt% within 4 h. Drying in a desiccant dryer at 80 °C for 4–6 h with dew point below −40 °C reduces moisture to below 0.1 wt%. Extruder venting alone does not remove bound water; residual moisture hydrolyses the polymer backbone and lowers intrinsic viscosity. On blown-film lines, wet resin produces bubble instability, interlayer waviness, and gel defects detectable in 30 µm three-layer structures. Hopper blankets and closed conveying lines are used in high-humidity plants to prevent re-moisturising after drying. For cast film lines, a vacuum hopper loader with dried-air purge is sufficient only when the ambient floor dew point is below 5 °C; otherwise double-run drying is required.
Because EVOH is hydrophilic, the finished multilayer structure must place hydrophobic skins outside the EVOH core to retard moisture ingress. In a five-layer PE/tie/EVOH/tie/PE structure, the water vapour transmission rate of the outer polyethylene layers under ASTM F1249 controls the steady-state relative humidity at the EVOH interface. High-density polyethylene skins with thickness 25–40 µm reduce the interfacial RH more effectively than low-density polyethylene of equal thickness. When the interface RH exceeds 65 %, oxygen transmission rises non-linearly; the loss is reversible until the film is exposed to water above 40 °C for extended periods, after which secondary crystallinity may partially anneal and the barrier does not fully recover. In hot-fill or retort packaging, the structure should be evaluated after processing because oxygen transmission of the finished package may increase by an order of magnitude relative to the dry film. Package-level testing under ASTM F1307 at 23 °C and 50 % RH is required to establish shelf-life because monolayer film data cannot account for interfacial moisture distribution.
Adhesion between EVOH and polyolefins is generated by maleic anhydride grafted polyethylene or polypropylene tie resins. The anhydride groups react with residual hydroxyl units on the EVOH surface during melt contact to form ester linkages. Typical tie-layer coverage is 2–4 g/m² per interface in cast film and 3–5 g/m² in thermoforming sheet. Peel strength greater than 2 N/15 mm after 24 h conditioning under ASTM D1876 is generally required for form-fill-seal packaging. Low peel strength occurs when tie resin is overdiluted by adjacent polyolefin layers or when the EVOH melt temperature is below the activation temperature for anhydride reaction. In production, peel failures propagate during thermoforming at corners where the sheet undergoes draw ratios above 1.5:1. Coextruded structures should be designed with tie-layer thickness verified by cross-section microscopy to confirm layer continuity before trial production. Incompatible adhesive systems include ionomer-only tie formulations that lack anhydride functionality; these provide adequate sealing but fail under flexural stress at the EVOH interface.
EVOH EV-2951 V/F is used in vacuum packaging of processed meat and cheese where oxygen barrier under chilled distribution is the primary requirement. The packaging structure typically comprises PA/tie/EVOH/tie/PE or PP/tie/EVOH/tie/PP. Oxygen transmission of the finished pouch is measured under ASTM F1307 at 23 °C and 50 % RH; values below 1.0 cm³/(m²·day·atm) are common for thick structures. In modified-atmosphere packaging for fresh red meat, the EVOH barrier maintains headspace gas composition; however, the high RH at the meat surface may generate localised interfacial moisture and reduce barrier over shelf life. In retortable structures, EVOH is shielded by aluminium foil or a thick polypropylene layer because saturated steam at 121 °C collapses barrier performance unless the package is stress-relieved. On vertical form-fill-seal equipment, the seal initiation temperature of the internal sealant layer, not the EVOH core, governs sealing speed; EVOH layers that extend into the seal area create hard seals and reduce production rates.
Regulatory compliance for EVOH EV-2951 V/F requires confirmation of food-contact status under the applicable regulatory framework. In the United States, the supplier food-contact statement normally references 21 CFR 177.1360; in the European Union, compliance is assessed under EU 10/2011 with overall migration limit 10 mg/dm² using EN 1186-1. Specific migration of ethylene and vinyl alcohol monomers should be verified against the positive list restrictions. REACH and RoHS declarations are supplier-specific; the grade is generally classified as a non-hazardous polymer article under current EU classification but users must confirm with the safety data sheet.
| Framework | Reference | Requirement |
|---|---|---|
| United States food contact | 21 CFR 177.1360 | Supplier confirmation that the resin is covered as an ethylene-vinyl alcohol copolymer food-contact substance |
| European Union plastic food-contact material | EU 10/2011 | Overall migration limit 10 mg/dm² by EN 1186-1 |
| Specific migration | EN 13130-1 | Monomer-specific migration must not exceed positive list limits |
| REACH | EC 1907/2006 | Article exemption confirmation per safety data sheet |
| RoHS | 2011/65/EU | Restricted heavy metals below 0.1 wt% except cadmium 0.01 wt% |
In comparison with PVDC and MXD6, EV-2951 V/F offers lower dry-state oxygen transmission but higher moisture sensitivity. PVDC provides more humidity-independent oxygen barrier and MXD6 offers better retort resistance but higher dry-state oxygen transmission. Selection over these materials is justified when low oxygen permeability at 20 °C and 0 % RH is the primary requirement and package design controls moisture contact. The grade should not be processed with amine-based additives or metallic stearates that catalyse vinyl alcohol dehydration at processing temperatures. Avoid direct contact with high-pH aqueous media because alkaline conditions accelerate saponification and surface hazing in the finished package.
