| HS Code | 532975 |
| Product | EVOH EV-2904 V/F |
| Category | Ethylene Vinyl Alcohol (EVOH) Copolymer |
| Ethylene Content | 29 mol% |
| Density | 1.21 g/cm³ |
| Melt Flow Rate | 4 g/10 min (210°C, 2.16 kg) |
| Melting Point | 191°C |
| Glass Transition Temperature | 62°C |
| Tensile Strength | 80 MPa |
| Elongation At Break | 280% |
| Oxygen Transmission Rate | 0.05 cm³·mm/m²·day·atm (20°C, 65% RH) |
| Water Absorption | 10% (saturated at 23°C) |
As an accredited EVOH EV-2904 V/F factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | EVOH EV-2904 V/F is supplied in 25 kg sealed polyethylene-lined bags, with label, lot number, and safety data. |
| Container Loading (20′ FCL) | 20′ FCL container loading: EVOH EV-2904 V/F packaged in sealed bags on pallets, secured and protected from moisture. |
| Shipping | EVOH EV-2904 V/F is a non-hazardous ethylene vinyl alcohol copolymer resin. Ship in clean, dry containers or original packaging, protected from moisture and physical damage. Avoid extreme heat and direct sunlight. Not regulated as dangerous goods under IMO/IMDG, ADR, or IATA when shipped in standard conditions. |
| Storage | Store EVOH EV-2904 V/F in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep the original container tightly sealed to prevent moisture absorption and contamination. Avoid generating dust; maintain good housekeeping. Use within recommended shelf life, typically one year from delivery under proper storage conditions. |
| Shelf Life | Shelf life is typically 2 years from manufacture when stored unopened in original packaging under cool, dry conditions. |
In retortable flexible and semi-rigid packaging, EVOH EV-2904 V/F is utilized as a discrete core barrier layer inside five-layer or seven-layer coextruded films, where total oxygen diffusion flux is governed by the comparatively low oxygen permeability of the EVOH layer measured under ASTM D3985 at 23 °C and 50 % RH. A production-validated retort pouch structure consists of polypropylene outer layers of 20–30 µm, maleic anhydride-grafted polypropylene tie layers of 2–5 µm, and an EVOH EV-2904 V/F core layer of 4–12 µm, corresponding to a layer addition ratio of 5–15 % of total film thickness. The EVOH layer must be protected from retort moisture by the polypropylene skins because oxygen barrier loss accelerates when the EVOH layer reaches equilibrium above 75 % RH. Compliance is anchored to Commission Regulation (EU) No 10/2011, Annex I authorization and Annex II overall migration testing under retort conditions, and to FDA 21 CFR §177.1365 for ethylene-vinyl alcohol copolymers in food-contact articles. Downstream production employs a five-layer cast or blown coextrusion line with a dedicated EVOH extruder using an L/D 24:1 low-shear barrier screw, desiccant pre-drying at 80–85 °C for 4–6 h to a moisture content below 0.2 %, melt temperature at the feedblock of 210–230 °C, and residence time limits below 10 min to suppress thermal degradation. Terminal articles include retortable stand-up pouches for cooked meat and ready-to-eat rice bowls, wet pet food pouches, and high-barrier retort trays, where package headspace oxygen ingress must remain below the oxidative threshold of the packed food matrix.
Multilayer blow molded fuel system components incorporate EVOH EV-2904 V/F as an internal hydrocarbon barrier core between high-density polyethylene substrate layers and maleic anhydride-functionalized tie resin; the EVOH layer remains a continuous discrete layer at 1.5–3.0 % of total parison wall thickness, typically 30–80 µm in a 5–8 mm tank wall, rather than being compounded into the HDPE matrix. Compliance in North American light-duty vehicle fuel systems is evaluated under evaporative emission limits in EPA 40 CFR Part 1060 and corresponding CARB LEV III certification requirements. On production-scale six-layer accumulator-head blow molding machines, EVOH EV-2904 V/F is processed through a dedicated extruder at melt temperature 200–220 °C, while HDPE is processed at 220–240 °C; pre-drying at 80 °C for 4 h to below 0.2 % moisture is required. A known process failure mode occurs at the pinch-off weld where barrier layer thickness collapses, so parison programming is used to compensate by locally increasing the EVOH layer. Regrind containing EVOH is limited to approximately 30 % in the regrind layer to control melt pressure and gel formation. Published data for EV-2904 V/F in this specific automotive configuration is limited, and final structure approval remains subject to automaker material qualification. Terminal articles include multilayer HDPE fuel tanks for passenger cars, small off-road equipment, and marine fuel containers, where hydrocarbon permeation must remain below evaporative emission thresholds over the vehicle service life.
Vacuum insulation panel envelope films require a combination of oxygen barrier, moisture protection, and heat-seal integrity that is obtained by laminating an EVOH EV-2904 V/F core layer with outer polyamide or PET and inner polyethylene layers; the EVOH layer is typically 4–8 µm within a 60–100 µm total laminate, or 5–10 % of total film thickness. Gas transmission of the finished envelope is evaluated under ASTM D3985 for oxygen and ASTM F1249 for water vapor. The inner polyethylene sealing layer and an optional aluminum metallization prevent the EVOH from hydrating above 70 % RH, at which point oxygen barrier decline becomes measurable. Compliance is specified through ISO 16478-1 for vacuum insulation panel performance and EN 16012 for thermal insulation product evaluation. In production, the EVOH-containing film is produced on a cast coextrusion line and then adhesive-laminated to a metallized barrier web; envelope sealing is performed on a four-side vacuum-panel sealing machine at residual pressures of 0.5–5 mbar. Edge thinning over EVOH-containing fold lines is an observed failure mode, so seal geometry must maintain the polyethylene layer as the continuous sealing surface. Terminal products include vacuum insulation panels for pharmaceutical cold-chain containers, refrigerated truck panels, and building envelope insulation boards, where long-term gas permeation determines service life.
Extruded laminate tube bodies for oxygen-sensitive topical pharmaceuticals and high-viscosity cosmetic pastes use EVOH EV-2904 V/F as a buried barrier core between low-density polyethylene skin layers and tie resins, with the core layer occupying 15–35 µm of a 250–400 µm tube wall, or 6–14 % of total wall thickness. The EVOH layer is positioned closer to the outer wall in some structures to reduce flex-crack propagation into the barrier, while the inner polyethylene layer provides sealability and product compatibility. Compliance for pharmaceutical tubes is referenced to ISO 15378:2017 for primary packaging materials for medicinal products, while cosmetic packaging follows Regulation (EC) No 1223/2009; food-adjacent applications are evaluated under FDA 21 CFR §177.1365 and Commission Regulation (EU) No 10/2011. Production uses a five-layer tube-laminate extrusion line with a dedicated EVOH extruder maintained at 210–230 °C, with pre-drying at 85 °C for at least 4 h; the extruded web is cut into tube bodies, welded longitudinally, and capped on high-speed tube lines. Layer thickness variation below 8 µm EVOH can create interfacial instability and local barrier defects, so gauge control is critical. Terminal article types include ophthalmic ointment tubes, antibiotic cream tubes, high-barrier sunscreen tubes, and cosmetic foundation tubes.
Closed-loop hydronic heating systems impose oxygen ingress limits on polymer pipe to prevent corrosion of ferrous components; EVOH EV-2904 V/F is therefore coextruded as a buried core layer between peroxide-crosslinked polyethylene or silane-crosslinked polyethylene layers and compatible tie resins. The EVOH layer thickness ranges from 50–150 µm in a nominal wall thickness of 2.0–3.0 mm, corresponding to 2–5 % of the pipe wall. The function of the EVOH layer is to limit dissolved oxygen ingress into circulating heating water, with compliance tested under DIN 4726, which specifies an oxygen diffusion rate not exceeding 0.1 mg/(L·d) at 40 °C, and dimensional evaluation under ISO 15875-2. The EVOH layer is never placed as the innermost water-contact layer because continuous hot-water exposure hydrolyzes the copolymer and destroys barrier function. Production is carried out on five-layer pipe coextrusion lines with dedicated EVOH and tie-layer extruders; EVOH melt temperature is controlled within 190–210 °C, and the EVOH is pre-dried below 0.2 % moisture. After coextrusion, the pipe is crosslinked by silane moisture curing or peroxide crosslinking depending on the PE-X grade, and process conditions must avoid prolonged moisture contact with the EVOH before it is fully encapsulated. Terminal products include radiant floor heating pipe, radiator connection pipe, and oxygen-sensitive heating circuit distribution lines.
For bag-in-box liners used in oxygen-sensitive liquid packaging, EVOH EV-2904 V/F is introduced as a discrete core layer at 5–10 µm within a 60–90 µm LLDPE/tie/EVOH/tie/LLDPE blown film, representing 6–12 % of total film thickness, with oxygen transmission evaluated under ASTM D3985 at 23 °C and 50 % RH and water vapor transmission under ASTM F1249, while filled hazardous liquid packagings are qualified under ADR/RID 6.1 packaging tests; production uses a five-layer blown film line with pre-drying below 0.2 % moisture and EVOH melt temperature of 210–225 °C, and terminal articles include aseptic beverage syrup liners, edible oil bag-in-box liners, and selected specialty liquid chemical liners.
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EVOH EV-2904 V/F is a film-grade ethylene-vinyl alcohol copolymer supplied as pellets for coextruded barrier structures. The resin is specified with a nominal ethylene content of 29 mol% and a melt flow rate of 4.0 g/10 min determined by ISO 1133-1 at 210°C with a 2.16 kg load. Typical density is 1.21 g/cm³ and the crystalline melting point is approximately 191°C. These values place the material in the high-barrier segment of the EVOH family, above lower-ethylene grades in flexibility and below higher-ethylene grades in oxygen transmission rate. The intended processing routes are cast film, blown film, and sheet coextrusion where EV-2904 V/F forms the core oxygen-barrier layer between polyolefin skins and tie layers. Because published single-grade data for this specific configuration is limited, lot-specific certificates should be consulted before production scaling.
Moisture control is the first processing constraint. EVOH pellets adsorb atmospheric water at relative humidities above 60%; hydrolysis during melting releases acetic acid and generates voids. A desiccant hopper dryer operating at 80–90°C for 4–6 h reduces pellet moisture to below 0.3%. On cast film lines with extruder diameters of 65–90 mm and L/D ratios of 24:1 to 30:1, omission of this drying step has been observed to produce surface defects and layer thickness variation within 30 min of startup. Residual moisture should be verified by a moisture analyzer because regrind and plant humidity alter drying time.
| Property | Test method | Typical value |
|---|---|---|
| Ethylene content | Supplier method | 29 mol% |
| Melt flow rate | ISO 1133-1 | 4.0 g/10 min at 210°C, 2.16 kg |
| Density | ISO 1183-1 | 1.21 g/cm³ |
| Melting point | ISO 11357-3 | 191°C |
| Oxygen transmission rate | ASTM D3985 | <0.5 cm³·20 µm/(m²·day·atm) at 20°C, 0% RH |
The above values are representative supplier datasheet figures and are not lot-specific guarantees. Batch-to-batch variance in ethylene content and MFR is typically controlled within narrow limits; incoming quality control should include melt flow rate and moisture analysis.
The processing window is constrained by thermal degradation at high temperature and by melt viscosity at low temperature. Barrel temperatures should be set between 210°C and 230°C, with the feed throat at 180–200°C and the die not exceeding 240°C. Residence times above 30 min lead to gel formation and black specks in the film; degradation rate increases sharply above 240°C. Single-screw extruders with L/D ratios of 24:1 to 30:1 and moderate compression ratios avoid excessive viscous heating. High-shear mixing sections are not recommended. On blown film lines, die gaps of 0.8–1.2 mm and blow-up ratios of 2:1 to 3:1 are used. Cast film lines typically operate with a die gap of 0.3–0.5 mm and an air gap of 10–20 cm. The lower MFR of 4.0 g/10 min compared with standard 8.0 g/10 min 29 mol% grades increases die pressure and melt curtain stability; screw backpressure should be monitored against the extruder barrel limit at fixed throughput.
Rheological characterization of EV-2904 V/F should be conducted by capillary rheometry according to ISO 11443. Apparent viscosity is shear-rate dependent, and the resin exhibits shear thinning typical of EVOH. Screw designs with low-shear mixing and gradual compression reduce melt-temperature overshoot. On twin-screw compounding lines, co-rotating twin-screw extruders with L/D ratios of 40:1 or greater may be used for masterbatch dilution but are not required for converting neat EVOH. Production-scale experience shows that excessive screw speed generates local melt temperatures above 240°C even when barrel set points remain within specification, causing gel formation in the die lip area.
Purging and shutdown procedures also affect line performance. A low-density polyethylene purge at 210–230°C is used to remove EVOH from the barrel before shutdown. Direct transition from EVOH to polyamide without purging can cause interfacial degradation. Coextrusion feedblocks should be designed to avoid dead zones where residence time exceeds the 30 min limit.
Oxygen transmission rate for EV-2904 V/F is typically below 0.5 cm³·20 µm/(m²·day·atm) at 20°C and 0% relative humidity when measured according to ASTM D3985. The barrier mechanism relies on intermolecular hydrogen bonding in the vinyl alcohol segments; absorbed water disrupts this network, so oxygen permeability rises by a factor of 10–100 as relative humidity exceeds 85%. In multilayer structures, polyolefin skins and tie layers retard moisture ingress, but continuous high-humidity exposure requires a moisture barrier layer such as high-density polyethylene or polypropylene. Published data for this specific configuration is limited; oxygen transmission values from the lot certificate should be used for packaging shelf-life calculations.
Water vapor transmission rate is not the primary function of EVOH. The polar vinyl alcohol groups do not provide a high moisture barrier, and test values according to ASTM F1249 are typically one to two orders of magnitude higher than those of polyolefin layers of equivalent thickness.
Oxygen barrier design for EV-2904 V/F follows Fickian permeation. Permeability is reported as transmission rate multiplied by thickness. At 0% RH and 20°C, a 5 µm EVOH layer can provide an oxygen transmission rate near 0.1 cm³/(m²·day·atm) in a laminated structure; this value shifts with humidity and tie-layer moisture content. Packaging engineers should calculate shelf-life using the Sauerbrei equation or finite-difference permeation models with humidity-dependent permeability coefficients. Accelerated testing at 23°C and 50% RH per ASTM D3985 is recommended for product-specific validation.
Coextrusion of EV-2904 V/F requires tie layers of maleic anhydride-grafted polyolefin, typically at 10–15% of total structure thickness, to achieve interlayer adhesion. Direct contact between EVOH and polyethylene or polypropylene without a tie layer results in delamination. In five-layer cast film lines configured as A/B/C/B/A, the EVOH core layer is usually 3–10 µm of a 50–150 µm total film. For thermoformed sheet, EVOH layer thickness of 20–50 µm is selected according to the required oxygen transmission rate. The lower MFR of EV-2904 V/F improves layer stability at thin gauges but can increase interfacial instability if the die lip lands are not optimized.
Compared with a standard 29 mol% ethylene EVOH grade having an MFR of 8.0 g/10 min, EV-2904 V/F exhibits higher melt viscosity and greater melt strength. This difference reduces neck-in and draw resonance in cast film and improves bubble stability in blown film. The trade-off is higher extruder backpressure and potentially lower throughput at fixed screw speed. The grade is therefore selected when thin-layer stability and melt curtain control are more critical than maximum output. Compared with 32 mol% ethylene grades used in flexible packaging, EV-2904 V/F provides lower oxygen transmission but greater stiffness and moisture sensitivity. Compared with 38–44 mol% ethylene grades, it has a higher melting point and narrower processing window but significantly better oxygen barrier. Selection among these grades should be based on oxygen transmission requirements, flex-crack resistance, and the humidity profile of the packaged product.
Compared with polyvinylidene chloride, EV-2904 V/F has lower oxygen permeability at low relative humidity but loses barrier at high relative humidity, whereas polyvinylidene chloride retains barrier under moisture. Compared with polyamide 6, EVOH provides roughly 10–100× lower oxygen transmission at equivalent thickness but requires tie layers and moisture protection. Compared with aluminum foil, EVOH offers a transparent, microwaveable, and metal-free barrier but is not an absolute barrier; foil remains the material of choice for long shelf-life retort pouches where oxygen transmission must approach zero.
EV-2904 V/F should not be combined with amine-based additives or certain ethylene-acrylic acid ionomers without compatibility testing; amine groups promote degradation and discoloration. It is not recommended for direct contact with high-moisture liquid foods without a protective polyolefin layer. Avoid abrupt temperature swings of more than 30°C in the die because differential crystallization can cause dimensional variation. The resin is not designed for injection molding of thick sections because high shear and long flow paths degrade the barrier layer.
Food-contact compliance for EV-2904 V/F is assessed under FDA 21 CFR 177.1360 and EU Regulation 10/2011 Annex I. The base resin is an ethylene-vinyl alcohol copolymer; finished articles must meet overall migration limits of 10 mg/dm² under the specified food simulant and time/temperature conditions of EU 10/2011. For electrical and electronic applications, verification against RoHS Directive 2011/65/EU is required for lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers. Supply chains may also require confirmation of REACH registration for the monomer substances ethylene and vinyl alcohol. These assessments apply only when the resin is processed within the recommended thermal window; overheating can form degradation products not covered by the base resin compliance profile.
