| HS Code | 223420 |
| Ethylene Content Mol | 44 |
| Density G Cm³ | 1.14 |
| Melt Flow Rate 190 C 2 16 Kg G 10 Min | 4.0 |
| Melting Point C | 164 |
| Glass Transition Temperature C | 55 |
| Tensile Strength At Break Mpa | 65 |
| Elongation At Break | 220 |
| Tensile Modulus Mpa | 2600 |
| Oxygen Transmission Rate Cm³ 20μm M² Day Atm | 0.6 |
| Moisture Absorption | 8.0 |
| Crystallization Temperature C | 138 |
| Flexural Modulus Mpa | 2100 |
As an accredited EVOH EW-4401 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | EVOH EW-4401 is supplied in 25 kg sealed multi-layer paper bags, nitrogen-purged for moisture protection and safe handling. |
| Container Loading (20′ FCL) | 20′ FCL: EVOH EW-4401 packed in 25kg bags on pallets, shrink-wrapped and securely stowed for safe transport. |
| Shipping | EVOH EW-4401 is a non-hazardous, non-regulated material for transport. It ships as solid resin pellets in sealed bags, boxes, or bulk containers. Keep dry, away from moisture and direct heat. No special dangerous-goods documentation required. Standard dry cargo handling applies; store below 40°C to prevent agglomeration and preserve performance. |
| Storage | Store EVOH EW-4401 in its original, tightly sealed container in a cool, dry, well-ventilated area. Protect from direct sunlight, heat, and ignition sources. Keep away from oxidizing agents and incompatible materials. Prevent moisture absorption by keeping containers closed when not in use. Maintain temperatures below 40°C and ensure good housekeeping to avoid dust accumulation. |
| Shelf Life | Store in original sealed packaging in a cool, dry area. Shelf life is 12 months from manufacture date. |
On seven-layer cast film lines producing modified-atmosphere packaging for chilled meat and ready-meal proteins, EVOH EW-4401 is positioned in the core barrier layer between two maleic anhydride-grafted polypropylene tie layers. The structure is fed through a seven-layer feedblock and cast die with a barrier extruder of L/D 28:1, heated in a flat profile from 190 °C at the feed throat to 225 °C at the die adapter; melt temperature is kept below 230 °C to minimise gel nucleation. The EVOH layer is maintained at 3–6% of total sheet thickness, typically 5–10 µm in a 200–400 µm cast sheet, depending on the required oxygen transmission rate. Because EVOH and polypropylene are immiscible, barrier performance is achieved by layer multiplication rather than melt dispersion; dry-blending with polyolefin above 5 wt% creates laminar domains that increase oxygen transmission and reduce interlayer adhesion. Thermoforming skeleton regrind is limited to 15–20 wt% in the polyolefin skin or tie layers; direct regrind into the EVOH barrier layer above 5 wt% is not recommended without pilot validation. Compliance is anchored to FDA 21 CFR 177.1360 for the ethylene-vinyl alcohol copolymer and EU Regulation 10/2011 for overall migration. Oxygen transmission rate is measured on flat sheet and formed trays per ASTM D3985 and ASTM F1927; after plug-assisted thermoforming, corner thinning can reduce oxygen barrier by 15–30% relative to the flat sheet, so the formed tray must be the acceptance test specimen. On a 1 200 mm die width, transverse EVOH layer variation above ±0.8 µm creates measurable OTR variation; die bolt adjustment and layer distribution scans are required during start-up. Terminal formats include rigid MAP trays, cups, and deep-draw packaging for sliced meats, cheese, and ready-meal proteins.
Retort pouches impose simultaneous thermal and moisture stresses that discriminate between high-barrier EVOH grades. In a three-layer pre-laminate of PET/adhesive/EVOH or a five-layer coextruded cast film of PP/tie/EVOH/tie/PP, the EVOH EW-4401 layer is specified at 6–15 µm for total pouch thickness of 100–125 µm. The relevant regulatory framework includes FDA 21 CFR 177.1390 for high-temperature laminates and EU Regulation 10/2011 for migration. The production process is either adhesive lamination of biaxially oriented film to a coextruded barrier film or direct extrusion lamination; if adhesive lamination is used, curing is conducted at 40–50 °C for 5–7 days. The limiting phenomenon is not dry oxygen permeability but wet oxygen permeability after retort. At 20 °C, 0% RH, a 44 mol% ethylene EVOH can exhibit oxygen permeability below 0.5 cm³·mm/(m²·day·atm); at 85% RH, the value rises by more than one order of magnitude. Retorting at 121 °C for 30 min introduces 3–5 wt% moisture into the EVOH layer through adjacent polyolefin layers, and barrier recovery after cooling is incomplete. A converter that requires ≤0.5 cm³/(m²·day·atm) at 23 °C, 75% RH after retort must therefore validate the exact pouch structure; EW-4401 is used in this segment for its higher flex-crack resistance and slower moisture-induced oxygen transmission drift compared with 29–32 mol% ethylene grades, not for dry-barrier performance alone. Failure modes observed on production lines include interlayer delamination at the EVOH/tie interface when corona-treated tie film ages beyond 6 months, and gel specks when the barrier extruder is shut down without purging with low-density polyethylene. Commercial output includes stand-up pouches for tomato sauce, retortable rice pouches, and high-moisture pet food pouches.
Fuel tank shells are produced on accumulator-head or reciprocating-screw blow moulding machines with six-layer or seven-layer parison programming. The parison structure for EVOH EW-4401 is HDPE skin / regrind / tie / EVOH / tie / HDPE skin with EVOH layer volume fraction held at 2–3% of total wall volume; for a nominal tank wall thickness of 6 mm, the EVOH layer is 120–180 µm, while tie layers are 1–1.5% each. The barrier extruder operates at 190–220 °C, and the melt must avoid stagnation points in the die head because residence times above 10–15 min generate crosslinked gel particles. Regulatory compliance for evaporative emissions is demonstrated through finished-tank hydrocarbon permeation testing according to SAE J1737 and certification under CARB LEV III or ECE R34. The process conflict is weld-line integrity: at the parison pinch-off, the EVOH layer must meet and fuse without being pushed to the outside, but excessive melt pressure can displace the barrier layer and create a localized permeation path. Continuous emission testing of the welded tank is therefore more meaningful than barrier layer thickness alone. EVOH EW-4401 is suitable for gasoline and E10 service; for methanol-heavy or aggressive fuel blends, published data for this specific configuration is limited, and the converter must validate swelling, delamination, and permeation before certification. The specification therefore covers HDPE fuel tanks for passenger vehicles, motorcycle tanks, and off-road engine tanks.
| Application scenario | Primary oxygen barrier test | Process window reference | Regulatory reference |
|---|---|---|---|
| MAP thermoformed tray | ASTM F1927 at 23 °C, 50% RH and 75% RH | Barrier extruder 190–225 °C; layer ratio 3–6% | FDA 21 CFR 177.1360; EU 10/2011 |
| Retort pouch | ASTM F1927 at 23 °C, 75% RH after 121 °C retort | EVOH layer 6–15 µm; pouch total 100–125 µm | FDA 21 CFR 177.1390; EU 10/2011 |
| HDPE fuel tank | SAE J1737 hydrocarbon permeation | EVOH layer 2–3 vol%; parison wall 6 mm | CARB LEV III; ECE R34 |
| Pharmaceutical blister base film | ASTM F1927 on formed cavities | EVOH layer 15–30 µm; forming 150–170 °C | USP <661.1>; USP <661.2>; ICH Q1A(R2) |
| Oxygen barrier pipe | ISO 17455; DIN 4726 | EVOH layer 0.10–0.25 mm; melt 195–220 °C | DIN 4726; ISO 17455 |
| Cosmetic tube | ASTM D3985 at 23 °C, 50% RH | EVOH layer 10–20 µm; wall 250–400 µm | EU 1223/2009; EU 10/2011 |
In dry-powder inhaler and effervescent tablet blister lines, the base film is a three- or five-layer cast structure in which EVOH EW-4401 is embedded between polyethylene or polypropylene skin layers. The EVOH layer is maintained at 15–30 µm in a total base film of 250–400 µm, corresponding to 5–10% of total thickness. The film is produced by cast coextrusion with a barrier extruder temperature of 190–220 °C, and then converted on contact-heated plug-assisted thermoforming machines at 150–170 °C. Compliance for pharmaceutical packaging requires the finished blister film to meet USP <661.1> plastic materials of construction, USP <661.2> plastic packaging systems for pharmaceutical use, and the relevant polyethylene or polypropylene monograph; stability studies follow ICH Q1A(R2) protocols. The critical process constraint is corner thinning during forming: a 30 µm EVOH layer can thin to 10 µm or less in deep-draw cavities, so oxygen barrier must be tested on the formed blister rather than on flat film. Published data for EW-4401-specific forming window is limited; a line qualification should map plug speed, film surface temperature, and draw ratio against post-formed oxygen transmission measured by ASTM F1927. Static film handling and web blocking are prevented by maintaining the cast line in a low-humidity area; EVOH exposure to ambient air above 60% RH for more than 6 h requires pre-drying to <0.15% moisture. The film is subsequently qualified as lidding-free base web for blister cards, push-through blister base films, and moisture-protection trays for diagnostic reagents.
Five-layer PE-RT or PEX pipes with an internal EVOH oxygen barrier layer are extruded on coextrusion lines with a spiral mandrel die; the EVOH EW-4401 layer is placed between two maleic anhydride-grafted polyethylene tie layers to prevent delamination under thermal cycling. The EVOH layer thickness is specified at 0.10–0.25 mm, which is 3–8% of a pipe wall of 4–10 mm in underfloor heating service. The barrier extruder is typically a 35–45 mm single-screw with L/D 24:1; melt temperature is controlled at 195–220 °C to avoid carbonization at high backpressure. Compliance with oxygen diffusion limits is tested according to DIN 4726 and ISO 17455; the final pipe must demonstrate that the oxygen barrier layer remains continuous after bending and thermal ageing. In production, the main defect is waviness or thinning of the EVOH layer caused by die-runner imbalance; cross-sectional microscopy is used to confirm layer concentricity. EVOH EW-4401 must be pre-dried to <0.15% moisture when exposed to ambient air above 60% RH for more than 6 h; otherwise moisture-induced microvoids in the barrier layer reduce oxygen tightness. The extruded pipe is documented for use as PE-RT and PEX pipe in radiant floor heating, radiator connections, and district heating distribution lines.
Cosmetic tube sleeves are produced by coextruding a multilayer web that is welded longitudinally and cut into tube bodies before shoulder injection moulding. In this structure, EVOH EW-4401 is buried between LDPE skin layers and bonded with maleic anhydride-grafted ethylene copolymer ties; the barrier layer is 10–20 µm in a total tube wall thickness of 250–400 µm, equivalent to 5–8% of the wall. The coextrusion line runs at 190–220 °C with a multi-manifold die; edge trim from tube body punching is recycled into the outer skin layer at 10–20 wt%, but not into the EVOH barrier layer. Regulatory compliance for the finished tube is assessed under EU Regulation 1223/2009 for cosmetics, EU Regulation 10/2011 for food-contact grades when cross-used, and FDA 21 CFR 175.105 for functional barriers if the tube contains food-like cosmetic excipients. Oxygen permeation of the finished tube is measured by ASTM D3985 on flat samples cut from the sleeve; the OTR target is usually 0.3–1.0 cm³/(m²·day·atm) at 23 °C, 50% RH. The main production failure is barrier layer fracture at the tube shoulder after compression moulding; shoulder temperature above 220 °C can cause localized EVOH decomposition, so melt temperature is limited. The finished tube product is qualified as barrier tubes for sunscreen, fluoride toothpaste, hair colorant, and pharmaceutical ointment tubes.
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EVOH EW-4401 is a high-ethylene ethylene-vinyl alcohol copolymer barrier resin in which the numerical suffix identifies a nominal ethylene content of 44 mol%. The resin sits between 32 mol% and 48 mol% ethylene grades in the EVOH property envelope: dry oxygen barrier is lower than that of 32 mol% grades, while flex-crack resistance, drawability, and relative barrier retention at high relative humidity are improved. Melt flow rate is typically reported in the range 1.5–4.0 g/10 min at 190 °C under 2.16 kg load according to ISO 1133-1:2022. Density is approximately 1.12–1.14 g/cm³ after conditioning at 23 °C and 50 % RH. Tensile yield strength is generally reported between 55 MPa and 70 MPa, with elongation at break from 200 % to 300 % under ISO 527-2. The resin is supplied as pellets with moisture content below 0.3 % in sealed packaging; if hoppers are opened at relative humidity above 60 % RH, drying at 80–90 °C for 4–6 h is required before processing to prevent hydrolysis and bubble formation in the melt.
Process applications for EVOH EW-4401 include multilayer coextrusion, extrusion lamination, sheet thermoforming, and coextrusion blow molding. The grade is not intended as a tie layer or as a monolayer film. In production-scale coextrusion, EW-4401 is run as a core layer between polyolefin skins. Barrel temperature profiles from 180 °C in the feed section to 225 °C at the metering section are typical for single-screw extruders with L/D ratios between 24:1 and 30:1. Measured melt temperature at the die entry is usually maintained between 210 °C and 225 °C. At these conditions, the melt viscosity of high-ethylene EVOH is lower than that of a 32 mol% grade, which reduces die pressure and improves thin-layer distribution.
Melt processing of EVOH EW-4401 requires control of moisture, temperature, and residence time. Moisture must be reduced to below 0.3 % by weight before melting. In plants where opened hoppers are exposed to relative humidity above 60 % RH, pellet dryers operating with desiccated air at 80–90 °C for 4–6 h are standard. Drying temperature should not exceed 105 °C because prolonged thermal exposure promotes yellowing and gel formation. The feed throat should be purged with dry nitrogen when transferring dried resin, as EVOH rapidly reabsorbs atmospheric moisture.
Screw designs with gradual compression and no high-shear mixing elements are preferred; excessive shear work raises melt temperature above 240 °C and accelerates crosslinking. Residence time in the extrusion system should not exceed 30 min. Stagnant regions in the adapter, screen changer, or coextrusion feedback create dark, crosslinked specks. Purging with low-density polyethylene after production is recommended. Acid-functional purge compounds and amine-containing processing aids should be avoided because the hydroxyl groups of EVOH react by esterification or base-catalyzed chain scission, forming gel deposits at stainless steel surfaces and altering melt strength.
Adhesion to polyolefin skins in coextrusion is achieved with maleic anhydride-grafted polyolefin tie layers, typically at 5–15 % of total film thickness. The anhydride groups react with surface hydroxyls of EW-4401 during melt contact, forming a covalent ester bond at the interface. When the tie layer is too thin, intermittent delamination appears during flex testing; when it is too thick, the barrier core is thermally shielded but the recyclate stream becomes more complex. Die buildup is reduced with EW-4401 compared with lower-ethylene grades because the higher ethylene content lowers the concentration of oxidatively labile secondary alcohol functionalities at the die lip. However, interface temperatures below 190 °C reduce tie-layer reaction rates and may produce peel strength below 3 N/15 mm, while temperatures above 235 °C produce gel-like interfacial roughness.
Oxygen transmission rate for EVOH EW-4401 is a function of layer thickness, relative humidity, and temperature. At 23 °C and 0 % RH, a 20 µm core layer typically exhibits oxygen transmission in the range 2.0–4.0 cm³/(m²·day·atm) when measured according to ISO 15105-2 or ASTM D3985. At 65 % RH, the value rises to approximately 6–12 cm³/(m²·day·atm) for the same thickness because water molecules plasticize the amorphous phase and disrupt intermolecular hydrogen bonding between vinyl alcohol repeat units. The relative increase is smaller than for 32 mol% ethylene grades, which can show a 5× to 10× loss in oxygen barrier between 0 % RH and 65 % RH. The higher ethylene content of EW-4401 reduces the number of water-sensitive hydroxyl group clusters per unit volume. This is a relevant selection criterion for high-moisture food packaging where the barrier layer is positioned between polyolefin layers that provide limited moisture protection.
The water vapour transmission rate of the grade is not a primary specification because EVOH is generally protected by polyolefin skins; however, high ethylene content increases equilibrium water uptake by 30–50 % relative to 32 mol% grades at 25 °C immersion according to ISO 62. The grade is therefore not recommended as a direct food-contact layer in retort or hot-fill applications without a protective moisture barrier.
In deep-draw thermoformed trays and cups, EVOH EW-4401 is selected when the increase in oxygen transmission can be accepted in exchange for a reduction in corner thinning and stress cracking. The higher ethylene content lowers the modulus of the barrier layer, allowing it to follow the deformation of polypropylene or polystyrene skins without fracture. In plug-assisted thermoforming with sheet temperatures between 140 °C and 165 °C, sheet containing EW-4401 can be drawn to area ratios of 3.5:1 to 4.5:1 without visible barrier-layer splits, whereas a 32 mol% EVOH layer frequently develops microcracks at corner radii below 2 mm. The resulting oxygen transmission rate at the corner is therefore reduced by 40–60 % relative to the lower-ethylene grade after forming, despite the lower intrinsic dry barrier of the resin.
This substitution is not appropriate when the oxygen ingress specification for the formed part is below 0.5 cm³/(m²·day·atm) at 23 °C and 50 % RH. In those applications, a 32 mol% grade with a coextruded tie layer and thicker skins should remain, or a secondary oxygen scavenger must be added. Conversely, EW-4401 may replace a 48 mol% ethylene grade when the application requires better oxygen barrier but cannot tolerate the lower flexibility of the 48 mol% grade. Selection depends on the formed-part oxygen transmission specification and on the distribution of barrier-layer thickness after thermoforming, as measured by cross-sectional microscopy.
| Parameter | 32 mol% ethylene grade | 44 mol% ethylene grade (EW-4401 class) | 48 mol% ethylene grade | Standard method |
|---|---|---|---|---|
| Oxygen transmission rate, 20 µm, 23 °C, 0 % RH | 0.4–1.0 cm³/(m²·day·atm) | 2.0–4.0 cm³/(m²·day·atm) | 4.0–7.0 cm³/(m²·day·atm) | ASTM D3985 / ISO 15105-2 |
| Oxygen transmission rate, 20 µm, 23 °C, 65 % RH | 3.0–8.0 cm³/(m²·day·atm) | 6.0–12.0 cm³/(m²·day·atm) | 12.0–20.0 cm³/(m²·day·atm) | ASTM D3985 |
| Density, 23 °C | 1.18–1.21 g/cm³ | 1.12–1.14 g/cm³ | 1.09–1.11 g/cm³ | ISO 1183-1 |
| Melt flow rate, 190 °C, 2.16 kg | 1.3–3.2 g/10 min | 1.5–4.0 g/10 min | 2.0–5.0 g/10 min | ISO 1133-1:2022 |
| Melting temperature, DSC | 180–190 °C | 158–168 °C | 150–160 °C | ISO 11357-3 |
| Flexural modulus, 23 °C, 50 % RH | 3200–3800 MPa | 2200–2800 MPa | 1800–2300 MPa | ISO 178 |
Blow-molded containers produced with EW-4401 as an intermediate layer in polyolefin substrates require multiflow die heads capable of maintaining layer continuity at the pinch-off. The higher melt strength of the 44 mol% grade relative to 48 mol% EVOH reduces parison sag during continuous extrusion blow molding, but it is not as strong as 32 mol% grades. When the barrier layer represents 2–4 % of total wall thickness, measured oxygen ingress through a 0.5 mm sidewall is commonly less than 2.0 cm³/(m²·day·atm) at 23 °C and 50 % RH. The same structure at 85 % RH shows oxygen ingress above 10 cm³/(m²·day·atm) because moisture penetrating from the outer polyolefin plasticizes the EVOH. The grade is therefore used with a moisture barrier such as polyethylene or polypropylene in the outer layer; in high-humidity environments, the barrier layer can be moved closer to the inner surface to limit water contact. Published data for this specific configuration is limited, and pilot trials are required.
EVOH can be used for food contact applications. In the EU, vinyl alcohol polymers are covered by Commission Regulation EU 10/2011 as a polymer class, with migration limits for monomers and additives. In the US, EVOH may be used in food packaging under FDA 21 CFR 177.1360 when specified conditions of use are met. EW-4401 should be verified against the manufacturer’s food-contact statement for specific polymerisation aids, residual solvents, and compliance with REACH Article 33 candidate list obligations.
For retort applications above 121 °C, the hydrolytic stability of EVOH decreases with time at temperature. EW-4401 retains a higher proportion of its original oxygen barrier at elevated humidity than lower-ethylene grades, but prolonged retorting of 60–90 min at 121 °C causes progressive hydrolysis and blistering unless the layer is protected by polypropylene skins and robust tie layers. The use of recycled trim containing EW-4401 in direct food contact is subject to national recycled plastics legislation; the multilayer nature of trim generally excludes it from closed-loop post-consumer recycling streams under current mechanical recycling infrastructure.
EVOH EW-4401 is incompatible with high-acid aqueous foods if used as a direct contact layer without protective skins because water and acetic acid absorption degrade oxygen barrier and promote delamination. It is also incompatible with strong oxidizing agents and with primary amines that can react with residual hydroxyl groups. In extrusion lamination, the resin should not be processed on equipment contaminated with PVC or vinylidene chloride copolymers; dehydrochlorination products from halogenated materials accelerate darkening and release corrosive gases. The lower melting point of the 44 mol% grade compared with 32 mol% EVOH also means that downstream hot-fill temperatures above 95 °C can soften the barrier layer and increase oxygen transmission by 2× to 3× relative to the 65 % RH value; this is a design boundary rather than a defect.
Compared with PVdC copolymers, EVOH EW-4401 offers lower oxygen transmission at dry conditions but poorer moisture-driven barrier retention; compared with polyamide MXD6, it provides a sharper oxygen barrier at low thickness but requires more moisture protection. Compared with aluminium foil, EVOH EW-4401 is a transparent barrier and can be used in microwaveable packaging, but it has an oxygen transmission rate that is orders of magnitude higher than foil and is not suitable for ultra-high-barrier pharmaceutical blister packs requiring oxygen ingress below 0.01 cm³/(m²·day·atm). In flexible packaging, the replacement of foil with EVOH EW-4401 allows weight reduction of the laminate by 30–50 % and removes the cracking failure mode associated with metal foil dead fold. However, the resulting structure is not a total barrier and must be evaluated against the product shelf-life requirement using ASTM F1927 or internal oxygen ingress models.
