| HS Code | 398077 |
| Ethylene Content | 32 mol% |
| Density | 1.19 g/cm³ |
| Melting Point | 183 °C |
| Glass Transition Temperature | 62 °C |
| Melt Flow Rate | 1.6 g/10 min (210°C, 2.16 kg) |
| Oxygen Transmission Rate | 0.5 cc·mm/m²·day·atm |
| Tensile Strength | 70 MPa |
| Elongation At Break | 230% |
| Flexural Modulus | 3100 MPa |
| Water Absorption 24h | 6.5% |
| Haze | 2% |
| Light Transmittance | 90% |
| Thermoforming Temperature Range | 150-170 °C |
| Sheet Thickness Range | 0.1-1.5 mm |
As an accredited Thermoforming Grade EVOH for Sheets factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged in moisture-resistant 25 kg bags, sealed for safe transport and storage of Thermoforming Grade EVOH resin sheets. |
| Container Loading (20′ FCL) | Thermoforming Grade EVOH for Sheets loaded as 20' FCL in palletized, sealed moisture-proof bags, ensuring safe transport and stability. |
| Shipping | Ship as resin pellets in sealed, moisture-barrier bags or FIBCs with desiccant, ensuring dry, clean transport. Protect from humidity and direct sunlight to prevent moisture absorption and degradation. Use covered containers, avoid extreme temperatures, and secure loads properly. Include handling instructions for controlled, low-humidity storage. |
| Storage | Store in a cool, dry, well-ventilated area, away from direct sunlight, heat, and ignition sources. Keep the original sealed container or packaging intact to prevent moisture absorption, as EVOH is hygroscopic. Avoid high humidity and drastic temperature changes. Maintain temperatures between 15–25°C. Use within the manufacturer’s stated shelf life to preserve processing performance. |
| Shelf Life | Store in a cool, dry place away from moisture and sunlight; typical shelf life is 12 months from date of delivery. |
A three-layer PP/EVOH/PP sheet for retortable food trays is coextruded on a cast line equipped with barrier screws of 30:1 L/D ratio and a multi-manifold die, with the EVOH layer held at 5–8 vol% of total sheet thickness and maleic anhydride-grafted PP tie layers at 2–3 vol% per side; for a total sheet gauge of 700–1,200 µm, the dry EVOH layer is selected at 30–45 µm. Food-contact compliance of the finished structure is established under 21 CFR § 177.1360, EC 1935/2004, and Commission Regulation (EU) No 10/2011 as amended by Regulation (EU) 2016/1416, with overall migration tested per EN 1186-1 and retort simulant migration conducted per EN 1186-14. On production-scale cast lines, the practical processing boundary is generated by the viscosity ratio between the EVOH core and PP skins; EVOH with a melt flow index of 3–6 g/10 min at 190 °C/2.16 kg per ISO 1133-1:2022 is matched against PP skins of 1.5–3 g/10 min at 230 °C/2.16 kg to prevent disturbed layer distribution and edge-trim delamination. The EVOH melt temperature is limited to 210–230 °C; exposure above 240 °C for more than 15–20 min produces gel specks and black specks in the sheet. Feedstock moisture must be below 0.3 %, and closed-loop regrind is usually capped at 10–15 % total layer weight because excess edge trim shifts oxygen transmission of the barrier layer and raises haze. Thermoforming is conducted on servo-driven plug-assist machines at sheet surface temperatures of 150–165 °C for PP skins and plug temperatures of 90–110 °C; draw ratios are typically limited to 1.4:1. Retort at 121 °C for 45 min causes moisture-mediated oxygen transmission increase in EVOH; when measured by ASTM D3985 at 23 °C/50 % RH, a 35 µm dry EVOH layer typically shows 0.02–0.06 cm³/(m²·day·atm) before retort and 0.3–0.7 cm³/(m²·day·atm) after retort, though published data for this specific configuration is limited and line-specific validation is required. Terminal product types include retortable ready-meal trays for meat and sauce, shelf-stable pet food trays, and lidded vegetable meal trays.
| Relative humidity | Oxygen transmission of a 30 µm EVOH layer in PP/EVOH/PP sheet |
|---|---|
| 0 % RH | 0.02–0.06 cm³/(m²·day·atm) |
| 50 % RH | 0.04–0.12 cm³/(m²·day·atm) |
| 75 % RH | 0.08–0.25 cm³/(m²·day·atm) |
| 85 % RH | 0.15–0.50 cm³/(m²·day·atm) |
Low-haze transparent cup stock is coextruded as a three-layer PP/EVOH/PP sheet on a cast line with polished cooling rolls, where the EVOH layer is added at 3–5 vol% and the total sheet thickness is 800–1,400 µm; the dry EVOH gauge is selected at 20–35 µm for high-acid hot-fill products with pH below 4.6 because the acid product does not require post-fill retort and the oxygen barrier must survive hot filling at 82–88 °C. Compliance for these structures is established under 21 CFR § 177.1360, EC 1935/2004, and Commission Regulation (EU) No 10/2011 as amended by Regulation (EU) 2016/1416; the transparent PP skins are specified with a haze value below 5 % per ASTM D1003 and low-gloss variation across the sheet width. The downstream production sequence usually combines inline coextrusion and thermoforming on cup lines with 2–5 cavities per index; sheet surface temperature is controlled at 152–165 °C, and plug assist is adjusted to keep the EVOH core thickness in the cup sidewall above 8–12 µm, because sidewall thinning below this range creates an oxygen transmission cliff-edge measured by ASTM D3985. In production, the barrier layer is not merely a formulation percentage; the EVOH melt is held at 210–230 °C, and the surrounding PP skins are run at 230–250 °C to maintain interface adhesion without thermally degrading the core. The critical process conflict is moisture: EVOH oxygen transmission at 85 % RH can be 4–8 times higher than the dry value, so high-acid cups stored in tropical relative humidity conditions are designed with a thicker core or a desiccant masterbatch in the cap liner when shelf life exceeds 9–12 months. Terminal product types include hot-filled fruit cocktail cups, applesauce cups, dairy creamer cups, and clear portion containers for acidic condiments.
Intermittent-motion pharmaceutical blister lines process a coextruded PVC/EVOH/PE or PP/EVOH/PP web in which the EVOH layer is added at 15–25 µm, corresponding to 4–7 wt% of a 300–500 µm thermoforming web, and the tie layer thickness is 8–12 µm per side. Compliance for pharmaceutical packaging is evaluated under Ph. Eur. 3.2.2, USP <661>, ISO 11607-1:2019 for terminally sterilized medical device barrier systems, and the food-contact provisions of 21 CFR § 177.1360 and Commission Regulation (EU) No 10/2011 for extractables; seal strength is measured on peel coupons cut from formed cavities according to ASTM F88/F88M at a crosshead speed of 300 mm/min, with acceptance values between 1.5 N/15 mm and 2.5 N/15 mm depending on the lidstock lacquer. The web is produced on a cast coextrusion line with an EVOH melt temperature of 220–230 °C and core residence time below 20 min; polyvinyl chloride skins are run under a separate thermal profile because PVC degradation begins above 200 °C, so the multi-manifold die is designed to keep the EVOH core hotter than the skins during convergence. Thermoforming on medication blister machines uses water-cooled plug assist to avoid scorching the EVOH layer; cavitation depth is 10–25 mm, and sidewall thinning reduces the EVOH barrier disproportionately at the base corners, so post-formation oxygen transmission is verified on the deepest cavity by ASTM D3985 at 23 °C/50 % RH rather than on the unformed web. Terminal product types include unit-dose pharmaceutical blister packs, medical device trays for syringes and catheters, and diagnostic reagent kit trays.
| Requirement | Standard designation | Test condition |
|---|---|---|
| Plastic containers for medicinal products | Ph. Eur. 3.2.2 | Extraction and visual conformity |
| Sterile barrier system | ISO 11607-1:2019 | Design and integrity validation |
| Seal strength | ASTM F88/F88M | 300 mm/min |
| Oxygen transmission | ASTM D3985 | 23 °C/50 % RH |
| Food-contact migration | 21 CFR § 177.1360, EU 10/2011 | Simulant-dependent migration testing |
Single-serve beverage capsule sheet is coextruded as a three-layer PP/EVOH/PP structure on a cast line with a feedblock and a flex-lip die, with the EVOH layer controlled at 4–6 vol% and a dry EVOH gauge of 20–35 µm within a 550–900 µm sheet; the PP skins are selected from high-stiffness random copolymer grades to permit capsule wall thickness of 250–350 µm after thermoforming without collapsing during brewing pressure. Compliance for the complete capsule is established under 21 CFR § 177.1360, EC 1935/2004, and Commission Regulation (EU) No 10/2011 as amended by Regulation (EU) 2016/1416; oxygen transmission of the formed capsule body is tested according to ASTM D3985 at 23 °C/50 % RH, with typical target values below 0.08 cm³/(m²·day·atm) for coffee capsules to protect lipid oxidation over 12–18 months. Downstream, the sheet is fed into rotary or inline thermoforming machines running 35–45 cycles/min; plug-assisted forming at 160–175 °C produces a draw ratio of 2:1–2.5:1, which is the upper limit for maintaining continuous EVOH core coverage in the bottom corner of the capsule. The production bottleneck is core thinning at the bottom corner: if nominal EVOH thickness falls below 10 µm, the capsule shows a measurable increase in oxygen transmission and can fail aroma retention, so the sheet gauge and EVOH thickness are set to compensate for draw-induced thinning. Pre-drying of EVOH to below 0.3 % and control of edge trim regrind below 10 % are mandatory to prevent microvoids at the skin-core interfaces. Terminal product types include single-serve coffee capsules, tea pods, and dairy creamer capsules.
Cosmetic single-dose barrier packs are formed from a coextruded PP/EVOH/PE sheet with EVOH at 3–5 wt%; the dry EVOH layer is 15–25 µm in a 400–700 µm sheet, and the PE skin is selected for peel compatibility with foil lidstock. The regulatory assessment for the pack is based on EC 1935/2004 where the sample may enter the mouth, Regulation (EC) No 1223/2009 for compatibility between the cosmetic formulation and the plastic pack, and REACH Regulation (EC) No 1907/2006 for substance registration and candidate-list SVHC confirmation below 0.1 wt% per Article 33; where an oral-care sample is marketed, 21 CFR § 177.1360 may apply as a secondary food-contact reference. The sheet is produced on a cast line with mirror-finish rolls and a barrier screw of 28:1 L/D ratio; EVOH is dried to less than 0.3 % moisture and processed at 210–225 °C to avoid gel formation. Thermoforming on high-speed visual blister machines uses shallow cavities with plug assistance at 160–175 °C, and foil lid sealing is conducted at 150–190 °C with seal integrity checked by dye-penetration test per ASTM F3039. Terminal product types include fragrance sample blisters, single-dose retinol serum packs, and sunscreen sample pods.
Deep-draw modified atmosphere packaging tray sheet is coextruded as a PE/EVOH/PE or PP/EVOH/PE structure with EVOH at 4–7 vol% and a dry EVOH layer of 25–45 µm in a 1,000–2,000 µm sheet; this thickness is selected because draw ratios above 1.5:1 can thin the EVOH layer in tray corners below 10–12 µm, creating a barrier cliff-edge that is not visible in routine average barrier measurements. The sheet is produced on a cast coextrusion line with a multi-manifold die and downstream deep-draw thermoforming machines with plug-assisted forming; PE skins are formed at sheet surface temperatures of 95–125 °C, PP skins at 150–165 °C, and the EVOH melt is held at 210–230 °C during extrusion. Oxygen transmission is measured by ASTM D3985 at 23 °C/50 % RH and 85 % RH; typical corner values after deep draw may be 0.4–0.8 cm³/(m²·day·atm) at 50 % RH for a nominal 30 µm EVOH layer, while the flat unformed sheet value is 0.04–0.08 cm³/(m²·day·atm). Compliance is established under 21 CFR § 177.1360, EC 1935/2004, and Commission Regulation (EU) No 10/2011 as amended by Regulation (EU) 2016/1416, with overall migration tested per EN 1186-1 and fatty-food simulant testing per EN 1186-14 where the tray contacts meat lipids. Terminal product types include case-ready red meat trays flushed with 70–80 % O₂/20–30 % CO₂, seafood trays flushed with 70 % CO₂/30 % N₂, and bakery clamshells with moisture-resistant barrier.
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Thermoforming-grade ethylene vinyl alcohol (EVOH) for sheet is a melt-extrudable copolymer supplied for coextrusion as the oxygen-barrier layer in rigid multilayer structures. The copolymer contains 38 mol% to 44 mol% ethylene, with density 1.17–1.19 g/cm³ per ISO 1183-1:2019 and melt flow rate 1.5–4.0 g/10 min at 190 °C/2.16 kg per ISO 1133-1:2022. The sheet-conversion profile is distinguished from film-grade EVOH by a narrower MFR band and higher melt strength, both required to resist web sag during contact-heating ovens and plug-assisted forming. Oxygen transmission rate at 23 °C and 0 % RH, measured on 20 μm cast film per ASTM D3985-17, typically falls between 0.4 cm³·20 μm/(m²·day·atm) and 1.5 cm³·20 μm/(m²·day·atm) depending on ethylene content. These values are dry-condition reference points; barrier performance at food-packaging relative humidity is addressed below.
Across standard film-grade and thermoforming-grade EVOH products, the differentiation rests on melt flow rate, ethylene content, and extensional viscosity. Standard monolayer or barrier-film EVOH grades are produced with MFR values commonly above 5 g/10 min and ethylene contents of 29–32 mol%; these materials orient well in biaxial film lines but lack the sag resistance needed for sheet heating. Thermoforming grades are controlled to MFR 1.5–4.0 g/10 min at 190 °C/2.16 kg and ethylene contents of 38–44 mol%. The higher ethylene incorporation lowers peak melting point by differential scanning calorimetry per ISO 11357-3:2018 to 163–183 °C, which widens the forming window without approaching the 240 °C thermal-degradation threshold. The difference from standard extrusion barrier grades is observed on production lines as reduced web sag before tool entry and more uniform barrier-layer thickness distribution after plug draw.
Compared with barrier solutions such as PVDC, the EVOH layer is halogen-free and can be coextruded without solvent-borne coating dryers. However, oxygen barrier in EVOH is humidity-dependent, whereas PVDC retains a less variable barrier above 80 % RH; this boundary dictates that EVOH-based sheet structures use hydrophobic polyolefin cap layers. Compared with aqueous EVOH dispersion coatings, extruded EVOH sheet layers are continuous, thickness-controlled, and not reliant on post-extrusion drying; edge-trim recycle is more complex, as described below.
In production-scale coextrusion, the EVOH layer is most frequently interleaved between polypropylene cap layers and adhesive tie layers to form PP/tie/EVOH/tie/PP sheet. The EVOH proportion is maintained at 3–8 wt% of total sheet mass, corresponding to a barrier-layer thickness of 3–10 μm after stretching. Feedblock temperature is held at 220–235 °C, and the sheet die is designed with a positive pressure differential across the EVOH channel to prevent layer inversion; chrome-plated or nitrided tooling is used because EVOH can liberate volatile oxidation by-products at processing temperatures above 240 °C. Extruder screw configurations for EVOH are single-screw designs with 24:1 L/D and barrier flights; compression ratios below 3.0:1 reduce shear work. The viscosity mismatch with polypropylene is managed by matching EVOH melt temperature to PP melt temperature within ±5 °C at the die; a wider mismatch produces visible interface distortion at layer boundaries. Dryer settings are 80–90 °C for 4–8 h with a residual moisture specification below 0.3 wt%; pre-drying is required when ambient relative humidity exceeds 60 %.
For plug-assisted sheet lines, sheet sag before tool entry is controlled by zero-shear viscosity and extensional hardening. Thermoforming EVOH grades are formulated with long-chain branching or controlled molecular weight distribution to raise melt strength relative to film grades. At the forming temperature of the polypropylene cap layer, 150–170 °C, the EVOH layer remains below its crystalline melt and contributes to localized sheet stiffness; therefore the oven set point is trimmed to keep the web surface temperature within ±5 °C across the transverse direction. Plug-assisted forming at draw ratios from 1:1 to 4:1 produces barrier-layer thinning; a 10 μm preform EVOH layer may thin to 6–8 μm in tray corners. Thinning below 3 μm is associated with optical haziness and loss of continuity in the barrier layer. Tensile properties per ISO 527-2:2012 for thermoforming-grade EVOH indicate yield strength of 60–85 MPa and elongation at break above 200 % at 23 °C; these values support the deep-draw requirement of ready-meal trays.
In rigid tray applications, polypropylene-based sheet is selected for microwavable and hot-fill trays; polystyrene-based sheet appears in barrier drink cups and modified-atmosphere trays. The tie layer is chosen from maleated polypropylene for PP caps or styrenic block copolymer adhesive for PS caps; tie-layer thickness is held at 3–5 μm before stretching. Delamination at the PP/tie/EVOH interface is monitored by peel testing per ASTM F904-16 and should exceed 300 g/25 mm for rigid-tray integrity after vacuum skin sealing. For PS/EVOH/PE configurations, the EVOH layer is buried against a polyethylene sealant layer to limit moisture uptake during chilled storage. Sheet is extruded at total thickness 0.35–1.2 mm; the EVOH layer is centered asymmetrically when downstream filling requires a thicker outside cap. Hot-fill exposure at 85 °C for 30 min does not exceed the continuous-use temperature of EVOH, but steam retort at 121 °C is outside the recommended boundary because moisture-driven barrier loss recovers slowly after cooling.
During edge-trim recovery, trim from multilayer sheet containing EVOH is reintroduced into the polypropylene cap or regrind layer after grinding. Addition levels above 10 wt% create discrete EVOH domains that scatter light and reduce cap-layer impact strength; the effect is quantified by notched Izod impact testing per ASTM D256-23 on formed trays. Because EVOH is incompatible with PP and PS matrices, no mixing section or static mixer is specified for the regrind stream; dispersive mixing is confined to the cap-layer screw. Extruder output stability is affected by EVOH moisture: feed zone slip and melt-pressure oscillation are observed at residual moisture above 0.3 wt%. Production lines use desiccant-wheel dryers with dew points below -40 °C and insulated vacuum loaders to prevent re-humidification of dried pellets.
Under dry conditions, EVOH oxygen transmission rates are measured as a reference because water vapour disrupts interchain hydrogen bonding. The humidity effect is not linear; barrier loss accelerates above 65 % RH. Three representative ethylene-content classes are shown below for 20 μm film; values are reported per ASTM D3985-17 at 23 °C and the stated relative humidity for the oxygen side, with nitrogen-carrier gas per ASTM F1927-20.
| Ethylene content | MFR at 190 °C/2.16 kg | Peak melting point per ISO 11357-3:2018 | OTR at 0 % RH | OTR at 65 % RH | OTR at 90 % RH |
|---|---|---|---|---|---|
| 32 mol% film reference | 4.0–8.0 g/10 min | 183–191 °C | 0.2–0.5 | 2–6 | 10–20 |
| 38 mol% thermoforming | 1.7–3.2 g/10 min | 172–183 °C | 0.4–0.8 | 4–8 | 20–40 |
| 44 mol% thermoforming | 1.5–2.5 g/10 min | 163–172 °C | 0.8–1.5 | 6–12 | 30–60 |
For chilled food trays, the consequence for sheet packaging is that the hydrophobic cap layers must delay moisture ingress to the EVOH core. In a PP/EVOH/PP tray stored at 4 °C and 90 % RH external environment, the core relative humidity may remain below 60 % for shelf-life windows of 14–30 days, depending on cap-layer thickness of 250–600 μm. For long shelf-life retort or high-moisture pouches, EVOH is used only with an additional barrier layer or is replaced by aluminum-foil laminates; published data for this specific configuration is limited.
When food-contact status is required, thermoforming-grade EVOH must comply with regional positive lists. In the United States, EVOH copolymers with ethylene content appropriate for barrier layers are covered under FDA 21 CFR 177.1360 when the end use is food packaging. In the European Union, the material falls within Regulation EU 10/2011 as amended, with overall migration limits specified at 10 mg/dm² and specific migration limits for ethylene glycol and vinyl alcohol as specified in the regulation. Heavy metals and phthalate requirements are evaluated per Directive 94/62/EC for packaging and REACH Article 33 for substances of very high concern. The table below summarizes the verification methods used for sheet converters.
| Requirement | Standard or regulation | Test method or specification |
|---|---|---|
| US food-contact resin status | FDA 21 CFR 177.1360 | Ethylene vinyl alcohol copolymer barrier layer |
| EU overall migration | EU 10/2011 | EN 1186-1:2002; limit 10 mg/dm² |
| Melt flow rate | ISO 1133-1:2022 | 190 °C/2.16 kg |
| Density | ISO 1183-1:2019 | 1.17–1.19 g/cm³ |
| Oxygen transmission | ASTM D3985-17 / ASTM F1927-20 | 23 °C; 0/65/90 % RH |
| Peel adhesion | ASTM F904-16 | 300 g/25 mm minimum |
Sheet converters should also verify dryer dew point, melt-pressure stability, and die-lip deposits at start-up. Die-lip buildup from EVOH oxidation by-products is removed by LDPE purges at the end of each run; purge duration of 10–20 min at 230 °C is typical on 1,000 mm sheet lines. Failure to purge after EVOH coextrusion can leave carbonized residues that fracture along the die lip and create machine-direction streaks in the next PP sheet run.
