| HS Code | 503199 |
| Product Name | EVAL G156B |
| Resin Type | Ethylene Vinyl Alcohol (EVOH) Copolymer |
| Ethylene Content | 48 mol% |
| Density | 1.12 g/cm³ |
| Melt Flow Rate | 3.6 g/10 min at 190°C, 2.16 kg |
| Melting Point | 165 °C |
| Glass Transition Temperature | 56 °C |
| Crystallization Temperature | 135 °C |
| Tensile Strength At Break | 55 MPa |
| Elongation At Break | 200% |
| Flexural Modulus | 2200 MPa |
| Oxygen Transmission Rate | 2.4 cm³/(m²·day) for 20 µm film at 20 °C, 65% RH |
| Processing Temperature Range | 200 - 230 °C |
As an accredited EVOH EVAL G156B factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | EVOH EVAL G156B is supplied in 25 kg sealed polyethylene-lined paper bags, protected from moisture and contamination. |
| Container Loading (20′ FCL) | 20′ FCL shipment of EVOH EVAL G156B resin, palletized, secured, and protected for safe, efficient transport. |
| Shipping | EVOH EVAL G156B is a non-hazardous ethylene-vinyl alcohol copolymer resin supplied in sealed, moisture-proof bags. It ships in standard dry containers or trucks, protected from humidity and direct sunlight. No dangerous goods declarations required. Keep pallets dry and handle with standard industrial equipment to prevent bag damage. |
| Storage | Store EVOH EVAL G156B in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep containers tightly sealed to prevent moisture absorption and contamination. Avoid storage near strong oxidizers or incompatible materials. Maintain moderate temperatures to preserve resin quality, and follow manufacturer’s recommended shelf-life guidelines. |
| Shelf Life | Shelf life: 2 years if stored unopened in original container, in a dry, cool environment away from direct sunlight. |
In commercial coextruded flexible food packaging for processed meat, fresh pasta, and portioned cheese, EVOH EVAL G156B is positioned as the central oxygen barrier layer in five-layer or seven-layer blown film structures. The compliance basis for direct food contact is FDA 21 CFR 177.1360 for ethylene-vinyl alcohol copolymers and Commission Regulation (EU) No 10/2011, with overall migration testing conducted under EN 1186-1:2002 and specific migration limits for hydrolysis-derived substances reviewed against Annex II restrictions. In a typical five-layer film with total thickness between 50 µm and 90 µm, the G156B layer is added at 3–8 wt% of total film mass, corresponding to a layer thickness of 3–6 µm, while maleic anhydride-grafted polyethylene tie layers occupy 4–8 wt% on each side at 2–4 µm and the sealing and structural layers are LDPE or LLDPE. Downstream production uses a coextrusion blown film line with screw diameters from 45 mm to 75 mm and L/D ratios between 24:1 and 30:1; the EVOH melt stream is maintained at 200–230 °C, and flat die temperature is held within ±5 °C across the die lip to prevent interfacial flow instabilities caused by viscosity mismatch between G156B and polyolefin melts. Pellet drying before extrusion is mandatory at 80–100 °C with dew point below −30 °C for at least 4 h to reduce moisture below 0.3 wt%, because residual moisture produces gels, lens-shaped voids, and degraded oxygen transmission rate performance. The terminal product types include vacuum skin packs for fresh red meat, modified-atmosphere lidding films for pasta and cheese, and flow-wrap films for bakery products; field failure on packaging lines is most commonly observed as delamination at the PE/tie interface when the tie layer drops below 2 µm or when die-lip buildup disrupts layer distribution, causing intermittent oxygen transmission rate values measured by ASTM F1927 to exceed spoilage thresholds.
Thermoformed retort trays for ready meals, pet food, and cook-in-bag substitutes place G156B under simultaneous thermal load and hydration, which is the main process conflict for ethylene-vinyl alcohol copolymers. The regulatory package includes EU 10/2011 overall migration limit of 10 mg/dm², FDA 21 CFR 177.1360, and retort validation according to ISO 17665-1:2006 for moist heat sterilization. In seven-layer sheet with PP skin layers and maleic anhydride-grafted PP tie layers, the G156B barrier layer is compounded at 1.5–4.0 wt% of total sheet mass, or 5–12 µm within a 350–800 µm sheet, with the exact ratio determined by post-forming corner thickness and target oxygen transmission rate after retort. Sheet extrusion is run on a tandem flat-die line with die width 1,200–1,600 mm and a barrier melt pump maintaining G156B melt temperature at 205–225 °C. Thermoforming is performed on plug-assisted machines with sheet surface temperature 150–185 °C; G156B displays a comparatively narrow forming window because excessive sheet temperature above 190 °C leads to barrier-layer thinning at tray corners below 2 µm, while insufficient temperature below 145 °C generates microcracks in the EVOH layer that raise oxygen transmission rate after retort. Post-process quality control uses ASTM F1927 at 23 °C and 85% RH, and production records show that a tray with acceptable dry-state oxygen transmission rate measured by ASTM D3985 commonly exhibits a post-retort increase of one order of magnitude or more after 121 °C for 30 min if the G156B layer is below 5 µm or if the PP/tie layer moisture barrier is insufficient. Terminal product types include single-serve ready meal trays, retortable pet food bowls, and shelf-stable infant meal containers; delamination at the tie/EVOH interface after cooling is the predominant manufacturing failure, traced in plant audits to inadequate tie-layer melt temperature control and to die-lip oxidation residues.
| Application segment | Compliance framework | Test method designation | G156B addition ratio / layer thickness |
|---|---|---|---|
| Flexible food film | FDA 21 CFR 177.1360, EU 10/2011 | ASTM F1927, EN 1186-1:2002 | 3–8 wt%, 3–6 µm |
| Retortable thermoformed tray | FDA 21 CFR 177.1360, EU 10/2011, ISO 17665-1:2006 | ASTM F1927, ASTM D3985 | 1.5–4.0 wt%, 5–12 µm |
| Automotive fuel tank shell | EPA 40 CFR 86.1813, CARB LEV III, SAE J1681 | SHED, pressure decay | 2–5 wt%, 0.05–0.30 mm |
| Cosmetic tube / bottle | EU 1223/2009, REACH EC 1907/2006, FDA 21 CFR 177.1360 | ASTM D3985, EN 1186-1:2002 | 4–8 wt%, 10–25 µm |
| Aseptic paperboard carton | FDA 21 CFR 176.170, EU 1935/2004, EU 10/2011 | ASTM F1927, ASTM F904 | 1.5–3.0 wt%, 5–10 µm |
| Pharmaceutical blister web | USP <661.1>, USP <671>, Ph. Eur. 3.2.2, FDA 21 CFR 211.94 | ASTM D3985, ASTM F1927 | 5–8 wt%, 15–25 µm |
In six-layer coextrusion blow molding of high-density polyethylene fuel tanks for gasoline and flex-fuel vehicles, EVOH EVAL G156B functions as the hydrocarbon permeation barrier layer; its selection is linked to flexural crack resistance under vehicle vibration and to processability at high parison shear. Regulatory compliance is driven by EPA 40 CFR Part 86.1813 evaporative emission measurement using sealed housing for evaporative determination, by CARB LEV III zero-fuel evaporative emission requirements, and by SAE J1681 for hydrocarbon permeation of fuel system components. The G156B layer is commonly specified at 2–5 wt% of total multilayer wall mass, which translates to 0.05–0.30 mm in a wall stock of 5–10 mm; adjacent maleic anhydride-grafted HDPE tie layers are 0.15–0.40 mm each, and an internal regrind layer consumes 30–50% of wall thickness. The blow molding cell is built around a 6-layer accumulator head with separate extruder streams for HDPE, regrind, tie, and G156B; EVOH melt temperature is limited to 200–225 °C, and residence time above 225 °C is kept below 10 min to avoid gel particle generation that causes barrier-layer interruptions and fuel permeation spikes. Blow mold clamp force for a mid-size fuel tank shell is commonly in the range of 800–1,500 t, with parison programming adjusted to limit die swell mismatch between HDPE and G156B; wall-thickness mapping after molding is verified by ultrasonic gauging, and tanks are subjected to pressure decay testing at 0.05–0.10 bar over 1 h for leak detection. Terminal product types include passenger car fuel tanks, lawn tractor tanks, marine outboard fuel cells, and canister-free small-engine tanks; field failure modes are usually pinhole leaks at pinch-off seams where EVOH layer continuity is disrupted by improper parison weld temperature, which is controlled above 190 °C at the pinch line. Published data for the specific permeation coefficient of G156B in ethanol-containing fuel blends is limited; approval testing for flex-fuel applications therefore relies on SAE J1681 permeation coupons with CE10 and CE85 fuels rather than extrapolation from dry gas permeation.
Cosmetic laminate tube and extrusion blow-molded bottle production exploits G156B primarily as a buried barrier layer against fragrance and oxygen ingress while maintaining high-gloss surface optics on squeeze tubes and rigid containers. The regulatory basis is EU 1223/2009 for cosmetic packaging compatibility, FDA 21 CFR 177.1360 for the polymer itself, and REACH EC 1907/2006 for monomer and SVHC reporting; sensory and global migration testing are conducted under EN 1186-1:2002 where the tube is marketed for incidental oral contact. In a five-layer laminated tube wall of 200–350 µm, G156B is added at 4–8 wt% of total wall mass, corresponding to 10–25 µm thickness between 5–10 µm tie layers of maleic anhydride-grafted polyethylene; the outer LDPE and inner LLDPE sealant layers account for the remaining mass. Production is either tandem extrusion lamination of the tube sleeve and side seam welding or continuous coextrusion blow molding of bottles with parison temperature at 190–215 °C; G156B must be pre-dried below 0.3 wt% moisture at 80–100 °C because trapped moisture forms microvoids at the tie/EVOH interface during side-seam bonding. The limited processing window arises during side-seam welding: if welding temperature dips below 170 °C, the barrier layer does not fully fuse at the overlap, leaving a channel for fragrance loss, and if temperature exceeds 220 °C, oxidation-induced gel specks appear along the seam. Terminal product types include retinol serum tubes, whitening toothpaste tubes, sunscreen bottles, and mascara laminate tubes; inline quality control measures seam thickness by optical profilometry and barrier continuity by ASTM D3985 at 23 °C and 0% RH on flattened tube samples.
When G156B is selected to replace aluminum foil in aseptic paperboard cartons for UHT milk, plant-based beverages, and liquid broths, the barrier layer is applied by extrusion coating or extrusion lamination onto corona-treated paperboard, and the critical trade-off is the loss of oxygen barrier at high relative humidity versus the elimination of foil cracking during flexure. The compliance package includes FDA 21 CFR 176.170 for paper and paperboard components in contact with aqueous and fatty foods, EU 1935/2004 for food contact materials, EU 10/2011 for the plastic layers, and ISO 22000 for aseptic packaging line hygiene. In a standard carton structure of 200–300 g/m² liquid packaging board, the G156B layer is applied at 5–10 µm, which is 1.5–3.0 wt% of total package mass after lamination; 10–20 µm of LDPE on both sides provides moisture sealing and adhesion, and 5–10 µm of maleic anhydride-grafted polyethylene tie resin is used between paperboard and G156B. Extrusion coating lines run at 300–600 m/min with melt temperature 180–230 °C and die widths up to 2,000 mm; the primary production challenge is maintaining 2–5 N/15 mm adhesion strength between G156B and tie layer as measured by ASTM F904, because insufficient corona treater output below 40 dyne/cm on the paperboard surface produces intermittent delamination and pinholes at crease lines. Terminal product types include one-liter UHT milk cartons, plant-based beverage packs, liquid stock cartons for foodservice, and aseptic soup bases; the critical operational boundary is that G156B is not a moisture barrier, so if the LDPE layer falls below 10 µm on the product side, oxygen transmission rate at 85% RH increases by more than one order of magnitude according to ASTM F1927, producing spoilage in high-water-activity liquids.
In pharmaceutical blister packaging for moisture- and oxygen-sensitive solid dose formulations, EVOH EVAL G156B is incorporated as a buried barrier layer in coextruded base webs where polyvinyl chloride provides thermoformability and PCTFE or high-density polyethylene provides moisture protection. Regulatory compliance is established under USP <661.1> for plastic materials of construction, USP <671> for container performance, Ph. Eur. 3.2.2 for plastic containers and closures, FDA 21 CFR 211.94 for drug product container closure systems, and FDA 21 CFR 177.1360 where the polymer is used in packaging materials. The G156B layer is added at 5–8 wt% of total base web mass, or 15–25 µm within a 250–400 µm coextruded sheet; tie layers of 10–15 µm are necessary because direct PVC/EVOH adhesion is insufficient after thermoforming. Flat-die extrusion is performed on clean-room lines with melt temperature 190–215 °C, chill roll temperatures 15–30 °C, and line speeds 50–150 m/min; thermoform-fill-seal blister machines run at 12–60 cycles/min with forming temperatures 140–170 °C. The main process conflict is that corner thinning in deep-drawn cavities below 2 mm radius reduces the G156B layer to less than 5 µm, generating oxygen transmission rate values above 1.0 cm³/(m²·day·atm) at 23 °C and 50% RH as measured by ASTM D3985, which is unacceptable for oxidation-prone actives. Terminal product types include cold-formable duplex and triplex blister base webs for antihypertensives, proton pump inhibitors, and vitamin D3 softgel lidding films; the incompatibility with high-moisture autoclaving and with direct steam sterilization of the formed web is a stated operational boundary because G156B loses barrier performance irreversibly after prolonged hydration above 80% RH at 40 °C.
On blister lines, inline vision systems monitor base web layer distribution by near-infrared scanning, and off-line oxygen transmission rate is sampled according to ASTM F1927 at 25 °C and 60% RH; batch-to-batch variation in G156B melt flow rate should be controlled within ±0.5 g/10 min per ISO 1133-1:2022 to avoid motor load fluctuations during flat-die coextrusion. Published data on the specific oxygen transmission rate of G156B after thermoforming at cavity depth-to-diameter ratios above 0.5 remains limited, and pharmaceutical converters therefore qualify each cavity geometry through permeation mapping rather than assuming uniform barrier from flat film data. The production-scale failure mode most frequently documented is die-lip buildup at the PVC/EVOH interface caused by thermal degradation of the PVC skin, which transfers to the G156B layer as surface drag and creates optical haze bands; this is mitigated by setting the coextrusion feedblock temperature at 185–200 °C and maintaining die lip cleaning intervals below 8 h.
Competitive EVOH EVAL G156B prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615380400285 or mail to sales2@liwei-chem.com.
We will respond to you as soon as possible.
Tel: +8615380400285
Email: sales2@liwei-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Kuraray’s EVAL G156B is a high-ethylene ethylene-vinyl alcohol copolymer supplied as translucent pellets for coextruded barrier structures. The resin carries a nominal ethylene incorporation of 47 mol%, which places it between mid-barrier grades such as E105B and higher-flexibility grades used in deep-drawn containers and tubes. Melt flow rate is reported at 5.5–6.0 g/10 min under 210 °C and 2.16 kg load according to ISO 1133-1:2022; density is 1.12 g/cm³ under ISO 1183-1:2019; and the melting point is approximately 158 °C under ISO 11357-3:2018. Oxygen permeability for a 20 µm film at 20 °C and 65 % RH is typically cited as 0.8 cm³·20 µm·m⁻²·day⁻¹·atm⁻¹ using coulometric detection per ISO 14663-2 or ASTM D3985. The principal difference from lower-ethylene EVOH grades is a reduced absolute gas barrier in exchange for improved stretch, flex-crack resistance, and tolerance to humidified processing.
Thermal degradation of EVOH is autocatalytic above 230 °C, releasing acetic acid and generating gel particles that disrupt layer uniformity in thin barrier films. For G156B, barrel zones in a single-screw extruder with an L/D ratio of 24:1 to 30:1 are normally set from 180 °C at the feed throat to 220–230 °C in the metering and pump sections; adapters and flat dies are held at 220–235 °C. Melt temperature measured at the die exit should remain below 240 °C. Residence time above 230 °C must be minimized by avoiding oversized extruders, low-screw-speed operation, and dead-end flow paths. Chrome-plated or nitrided screw and barrel surfaces reduce stagnation and corrosion associated with liberated acetic acid.
Screw design influences gel formation. A single-stage barrier screw with compression ratio 2.5:1 to 3.5:1 and a low-shear helical mixer is preferred over high-shear dispersive mixing elements. For a 40 mm extruder, metering depth is typically 2.5–3.5 mm to limit shear heating. Vented barrels are generally not used with EVOH because volatile acetic acid at processing temperature is corrosive to vacuum systems and does not remove bound moisture effectively.
Pre-drying in a desiccant dryer at 80–90 °C for 4–6 h to a residual moisture content below 0.1 % by weight is required when bulk material has been exposed to ambient relative humidity above 60 %. Splay, microvoids, and gel particles are commonly traced to moisture contents between 0.2 % and 0.5 %. The grade should be purged with LDPE before shutdown; contact with PVC, PVDC, or acetal residues at processing temperature is to be avoided because halogenated species and aldehydes accelerate discoloration and gelation.
In a five-layer cast film line producing PP/tie/G156B/tie/PP, the barrier layer is generally maintained at 3–10 µm within a total film thickness of 50–120 µm. Layer thickness control in the die is more stable with G156B than with lower-ethylene grades because the higher melt flow rate reduces interfacial shear stress at the die lip. However, the widened viscosity gap against PP requires tie resins with melt flow rates in the 2–6 g/10 min range to maintain layer encapsulation. Edge trim regrind is limited to 20 % in food-contact structures unless migration testing confirms compliance.
Barrier values for EVOH are not intrinsic constants; they depend on thickness, temperature, and moisture plasticization. G156B is normally evaluated at 20 °C and 65 % RH with a coulometric sensor per ASTM D3985. Under those conditions the oxygen transmission rate is approximately 0.8 cm³·20 µm·m⁻²·day⁻¹·atm⁻¹. When the film is conditioned to 90 % RH, the oxygen transmission rate increases because water disrupts interchain hydrogen bonding in the vinyl alcohol segments; the relative shift is more pronounced for 27 mol% ethylene grades than for 47 mol% ethylene G156B. This does not make G156B a better barrier at 90 % RH in absolute terms, but it narrows the performance difference between grades when the package is exposed to high-humidity distribution conditions.
Specimens for oxygen transmission testing should be conditioned at 23 °C and 50 % RH for at least 48 h unless the application requires direct measurement at 85 % RH or 90 % RH. Thickness normalization assumes inverse proportionality, but this is not fully linear below 10 µm because of interfacial effects in coextruded film. For retort applications, a polypropylene outer layer and adhesive tie resin must remain intact to limit moisture ingress during 121 °C steam processing. The EVOH layer is typically placed behind 15–30 µm of PP and a tie layer of 3–5 µm; post-retort oxygen barrier recovery depends on residual moisture and layer delamination. Published data for this specific configuration is limited; final package oxygen ingress should be measured on the formed container under ASTM F1307 or an equivalent whole-package method.
In extrusion blow molding of oval and F-style containers from 250 mL to 1000 mL, G156B is processed as a 5–10 µm internal barrier layer between HDPE or PP and a maleic anhydride-grafted tie resin. The resin is typically run at die temperatures of 220–230 °C, with blow-up ratios from 2.0:1 to 3.5:1. The higher ethylene content reduces die-line microcracking at pinch-off seams, a failure mode observed on lower-ethylene grades when pinch compression is excessive. Continuous-layer parison programming with a 1.0–1.5 mm die gap provides uniform barrier distribution in shoulder and sidewall regions. Regrind addition in non-food bottles is limited by the barrier layer’s moisture sensitivity and should not exceed 30 % unless documented by leak and drop testing under ASTM D2463 or ISTA 3A.
Intermittent multilayer parison formation places a different demand on melt strength than cast film. G156B has lower melt strength than HDPE; therefore, parison programming must compensate for diameter swell and sag. Die swell values of 1.4–1.8 are typical at shear rates of 100–500 s⁻¹ in spiral mandrel dies, but the exact value depends on die geometry and melt temperature. Layer encapsulation of EVOH must be monitored after each die rebuild; interruptions in the barrier layer as small as 5 µm can increase oxygen ingress by orders of magnitude in neck and pinch-off regions.
Thermoformed barrier trays and cups produced from PP or PS sheet commonly use EVOH layers of 5–15 µm. When a converter replaces a 27 mol% ethylene grade with G156B, the oxygen barrier of the sheet falls from near 0.08 to 0.8 cm³·20 µm·m⁻²·day⁻¹·atm⁻¹, so the EVOH layer thickness or total sheet thickness must be increased to meet a given shelf-life target. The offsetting benefit is reduced microcracking at corners and flanges during plug-assisted forming at draw ratios above 1.5:1. Mechanical property comparisons follow ASTM D638-14 tensile testing and ASTM F392 Gelbo flex testing; G156B demonstrates higher elongation at break and substantially lower pinhole formation after repeated flexing at 4 °C. The grade is therefore selected for chilled distribution packaging where flexural damage during transport and retail handling is the dominant failure mode rather than steady-state oxygen diffusion.
Sheet extrusion with G156B requires a coextrusion feedblock or multiplier die designed for high-viscosity barrier resins. The melt pump between extruder and die is set to a pressure of 10–20 MPa to maintain layer thickness uniformity. For PP/EVOH/PP sheet, surface temperature is typically 150–170 °C and mold temperature 20–40 °C. The plug assist should be heated to 90–120 °C to avoid local thinning of the barrier layer at the bottom corners. Plug-assist forming at draw ratios above 2.0:1 can reduce barrier layer thickness in the corner by 40–60 % unless plug geometry and temperature are controlled. G156B resists corner thinning better than lower-ethylene grades because of higher elongation at break, but barrier mapping of formed trays should still be performed by sectioning and measuring oxygen transmission of cut samples. Whole-tray oxygen transmission is determined with ASTM F1307; acceptance criteria often require oxygen ingress below 0.05 cm³/package·day·atm for oxygen-sensitive products, although target values vary by product weight and shelf-life.
| Grade | Ethylene content | Melt flow rate | Oxygen permeability | Typical role |
|---|---|---|---|---|
| EVAL L171B | 27 mol% | 3.2 g/10 min | 0.08 cm³·20 µm·m⁻²·day⁻¹·atm⁻¹ | Maximum oxygen barrier; moisture-sensitive; flex-crack-limited |
| EVAL H171B | 38 mol% | 1.6 g/10 min | 0.33 cm³·20 µm·m⁻²·day⁻¹·atm⁻¹ | Intermediate barrier and processability |
| EVAL G156B | 47 mol% | 5.5–6.0 g/10 min | 0.8 cm³·20 µm·m⁻²·day⁻¹·atm⁻¹ | Moderate oxygen barrier; improved flex-crack resistance and draw tolerance |
Table values are representative published datasheet figures; current manufacturer documentation should be consulted for production specifications and lot-specific data.
Food-contact suitability is governed by 21 CFR 177.1360 and, for the European Union, by Regulation (EU) No 10/2011 as amended; final multilayer structures require migration testing under the EN 1186 series and, if applicable, EU No 321/2011 for infant food. Overall migration must not exceed 10 mg/dm² of food-contact surface for general foods, or 60 mg/kg for infant food. G156B should not be dry blended with amine-based processing aids or amine-containing color concentrates because residual amines accelerate thermal yellowing and gel formation during coextrusion. Storage is recommended at ambient temperature below 30 °C and relative humidity below 60 % in unopened, moisture-proof packaging; opened material should be consumed within 8 h or re-dried before use.
