This submission was recognized by the ARC Sustainability Committee as a Best Technical Paper from the 2024 R2R USA Conference & Expo. See more content like this at this year's R2R USA, May 19–21 in Cleveland.
By Ana Lyra and Sheila Khodadadi
To help meet the global demand for sustainable flexible packaging solutions Terphane, now part of Oben Group, started the development of BOPEF films, in partnership with Avantium.
Avantium’s YXY® Technology catalytically converts plant-based sugars into FDCA (2,5-furandicarboxylic acid). The company’s FDCA Flagship Plant, opened in October 2024 in Delfzijl, Netherlands, with expected commercial launch this year, represents a major step forward in scaling this technology. Beginning in 2006, Avantium achieved the proof-of-principal for its YXY Technology, marking the start of its proprietary development to create plant-to-plastic solutions to produce 100% biobased polymers such as PEF (polyethylene furanoate) with what the company calls superior functional properties for food and beverage packaging applications, as well as for specialty films and textiles. With an annual production capacity of 5,000 tons of FDCA, the company’s FDCA Flagship Plant aims to prove the scalability of the YXY process and demonstrate the commercial applications of FDCA and its lead product, 100% bio-based polymer, PEF. Avantium says collaboration is a core element of its strategy. By working with industry-leading partners, Avantium aims to accelerate the adoption of sustainable technologies, and it has signed multiple long-term offtake agreements to supply FDCA and PEF to global brand owners, including Terphane for film production in the Americas.
Avantium’s commercialization strategy includes expanding production capacities through technology licensing, with the goal of empowering industry leaders to build larger plants. In 2023, Avantium signed a technology license agreement with Origin Materials and says it continues to expand its license portfolio. Later that year, Terphane signed with Origin Materials a multiyear capacity reservation agreement to purchase PEF for use in film applications, including food and beverage packaging and other industrial applications.
As previously noted, YXY Technology catalytically converts plant-based sugars (sucrose) into FDCA, the key building block for PEF (polyethylene furanoate). The FDCA production process involves:
Dehydration: Plant-based sugars are converted into RMF and HMF using a catalytic process.
Oxidation: The Furanic derivatives are catalytically oxidized to produce FDCA.
Purification: Impurities are removed to produce purified FDCA.
Melt polymerization: Purified FDCA and monoethylene glycol (biobased MEG) are polymerized to create the plant-based polymer, polyethylene furanoate (PEF), followed by a solid-state polymerization step to achieve the desired molecular weight for the target applications.
Processing: PEF can be further processed into different applications such as bottles, films, thermoforms, and textiles using the existing assets for PET (polyethylene terephthalate).
Mechanical and chemical recycling: PEF is adoptable with the existing sorting and recycling facilities and can be recycled mechanically and chemically using the same technologies that exist or are under development for PET recycling.
In the realm of advanced sustainable materials, releaf® (the official brand for Avantium’s PEF and a European Union trademark) emerges as a new bio-based polyester, with the following main aspects:
Bio-based: PEF is made from plant-based materials. Avantium’s FDCA Flagship Plant uses locally produced, commercially available first-generation feedstock: glucose from starch (wheat).
Recyclability: PEF can be recycled back to PEF using existing mechanical recycling assets and received endorsements on its fit with PET recycling streams. It is included in the Critical Guidance Protocol from the Association of Plastic Recyclers (APR) and has received an interim endorsement from the European PET Bottle Platform (EPBP) for recycling of multilayer PET/PEF packaging in the European bottle recycling market.
Mechanical strength: According to Avantium, PEF exhibits superior mechanical strength and thermal stability, which can lead to lighter and more durable packaging and therefore reduce the material usage.
Carbon footprint life cycle assessment (LCA): Avantium partnered with nova-Institut GmbH to perform a full LCA for the FDCA plant based on the YXY Technology. This assessment evaluated the potential environmental impacts of PEF resin and PEF bottle packaging solutions compared to conventional PET alternatives. The LCA results for releaf (PEF) show a 73% reduction in greenhouse gas emissions for 500 mL bottles compared to a conventional PET bottle and a 65% reduction in greenhouse gas emissions on resin level. By using renewable carbon sourced from plants, releaf temporarily stores carbon dioxide, contributing to climate change mitigation.
Barrier properties: PEF has superior CO2 and O2 barrier properties, which helps in preserving the freshness of food and beverages for a longer time. See below some examples of food packaging using the BOPEF film, including examples of mono-material structures with the packaging recycle ready:
PEF and PET are two polyesters with similar chemical structures that can be processed and recycled using the same assets. However, their thermal, mechanical, and barrier properties differ significantly. PEF, as a bio-based recyclable polyester, not only serves as an alternative to PET but also complements it, according to Avantium.
The superior barrier properties of PEF compared to PET can be attributed to its unique molecular structure. Gas permeability in polymers is governed by two factors: sorption and diffusion. PEF exhibits higher CO₂ sorption than PET due to the polar moment of its furan ring, which facilitates favorable interactions with polar molecules. However, the overall permeability is significantly reduced by the restricted local motions within the PEF structure, hindered furan ring flipping, and constrained carbonyl rotations, which limit the diffusion of small gas molecules. The lower permeability of PEF compared to PET is maintained in biaxially stretched samples and is enhanced by increased strain-induced crystallinity, reinforcing PEF’s barrier performance.
In terms of thermal properties, solid amorphous PEF has an improved ability to withstand heat (~10° C higher glass transition temperature than PET) and can be processed at lower temperatures (~30° C lower melting point than PET). PEF also demonstrates higher mechanical stiffness and strength compared to PET. These properties, combined with its superior barrier performance, according to Avantium, enable reducing the weight of packaging up to 20% while maintaining shelf life, aligning with ambitions to reduce packaging waste.
The study compared the physical properties of BOPET (biaxially oriented polyethylene terephthalate) and BOPEF (biaxially oriented polyethylene furanoate). The key findings are summarized in Table 2 below:
The data shows that BOPEF demonstrated superior mechanical properties compared to BOPET, with higher strength and impact resistance. Notably, BOPEF exhibited approximately 10 times higher oxygen barrier and three times higher water vapor barrier than BOPET.
After metallization, BOPEF maintained its barrier properties. The oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) for metallized BOPEF were 10 times and two times lower, respectively, than those for metallized BOPET.
These results indicate that BOPEF can potentially replace aluminum foil in packaging applications due to its enhanced barrier properties.
Both BOPET and BOPEF were corona-treated using dosage of 30.4 W.min/m² in air. The evaluation comparing the surface energy level throughout the time for both surfaces are shown at the graph at right.
BOPEF films exhibited higher surface energy than BOPET films, which is beneficial for printing and lamination processes. Additionally, BOPEF maintained its surface energy levels over time.
Both companies, Terphane and Avantium, conducted printing tests to evaluate BOPEF and BOPET film. Each test was conducted at the same time and same conditions, being the only variable the film substrate. On the table below is the summary of the printing tests.
The dot size was evaluated in BOPEF and BOPET samples printed at flexographic industrial printer using microscope. Both substrates (BOPEF and BOPET) had similar dot size: Wickoff ink varying from 70 to 80 µm, and Actega inks varying from 65 µm to 90 µm. No noticeable differences in printing quality were observed.
The ink rub test was with both BOPET and BOPEF printed samples rubbing it 250 times. After the test, the samples were examined for any ink removal, smudging, or wear. The performance of the printed BOPET and BOPEF were the same.
The ink adhesion performance was evaluated using different methods, being the “Tape 3M600, pull 45°” as indicated at the ASTM F2252. The method “Tape 3M610, fast pull” adhesion test is more indicative of what is tested for performance evaluation right after the printing process: Apply the tape 3M610 to the printed substrate with a lot of pressure and then pull the tape very aggressively. The last round of tests was done using multiple types of Siegwerk inks, including ester-, alcohol-, and nitrocellulose-based inks. At majority of ink adhesion tests performed, the results showed that BOPEF had similar ink adhesion performance as the BOPET, being the ink adhesion to BOPEF, in some evaluations, slightly better than BOPET.
The last group of printed samples from the previous table were laminated to foil/CPP laminate structure. Laminations were made using HB Fuller 4245/2282 adhesive applied at 2.2 lbs/ream and then dried at oven at 30° C for one week. Lamination bond was measured using a dynamometer. Results are displayed in the table below.
The resulting “tear” is the expected result, indicating that lamination bond is high causing the sample to tear or break. The lamination tests also indicated that BOPEF and BOPET had comparable performance being most of the results.
In addition to the primary metallization trials done by Avantium, Terphane also performed metallization trials. In Table 5 are the results for the trials, including OTR and WVTR results.
The Terphane metallization process of the PEF samples was conducted using the Bobst Metallizer K5000 Expert, applying the same parameters as those used for PET sample. The oxygen transmission rate (OTR) was measured at 25° C (77° F), one atmosphere, and 85% relative humidity using the MOCON Oxtran 2/22. The water vapor transmission rate (WVTR) was measured at 38° C (100° F), one atmosphere, and 90% relative humidity using the MOCON Permatran 3/34.
The metallized BOPEF sample using 3.0 optical density reached OTR results lower than 0.1 cm3 /m². day and WVTR equal to 1.0 g/m². day. With these levels of oxygen barrier and water vapor barrier, the metallized PEF can be used as a replacement for aluminum foil.
To do a further evaluation of the metallized PEF performance, the sample with 3.0n optical density were sent to 2 different converters and a 3-ply lamination structure PE/adh/met-PEF/adh/PET-ink was produced. In Table 6, the lamination bond, OTR, WVTR, hot fill pouch test and boiling test results are shown.
Laminated structure keeps low OTR and WVTR, especially for the Converter 2. Both lamination bond results were as expected: all samples tear for the Converter 1 and had delamination for the converter 2, with lamination bond of 117 gf/in measure. As the laminated structure of the Converter 2 didn’t have any primer applied to the PET, delamination happened as expected and ink transferred to the metallized side. For the Converter 1, additional tests were performed:
Hot fill pouch: A pouch was done with the laminated structure and filled with 50 ml of water, the pouch was then immersed in water at 90° C for 30 min followed for pouch immersion in cold water (25° C) for 5 min to mimic a thermal shock.
Boiling test – pasteurization: Cut 10 cm x 10 cm specimen and immersed in water at 95° C for 30 min.
The results showed that BOPEF maintained its integrity and did not delaminate, even under harsh conditions.
In collaboration with Bobst Manchester Ltd. and Brückner Maschinenbau GmbH, Avantium prepared metallized AlOx PEF films together with the PET films reference.
The results confirm the significant barrier properties improvement of met-PEF and PEF-AOx compared to met-PET and PET-AlOx. The adhesion test also showed no metal was removed from the PEF layer.
The results confirm the significant barrier properties improvement of met-PEF and PEF-AlOx compared to met-PET and PET-AlOx. Under the measured condition, the oxygen barrier improvement factor is approximately four times higher for metallized PEF compared to metallized PET, and about seven times higher for PEF-AlOx compared to PET-AlOx. Additionally, the water barrier is improved by approximately two to two-and-a-half times for metallized PEF and PEF-AlOx, respectively. The adhesion test showed that no metal was removed from the PEF layer meaning that the coating layer was not detected on the EAA tape test, and therefore no coating failure was observed.
Avantium’s releaf PEF is a 100% bio-based polyester, recyclable with a reduced carbon footprint. The data show its biaxially oriented film exhibits exceptional oxygen and water vapor barrier properties, making it an excellent candidate to replace PVDC and EVOH. When metallized, PEF-met offers 10 times the oxygen barrier and twice the moisture barrier of PET-met, making it a viable substitute for aluminum foil. █
van Berkel, J. G.; Guigo, N.; Kolstad, J. J.; Sbirrazzuoli, N. Biaxial Orientation of Poly(ethylene 2,5-furandicarboxylate): An Explorative Study. Macromol. Mater. Eng. 2018, 303, 1700507. https://doi.org/10.1002/mame.201700507
de Jong, E.; Visser, H.A.; Dias, A.S.; Harvey, C.; Gruter, G.-J.M. The Road to Bring FDCA and PEF to the Market. Polymers 2022, 14, 943. https://doi.org/10.3390/polym14050943
RCI’s scientific background report: „Case studies based on peer-reviewed Life Cycle Assessments – Carbon footprints of different carbon-based chemicals and materials“ (November 2023) | Renewable Carbon Publications
Ana Lyra is an R&D engineer for Terphane. She can be reached at analyra@obengroup.com.
Sheila Khodadadi, Ph.D., is a technical account manager at Avantium. She can be reached at sheila.khodadadi@avantium.com.
