VTT and Alpek Polyester joined forces to scale up and test an innovative PGA plastic barrier solution. The project addressed the challenge of keeping CO₂ inside soft drink bottles while ensuring full recyclability, demonstrating a new approach for the food and beverage industry.
Key facts
Carbonated soft drink companies need an effective, cost-efficient CO₂ barrier for plastic bottles. Traditional multi-material barriers typically disrupt PET recyclability.
VTT and Alpek Polyester collaborated to scale up a production process patented by VTT for a recycling-compatible PGA (Polyglycolic acid) plastic barrier layer.
The project successfully demonstrated the technical viability of the PGA barrier at pilot scale. It enabled the use of more affordable raw materials while maintaining excellent technical performance.
Alpek Polyester is the largest integrated producer in the polyester industry in the Americas, servicing customers all over the world using its global network of manufacturing entities. As the core business of the major petrochemical enterprise Alpek, founded in 1975 in Mexico, the company focuses on continuous innovation and sustainability.
High performance meets recyclability
PGA is an advanced bio-degradable solution for rigid and flexible food and beverage barrier packaging. A PGA polymer layer can be used as a high-performance barrier to oxygen or carbon dioxide and it can be washed away during the PET recycling process. This retains the recyclability of PET plastics.
For carbonated soft drinks, extending shelf life is critical; losing carbon dioxide causes the drinks to go flat and triggers expensive freight returns to bottling plants. Traditional barrier materials effectively trap gases but prevent the bottle from being recycled. PGA solves this by washing away safely during the recycling process, enabling a circular solution that keeps the fizz in the bottle and the plastic in the recycling loop.
From concept to pilot-scale production
The cooperation began when VTT presented its PGA concept at an industry conference. Antonio Garza, Global Vice President of Technology at Alpek Polyester, reflects:
“We happened to be in discussions with our customers that were in the quest for an improved, recyclable CO₂ barrier. So, our customer need and VTT’s concept were a perfect match.”
Over a five-year period, the partners worked closely to scale and refine the production process. The scaling project involved converting raw GA monomers into PGA plastic through industrial chemistry pilot runs, with advanced chain extension polymerisation conducted at VTT’s facilities in Tampere.
“We were able to significantly simplify the process using our expertise in polymerisation and pilot-scale operations. Furthermore, the process allows for the use of lower-purity, low-cost raw materials, making the solution an economically viable option without compromising performance,” explains Mika Härkönen, Professor of Practice at VTT.
Shared expertise and successful trials
Throughout the collaboration, VTT provided Alpek Polyester with:
Dedicated facilities for piloting and the production of necessary material quantities for customer trials
Specialised expertise in polymerisation and chain extension
Analytical capabilities and creative engineering for adapting existing processing equipment to meet the project's specific milestones.
The culmination of the project was the successful manufacture of finished PGA material in 50–100 kilogram batches, which were shipped to the US. There, Alpek conducted testing and trials in the manufacture of PET bottles.
Kevin Harrison, Global Technical Marketing Director at Alpek Polyester, emphasises that the permeation performance of the PGA barrier was exceptionally good.
“The high performance allowed for less material to be used in the bottle design, which actively addressed the economic requirements of the brands,” Harrison notes. He also highlights the exceptionally collaborative atmosphere, with Alpek’s experts working closely with the VTT research team on-site in Finland.
“In my experience, VTT had very mature technical professionals, with a clear customer orientation, and the ability to creatively adapt the processing assets to the project’s requirements,” Harrison notes.
The collaboration with VTT has been one of the very best we have had with a third-party research institute, and we are open to future initiatives with VTT.
The future of PGA in food packaging
Although Alpek successfully tested the material and validated its performance, a changing business focus meant they ultimately did not commercialise the PGA solution. Consequently, the intellectual property rights to the PGA technology were transferred back to VTT in 2025.
Despite halting commercialisation on their end, Alpek reflects highly on the joint effort and the realities of leading-edge R&D.
“We know that not every project is going to be a home run instantly, but it’s crucial to keep pursuing differentiation and innovations. From my perspective, the collaboration with VTT has been one of the very best we have had with a third-party research institute, and we are open to future initiatives with VTT,” Garza says.
Ultimately, the technical viability of the solution was fully proven at Technology Readiness Level 6, demonstrating that the VTT-developed process could seamlessly produce repeatable, pilot-scale quantities. For VTT, the returned IPR opens up new avenues.
“Beyond carbonated soft drink bottles, we believe that the PGA material holds tremendous potential in the wider food packaging sector as a dense film that keeps oxygen out, extending the shelf life of food while maintaining the sustainability of the packaging stream,” concludes Jouni Lattu, Technology Solution Sales Lead at VTT.
