Design evolution

Last year, 50 billion cartons were collected for recycling, totaling 1.2 million metric tons. This represents just over one-quarter (26 percent) of the volume of cartons sold globally based on aggregated consumption data, including from all carton converters, and reflects the quantity sent to recyclers, which is higher than the volume effectively recycled.

To put it simply, a significant gap exists between the volume of cartons sold and the volume recycled. Responding to this disparity, the carton industry has set out to achieve a 90 percent collection rate and a 70 percent effective recycling rate in the European Union by 2030. (The collection rate is measured as the weight of packaging sent to recyclers divided by the weight of packaging put on the market. The collection rate does not consider the losses of material that occur during the cleaning and recycling steps, while the effective recycling rate does deduct these losses.)

A systemic change is needed to enable this, from improving collection and recycling systems to growing recycled material use and applications to evolving the design of packaging to facilitate recycling.

Defining recyclability

Much of this change starts with how we approach recycling. Key stakeholders in the packaging industry are leading the way by moving away from definitions centered on “technical recyclability” to those that consider “recycling demonstrated in practice and at scale.”

For example, a 1-liter Tetra Pak carton package typically is made of approximately 70 percent paperboard, 25 percent plastic and 5 percent aluminum to protect the product inside. All these materials, including the aluminum, are recyclable where efficient waste management and recycling infrastructure exists.

However, recognizing the need to advance the practicality and scalability of recycling, we are dedicated to decreasing the share of virgin, fossil-based plastics and aluminum in these cartons and to increasing the renewable share of cartons (i.e., paper and plant-based polymers) while continuing to keep food safe and available for consumers.

Marking a significant breakthrough in this journey, Tetra Pak completed a 15-month commercial technology validation of a polymer-based barrier replacing the aluminum layer, and, shortly after, progressed with a consumer test of cartons featuring a fiber-based alternative barrier—an industry first.

What’s wrong with aluminum?

The aluminum layer currently used in food carton packages for ambient distribution protects the contents inside, keeping products safe and preventing spoilage. It does so by offering an impenetrable barrier to light, UV rays, microorganisms and other contaminants.

Despite these benefits, the aluminum barrier in aseptic packaging poses challenges. Even though it is thinner than a human hair, sourcing and processing this material requires complex and energy-demanding processes, therefore contributing one-third of the greenhouse gas emissions linked to base materials used by Tetra Pak. Moreover, the technologies to extract aluminum from postconsumer cartons are lacking on a large scale.

What’s the alternative?

With a mission to reduce climate impact and accelerate recycling, both in practice and at scale, a commercial technology validation started in Japan in late 2020 using a polymer-based barrier to replace the aluminum layer.

The initiative highlighted the implications for the value chain. It also confirmed adequate oxygen protection for vegetable juice while enabling increased recycling rates in a country where recyclers favor aluminum-free cartons.

We then tested a new fiber-based barrier in close collaboration with some of our customers while incorporating these learnings. A first pilot batch of single-serve packs featuring this industryfirst material was put on shelf for a commercial consumer test in the first half of this year, with further technology validation scheduled for later this year.

Early results suggest substantial CO₂ reduction when compared with traditional aseptic cartons that typically are made from approximately 70 percent paperboard, 25 percent polyethylene and 5 percent aluminum in the case of a 1-liter carton while maintaining comparable shelf life and food protection properties. More broadly, this concept increases the attractiveness of postconsumer carton packages for paper mills because of the higher paper content.

Even when considering advanced recycling solutions, such as making new plastic pellets out of polyAl, the nonfiber component of a carton package, a fiber-based barrier would provide higher purity and interest in the recycling market for polyethylene than a package that has an aluminum layer. Recycling tests performed on packaging material including the fiber-based barrier showed properties of the recycled polyethylene (PE) as being closer to other recycled PE without aluminum in the material input for recycling.

Responding to demand

This initiative underscores our approach to design for recycling, where increasing the paper content is critical while supporting end-user expectations. Based on our recent global consumer research, approximately 40 percent of respondents mentioned that if packages were made entirely from paperboard and had no plastic or aluminum, that would motivate them to sort for recycling even more.

Furthermore, our 2021 Sustainable Packaging B2B research revealed that wasteful packaging is a key concern for food and beverage manufacturers and retailers, and that “securing sustainability in the business” is among their top priorities—surpassed only by “adapting to consumer needs.”

What to watch out for?

Transformational and collaborative innovation is critical to accelerate recycling in practice and at scale, as changes such as shifting from an aluminum layer to an alternative barrier have implications that affect the full system—from the packaging material composition through the opening/closure systems to the sealing technology. In fact, the aluminum layer in aseptic cartons has a functionality reason—protecting food from oxygen and light, acting as a barrier—and a technical reason, because it is responsible of the sealing of the cartons in the filling machine. Therefore, it is critical to use the full product life cycle as the compass guiding any innovations.

What’s next?

The fiber-based barrier currently is suitable for dairy and similar products as it protects the contents of the carton from light and oxygen. We plan to extend this to other product categories.

We have a well-defined road map, including various stages that will help us realize the company’s ambition of creating the world’s most sustainable food package, a carton that is fully made from responsibly sourced renewable or recycled materials, is fully recyclable and carbon-neutral. Next steps will include working on the future generations of alternative barrier solutions while reducing plastics and finding further options to maximize the fiber content of our packages.

To keep the innovation engine running, we are investing 100 million euros ($ 99.04 million) per year and will continue to do so over the next five to 10 years, with a research and development focus on simplifying material structure and increasing the renewable content of our packages.

We have a long journey ahead of us, but with the support of our partners and a strong determination to achieve our sustainability and food safety ambitions, we are well on our way.

The author is product director of packaging materials, alternative barriers, at Tetra Pak, based in Sweden. More information is available at www.tetrapak.com.