“Debonding on Demand”: The Solution to the Recycling Challenge?

To reduce the amount of plastic in packaging, companies are increasingly turning to hybrid packaging made of plastic and cardboard materials bonded together. However, this composite material often hinders recyclability. A research project involving various Fraunhofer Institutes aims to make the material recycling of hybrid packaging feasible for the first time using a new approach.

A composite of cardboard and plastic makes it possible to reduce the plastic content of packaging by up to 80 percent while ensuring product protection and stability. However, it is precisely this material mix that can become a problem in the recycling process. “Even if the individual components of hybrid packaging are highly recyclable, they are often difficult to separate mechanically. Adhesives, too—if chosen incorrectly—can cause problems during recycling,” explains Nicole Ludat, Group Leader of Materials Testing and Monitoring Technology at Fraunhofer IVV.

Dr. Christiane Otto, Materials Testing and Monitoring Technology, Fraunhofer IVV, adds: “On the one hand, the recycling and sorting processes for plastic, paper, and metal are very different. On the other hand, separating hybrid packaging is often considered uneconomical—even in cases where it is technically feasible.” One current approach is to encourage consumers to separate materials manually. The plastic yogurt cup and aluminum lid are then supposed to go in the yellow bag, while the cardboard sleeve with the packaging design goes in the paper recycling. But this currently works in only about 20 percent of all cases. The result: mis-sorting and contamination that affect the quality of the recyclates. The demand for sustainable packaging solutions that can be recycled using today’s sorting and recycling technology is correspondingly high. The Fraunhofer DEBO-Pack project aims to provide a solution.

The DEBO-Pack project is based on the principle of “debonding on demand,” meaning an adhesive bond that can be selectively broken. This is triggered by an external factor—such as moisture, temperature, or mechanical stress—which is activated after use. “The packaging would then no longer need to be separated by consumers or using complex technology; instead, in the best-case scenario, it separates on its own,” explains Nicole Ludat. This way, the materials would be reliably separated even before sorting and could be fed directly into existing recycling processes.

The development of suitable adhesives plays a key role in “debonding on demand.” This is because the adhesive must remain stable throughout the product’s service life and dissolve selectively under defined conditions. “One example of such a trigger is an increase in temperature combined with moisture. This would be suitable for refrigerated foods, for instance, but it also shows that we need application-specific solutions,” says Christiane Otto. A complex challenge, then.

The three-year project will run until April 2027, with Fraunhofer IFAM, Fraunhofer IBP, and Fraunhofer UMSICHT serving as partners. With support from industry consultants, such as those in mechanical engineering, the team is developing a demonstrator solution. For this, there is an initial production concept on a pilot plant scale (larger than a laboratory experiment, smaller than industrial production), which is to be scaled up later. The project focuses on cup- or tray-like packaging for refrigerated foods.

The first DEBO-Pack packaging demonstrators will be on display in various designs at interpack 2026. During a workshop with industry partners, they were already evaluated from various perspectives, such as manufacturability and sortability and recyclability, and initial opportunities for optimization were identified.

“Debonding on Demand” could significantly increase the recycling rate of hybrid packaging in the future if it can be scaled up industrially. The project team is confident: “We believe the DEBO-Pack packaging holds great promise, and in our view, the project results can be easily applied to other applications,” explains Nicole Ludat.