Bio-based and more sustainable circular food packaging
Europe uses 50 million tons of plastic every year, with nearly half of that being used for all types of packaging. Currently, only about 32% of this plastic waste can be and is being recycled, while the rest is destroyed after just one use. Developments in the PRESERVE project aim to replace existing packaging with bio-based alternatives, while continuing to ensure a high level of product protection and still supplying high-quality materials for further use (upcycling), material recycling or for composting after use.
To start with, the protective properties of the innovative packaging materials are improved using bio-based barrier coatings for bioplastics, paper and cardboard substrates, as well as via electron beam treatment and microfibrillar reinforcement. For more effective composting, enzymes are incorporated into the bioplastics. Another approach involves delaminating multilayer composites through the enzymatic degradation of an intermediate layer, which allows them to be recycled separately. The recyclates recovered this way are reprocessed wherever possible in one or more production cycles, e.g. as flexible or injection-molded cosmetic packaging or as a fiber material. As a result of the versatility of these end-of-life options, materials, flexible and rigid packaging types, and their compatibility with different processes, more than 60% of plastic packaging on the market could be replaced with bio-based materials. The participation of several leading companies in the consortium also helps to maximize this long-term potential for substitution.
Development of bio-based materials
Fraunhofer IVV can build on years of research in the field of bio-based barrier coatings, which will now be further developed, scaled up and tested in applications in the PRESERVE project until they are ready for market. One area of development consists of whey protein-based coatings, which are expected to achieve an oxygen permeability of < 1 cm3/m2 d bar. This type of protein coating can also be used as a functional interlayer in laminates. The interlayer is broken down by enzymes during the recycling process, freeing up the different types of plastic, which can then be recycled separately.
In a second area of research, bio-based adhesives are being developed that can either be applied as hot melts or as solvent-based laminating adhesives. Some of the raw materials used for adhesive development are also obtained from the enzymatic degradation of packaging materials, such as PLA.
Bio-based packaging in practical application tests
Combining bio-based substrates, adhesives and coatings intelligently is expected to yield properties similar to those found in commercial packaging. Processes that are required to produce several types of packaging prototypes, such as thermoformed trays, stand-up pouches or drink cartons, will be scaled up and developed further. These prototypes will be characterized, assessed in user acceptance tests, and then evaluated in terms of their life cycle and safety aspects.
The new packaging solutions made from renewable raw materials and the upcycling applications based on them will be used to further contribute to the circular economy of packaging, not only providing optimum protection for food and drinks, but also for our environment and its limited resources.