Fraunhofer IVV works on a wide range of projects, and Dr Büttner highlights one that addresses some of the challenges of packaging materials that contain recycled materials. The institute recently developed a sensor based sealing tool for inline process controls for packaging machines.
"When sealing processes take place in packaging, especially those packs containing a higher percentage of recyclate, strict checks are necessary. The tool enables the user to filter out packs that haven't been sealed to a high standard directly in the machine."
But the use of recyclates also bring technological challenges as they may work differently on packaging machines.
"How can trays and films with recyclate be processed? New technologies working well with the new materials are needed. There are different solution approaches and technological advances, but we have not managed to bring all of this together as a compact or combined solution. Achieving this is an exciting challenge I'm very much looking forward to working on," Dr Büttner says.
“With recycled materials, decontamination can be a major challenge. With the current collection methods and processes, there are many sources that enable contaminations to enter the recycling streams, which have to be eliminated with great effort."
Fraunhofer IVV is active in the area of developing diagnostic tools and sensor systems that recognise deviations from the norms in materials, a challenging field, as Dr Büttner explains.
“Sometimes certain recurring contamination types are known. These can be addressed with targeted sensors, analytical and diagnostic tools, but sometimes contaminations do not fit the brief. This is where intelligent sensor systems are needed – most likely combinations of sensors – and checks need to take place whether a new material is fit to use in packaging or not."
A smelly problem
Seemingly simple problems such as smell can cause a challenge, as Dr Büttner explains.
“Plastics are used to package food, as well as products with strong smells, such as washing powders. Lots of different odours seep into the plastics – getting rid of those smells is a major challenge. This leads to the question: Should we pre-sort certain types of packaging, or design them differently in the first place? The scent doesn't necessarily have to be added into the washing powder and then be flushed away down the drain. Maybe there is a different way of achieving the same result."
Design for recycling
Finding solutions for the issue of recyclability and keeping food safe is another pressing issue.
“For years, companies have worked with multilayer models in order to achieve perfect barrier properties, but at times these are not easily recyclable. With a view to recycling, we need to develop new concepts, such as multilayer products that can be delaminated."
Dr Büttner sees a complementary role for chemical recycling. "With current collection methods and the way packs are designed I see no way around the use of chemical recycling, simply for decontamination reasons. But in some cases, mechanical recycling can work just as well. Recycling for PET bottles, for example, has been very successful as a closed system. Ideal might be, in any case, combinations of sorting and purification technologies…guided by intelligent monitoring and control."
Keeping food safe should remain a key factor, as Dr Büttner points out in conclusion.
"I see a danger that this very strong desire, also in politics, to want a lot really quickly leads to hastily put-together pseudo solutions that end up making the whole issue a lot more difficult, for example when hastily jumping into bio-based and renewable raw material applications that have not undergone a thorough quality check. It is important to keep an eye on functionality and safety. If they create more food waste, then nothing is gained."