“Our technology helps to close material cycles”

Plastics recycling: how the IOSB’s expertise in bulk material sorting and digitalization is contributing to increasing sustainability and resource efficiency

Prof. Längle, what is the link between the technologies found in the inspection and optronic systems business unit and climate protection?

Thomas Längle: Our skills in bulk material sorting have already been used in recycling for many years. It doesn’t matter whether the material is used glass, construction waste or plastic – separating the different substances as effectively as possible is a key prerequisite when it comes to producing high-quality recyclates. With regard to plastics in particular, we need to do much better in terms of recycling if we are going to achieve the general target of climate neutrality by 2050. According to current estimates, around 50 million tons of CO2 are produced as part of the plastics value chain in Germany alone each year – the majority of which is down to the fact that a good half of all used plastic is simply sent for thermal recycling, i.e., burnt. Not only would other recycling methods be more sustainable, they are also becoming more and more attractive from an economic point of view as a result of CO2 pricing.

That’s why Fraunhofer is championing the vision of a circular plastics economy.

Exactly. The aim is to significantly increase the proportion of materials that are recycled. Where that isn’t possible, it’s important that plastic waste is at least turned into a secondary source of raw materials through chemical recycling, replacing the need for fossil raw materials. This would keep the carbon within the economic cycle instead of releasing it into the atmosphere as CO2. The Fraunhofer lighthouse project Waste4Future is developing a comprehensive approach here and our expertise is playing a key role in several ways.

How exactly?

Firstly, we are developing a digital twin that will map the processes and material flows comprehensively and interoperably to enable the plastics cycle to be evaluated in a transparent and digital manner. This will allow optimization across the board and the best recycling approach to be defined for each different part of the material flow – taking technical, economic and ecological factors into account. We are also making further developments to sensors and sorting technology. Commonly used sensors have weaknesses – for example, when distinguishing different black plastic materials or if parts have an internal structure. One area on which the project is focusing is therefore multi-sensor data fusion, which when combined with machine learning methods will enable materials to be identified reliably and in real time.


Prof. Längle is spokesperson for the Inspection and Optronics Systems business unit and head of the Visual Inspection Systems department (SPR).

Annual report »We make AI fly«

The above interview is taken from our Annual report 2021/2022, which focuses on Fraunhofer IOSB's AI application expertise.


Inspection and Optronic Systems

Learn more about the fields of application and technologies of our business unit Inspection and Optronic Systems.