The plastic recycling process is more complex than it might seem.
Despite common thinking, the plastic bags it cannot be defined as a simple “material”. Inside there are different polymers, to which chemical compounds, fibers and pigments are added.
The combination of all these elements makes the separation of the plastic and the identification of the type it belongs to quite complex.
To facilitate the entire process, some researchers from the Department of Chemical and Biological Engineering at Aarhus University have managed to develop a camera system.
The cameras would be able to "see" the difference between 12 different types of plastic (PE, PP, PET, PS, PVC, PVDF, POM, PEEK, ABS, PMMA, PC and PA12), completely transforming recycling.
Recycling meets Artificial Intelligence
The Aarhus University study was published in the journal Vibrational Spectroscopy. Professor Mogens Hinge, the project director, explained the potential of the new camera system.
"With this technology, we can now see the difference between all types of consumer plastics and different high-performance plastics. We can even see the difference between plastics which are made from the same chemical building blocks, but which are structured slightly differently."
These are his words, which make us think of a clear improvement in the recycling process of plastic bags. The studied technology has already been tested on a pilot scale, and is expected to be implemented at PLASTIX and Dansk Affaldsminimering Aps in spring 2022.
“We use a hyperspectral camera in the infrared area and machine learning to analyze and classify the type of plastic directly on the conveyor belt. Plastic can therefore be separated into different types. It's a breakthrough that will have a huge impact on plastic separation."
Professor Mogens Hinge, project director at Aarhus University
Plastic recycling
Currently, plastics are separated using near infrared (NIR) technology; alternatively, a density test is used (floats / sinks in water).
Both methods are capable of separating some plastic fractions (ex: PE, PP and PET), but they do not have the same precision as Professor Mogens Hinge's new recycling technology.
Hans Axel Kristensen, CEO of the company PLASTIX – which collaborates on the project – confirmed the advantages of the new infrared system, stating that:
“The technology we have developed in collaboration with the university is nothing short of a game changer for our ability to recycle plastic. We can't wait to install the technology in our processing room and begin the long journey in earnest towards using 100% of plastic waste. "
Through new technology, it may be possible to effectively differentiate different types of plastic, paving the way for a safer and more environmentally friendly system.
