26 Aug 2019
waste sorting

Waste Sorting: Multi-Spectral X-ray Inspection Systems

InnospeXion has developed an on-line X-ray inspection system that can help waste sorting by differentiating between organic and inorganic waste, based on the atomic composition variation of the scanned items. This technology can help recover various materials that can be recycled, in this way reducing the amount of waste and minimizing unnecessary burning. Goal 12 strongly focuses on responsible production and consumption. Both of these aspects are tightly related to the waste that is generated as a result of various production activities, but also waste resulted from irresponsible consumption. The method of processing the resulted waste, and optimally minimizing it, can therefore significantly contribute to fulfilling Goal 12, more specifically target 12.5: “By 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse.


By minimizing waste and unnecessary burning, InnospeXion’s solution contributes to the reduction of CO2 emissions. Sorting stations based on human sorting are not only less precise than our solution, but they are also dangerous for the workers’ health. This is why there is a need for efficient automatic waste sorting systems.


The current sorting equipment on the market is based on machine vision, and this sorting technique is challenging due to the fact that they are only capable of surface scanning. This means that in case on bulk waste (the common storage method of waste), these systems are not efficient because they cannot see below the surface. A newer innovation of this technology is the combination of machine vision with X-ray scanning. Even though this combination improved the capability of waste sorting in terms of making it possible to scan deeper in the bulk of waste, the sorting part based on composition is still not covered by current technology.

This is precisely the gap that our product is filling. With multiple energy X-ray scanning, it is now possible to determine the atomic composition of different items, quantify it, and thereby sort the mixture into different categories.

waste sorting

The technology is unique and extraordinary because it can essentially automatically detect and differentiate between a fruit and a plastic bag between a big pile of mixed waste, and sort them into different categories. This sorting and categorization can be into organic-inorganic waste, plastics, metals, other materials, etc.

The upscaling potential of our product is high. The technology has been created to manage waste in bulk, in various industrial contexts. The nature of our solution, and the fact that it can determine the type of waste and categorize them in different categories means that it can be used with different purposes. One could sort industrial waste, but it can also be applied to sort domestic waste. What is more, the fact that it provides signals for various reject arrangements, it means that it can be combined and used complementary with pick & place robots, and it can be integrated with other sorting systems.


Even though the perception that X-rays are dangerous is still prevalent, with the help of correct shielding and use of the system, our solution is just as safe as any other machinery. Although multi-energy scanning is a new and innovative technology, through its previous implementation within the security sector, it has been demonstrated that with an appropriate protection cladding, it can withstand harsh environments such as a waste & garbage handling station, and it can be fast, reliable and robust.


Standard X-ray imaging can be useful when wanting to differentiate between very few and pre-established materials. Standard technology can, for instance, successfully display if an object is made of thicker material than another, but it cannot determine the type of material based on the atomic composition.

The multispectral X-ray technology can successfully do that. What is more, the system can do that by scanning waste at a speed up to 40m/min. Estimated sorting capacity is up to 10kg/s, and the system provides output to robots and sorting services.

Fig. 0 Oil  identified in a tray containing mixed materials.

Fig. 1 Copper material identified in a tray containing mixed materials.

Fig. 2 Steel material identified in a tray containing mixed materials.

This technology has been initially developed for security scanning, as part of a project in collaboration with Innovation Fund Denmark, involving InnospeXion ApS, DTU, Magnatek ApS, DIS A/S, KU, Exruptive A/S.

The application of the technology for waste sorting has been further developed by Innospexion.

Interested in finding out more about our waste inspection capabilities?