Plastic recycling can only become truly circular when it is possible to separate plastic flakes based their chemical composition. For recycling perfect purification of our plastic waste is essential. Not only are there many different types of plastic that can be used for the production of everyday products. Each product – from lids, to shampoo bottles or plastic bags – has its own special recipe which makes recycling plastic difficult. Hence, if the flakes don’t have the exact same properties remelting them into new plastics will result in the loss of the good properties of the plastic and in value. The researchers aim to develop a way through which plastic can be recycled on such a specific recipe basis. The difficulties are how to recognize the various types of plastic flakes and subsequently how to extract the targeted or desired flakes from a mixture.

In order to develop a cheap and efficient solution, that can be massively used when ready the researchers use available ‘low’ technologies for measurement. To be able to recognize the specific recipe of a plastic flake the researcher is using infra-red spectroscopy scanning the various flakes. By comparing the plastic properties with the IR spectra the researcher aims to build a fingerprint library for each type of plastic. 

When plastics are recycled they are shredded to a very small size so they are very pure and not contaminated with another type of plastic. However, when we sort on this small scale we need to deal with a huge amount of flakes at the same time which asks for high resolution, accuracy and efficiency of the extracting process. Using a technology which is similar to our ink jet printer, using super small water jets instead of ink jets, the researcher is able to target the desired flakes because it is precisely controlled, separating wanted flakes from the rest. He is building a giant water droplet printer which can be controlled as a normal printer.