Fast and efficient sorting for multilayers

The Pellenc ST company, leader of the Work package 2 in CIMPA project, is a French manufacturer of intelligent and connected sorting machines for the recycling value chain. With an increasing turnover of 52M€ in 2021 and 250 employees, it is a key actor that enhances innovation, and brings industrial solutions all over the world. Its Near-Infrared (NIR) Detection technology, included in the brand-new Mistral+ Connect, is perfectly tailored to sort Multilayer structures.

In order to be recycled, post-consumer multilayer (ML) films need to be recovered separately from conventional PE or PP outlets in material recovery facilities. Sorting is then a key step to make the recycling of post-consumer packaging films sustainable and provide a valuable stream to recyclers. Both material recognition with NIR and Watermark detection will be used to tackle this challenge.

Successful achievements using NIR-Based Detection

After gathering samples from film producers such as BARBIER, LEGAYTECH and EVERSIA, Pellenc ST could adjust its detection settings with the use chemical analysis of ML structures and chemometrics algorithms

Then, in order to classify multilayers, Pellenc ST used the Mistral + Connect that had all the assets designed for this purpose:

è The NIR spectrometry reads the composition of all detectable layers

è The Turbosorter stabilizes products on the belt and makes the film ejection reliable

è A metal sensor can detect the presence of aluminum foils

The main achievement of this analysis was a very efficient sorting on PE/PA and PE/PET structures and an efficient inductive detection on metallized structures. For each of these categories, final batch purities were between 80 and 90% in one sorting step on real post-consumer batches provided by Paprec. All this work ended up with a ready-to-use ML sorting recipe applicable on Mistral + Connect.

The future of ML sorting will need watermark designs

The detection of the NIR-undetectable designs such as PE/EVOH, PE+AlOx… remains unresolved. Fortunately, the watermark detection proposed by Filigrade might fill the gaps. That is why, Pellenc ST will implement the prototype of Filigrade on the “Emerging technology line” at its new innovation center inaugurated the 28^th of June 2022. Trials on watermarked products are programmed in Q4 2022: It is expected that the combination of NIR and Watermarking will address all sorting challenges with a fast, real time solution for Multi-layers.