Testing Demonstrates Feasibility of Sorting PLA From Mixed Waste Streams

Tomra Recycling and Total Energies Corbion, a PLA producer, released results of testing to confirm that PLA can be sorted from other plastic wastes.

The tests were conducted in August on a Tomra Autosort system using near-infrared sensor technology. In the first test, two types of trays were correctly classified by the system as PLA. Then, partially crushed trays were run with a mix of background waste material. In the first trial, all but one partial tray part were correctly sorted into the ejected fraction. In the second trial run, 30 PLA trays were sorted, all of them correctly ejected into the PLA fraction. One PET bottle was oversorted into the PLA fraction, where it had been carried by one of the trays.

For test 2, the machine was set to eject PET materials and sort PLA trays into the other, waste background fraction. One PLA tray was carried with an ejected PET object, all others were successfully sorted into the other fraction. In all cases, the Tomra system correctly identified PLA material, they only ended up in the wrong fraction if they were physically pulled by an ejected material.

According to Total Energies Corbion, results confirm that PLA can be easily sorted from municipal plastics waste using existing sorting equipment, suggesting that the increased use of PLA will not negatively impact existing PET reprocessing.