PLA sorting for recycling. Experiments performed at the National Test Centre Circular Plastics (NTCP)

Sustainably produced bioplastics can contribute to the transition to a circular economy, certainly if there is maximum recycling. An earlier (2019) CE Delft study concluded that it may be interesting from both an economic and a sustainability perspective to sort out PLA packaging in a plastics sorting machine and then recycle it mechanically or chemically. In this project the theoretical analysis was put to a practical test in a PLA sorting trial at the National Circular Plastics Testing Centre (NTCP) in Heerenveen. The main question addressed was:

How well can 3D PLA be sorted out from Dutch PMD waste with a higher volume fraction of PLA, and how does the higher share of PLA affect other sorted plastic fractions like PET?

The main conclusions are:

  • 73-78% of the waste PLA can be sorted out for recycling.
  • The PLA fraction is 91-95% pure.
  • PLA contamination of the PET, PE and PP fraction can be significantly reduced by prior removal of the PLA (from 0.91-0.96% to 0.02-0.03% contamination with sorting of the PLA before PET).

Based on the literature and interviews with stakeholders it was then also explored how the sorted material can be mechanically or chemically recycled.