Rigid plastic packaging producer Greiner Packaging has teamed up with printing inks and coatings provider Siegwerk, as well as Krones on a recycling initiative for polypropylene (PP) and polystyrene (PS) cups. 

The partners have demonstrated the potential of advanced recycling facilities to process direct-printed PP and PS cups. 

The initiative saw the use of hot caustic washing, a standard process for polyethylene terephthalate bottle recycling, which effectively deinks and converts rigid containers into high-quality white recyclates without compromising the ink formulation or print design. 

These tested containers were considered to be non-recyclable by some Design for Recycling Guidelines. 

The hot caustic washing process is being increasingly implemented by recyclers who are working with polyolefin and PS rigid streams. 

The initiative's findings are crucial for the development of a more efficient and sustainable circular packaging economy, according to the companies. 

The project has brought to the forefront the importance of reevaluating the impact of printing inks and coatings on the recycling process.  

The partners are advocates for the adoption of the test standard published under DIN SPEC 91496. 

This perspective is aligned with the paper recently released by the European Printing Ink Association.

Last month, Greiner partnered with dairy products company Yaza to introduce its traditional Mediterranean labneh product in sustainable packaging.