Ink vs. recycling: Siegwerk, Wildplastic and TU-Hamburg partner on novel deinking tech

Dieter Gottschalk, Ingo Fehr and Jinyang Guo are together showcasing a plastic film.

09 Feb 2023 --- Siegwerk has partnered with German startup Wildplastic and the Hamburg University of Technology, Germany (TU-Hamburg), to increase the recyclability of plastic waste through deinking.

Inks on packaging can often be a hindrance to recycling, as the inks degrade during the recycling process and can contaminate the recyclates, leading to unpleasant odors or “unsightly” colors.

Deinking collected waste before entering the recycling process creates a higher potential for plastic to be recycled, as it prevents the packaging inks from contaminating the materials. The partners conducted initial trials of deinking plastics entering the recycling stream at the end of 2022 with successful results.

“We started this collaboration with Jinyang and the university about one year ago following our deep interest to find a solution for specific washing needs for highly challenging post-consumer plastic film materials in a small-scale batch operation,” says Dieter Gottschalk, Wildplastic co-founder.

LDPE is a common ingredient in packaging bubble wrap. Recycling LDPE
Wildplastics’ primary focus is sourcing low-density PE (LDPE) such as bubble wrap or food packaging. The company states the market collection incentive for LDPE is still limited since it cannot be widely recycled.

Wildplastic aims to change this by creating demand for this material and showcasing the potential of post-consumer LDPE recycling.

After collection, the plastic is transported to a recycling partner who washes, melts and processes it into granules. These recyclate granules are then sent to a production partner and used as a substitute for virgin LDPE material.

The substitute is used to create trash bags and mailbags. If the LDPE was deinked beforehand, a broader scope of applications might be possible. Even if the inks are partially removed, the opportunities for recycling are increased exponentially.

Ink decreases recyclability
Siegwerk supports Wildplastic in its initiative by providing the deinking chemistry and knowledge. For successful deinking to occur, a precise combination of the right ink chemistry, suitable deinking detergent and the right processes must be applied.

“Siegwerk as the producer of printing ink, can play an important role in this context since it brings the producer’s perspective to solve the problem in the beginning,” states Jinyang Guo from the Institute of Circular Resource Engineering and Management from TU-Hamburg.Ink on plastics often disrupts the recycling stream, decreasing recycling rates.

“Wildplastic has the ambition to benefit from deinking in their recycling activities in just a few months and brings in an industrial perspective,” adds Ingo Fehr, senior project manager at Siegwerk.

Partner perspective
The partners of the initiative say deinking is only through cross-industry collaboration that can make progress to increase the recyclability of plastics.

“From our project, we have learned that a successful circular economy only works by motivating all the stakeholders involved,” continues Guo.

The senior project manager at Siegwerk echos back to Guo that “the scientific perspective and the conscientiousness contributed by Jinyang helps us to maintain a fact-based and objective view. Not only in the design of experiments but also in the interpretation of results.”

Cleaning up plastics
According to the partners, of billions of metric tons of plastic produced worldwide, only about 9% are recycled, and about 12% end up in landfills. The rest can end up leaking into the environment, waterways and breaking down into harmful microplastics.

Wildplastic, in collaboration with communities of collectors, works globally to collect “wild” plastic from beaches, landfills and illegal dumpsites.

Siegwerk has been working on increasing the recyclability of its products. Last year, Henkel and Siegwerk developed an oxygen barrier coating for food packaging made from flexible monomaterial plastic for streamlined recyclability.

Edited by Sabine Waldeck

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