This Wood-and-Paper Byproduct "Ink" Could Deliver Sustainable, Recyclable 3D Printing

Researchers from Helmholtz-Zentrum Hereon and VESC Studio have developed a water-based "ink" for 3D printing that, they say, is fully recyclable — and which can be made from industrial waste as simply as adding water.

"We wanted to demonstrate that waste-derived materials like lignin can meet the technical demands of modern 3D printing while improving sustainability," explains co-lead author Maria Balk of the team's work in sustainable 3D printing. "To do this, we transformed an industrial waste product into a water-based 3D printing ink that can be fully recycled simply by adding water."

That waste product: lignin. "Lignin is one of the most abundant components of wood, yet largely underused," says corresponding author Francesca Toma. "Turning it into a fully recyclable material shows how waste can drive innovation in an industry that urgently needs sustainable solution. Industrial waste streams are an untapped opportunity."

The "ink" itself is around 70 percent lignin, mixed with water to create a substance that can be squeezed through a 3D printer's nozzle for additive manufacturing without heat or chemical treatment — solidifying over time. As well as reducing industrial waste through its production, the team found that the ink itself could be recycled to turn printed objects back into more ink.

"One of the most exciting findings is that the printed objects can be recycled multiple times through rehydration without losing performance," Balk explains. "This is still very rare in additive manufacturing and could offer a realistic pathway toward circular manufacturing in 3D printing, where materials can be reused instead of discarded, significantly reducing waste and CO₂ emissions. We are now interested in scaling the process and exploring real-world applications, particularly in areas where low-energy processing and recyclability are crucial."

The team's work has been published under open-access terms in the journal ACS Sustainable Chemistry & Engineering.