According to a study published in the journal Nature, researchers at the University of Birmingham have created a new type of recyclable bio-based resin that can be 3D printed in high definition before being recycled back into its constituent parts and repeated.
The study demonstrated that high-resolution 3D printed structures may be made entirely using bio-based feedstock. When the items have reached the end of their useful life, they can be recycled using an almost entirely closed-loop system.
As part of the investigation, the researchers accomplished two printing ‘recycles’ using the material, but they believe that more may be done. To maintain the resin’s curable qualities, only a little amount of photoinitiator is required when reprinting it.
Recyclable bio-based resin for 3D Printing
The fundamental ingredients, typically epoxies or acrylics, are derived mostly from petrochemical feedstocks. Although there has been considerable improvement in the use of more sustainable resins derived from biomass, their recyclability remains limited since they rely on irreversible connections formed when the resin solidifies. To break these bonds, more chemicals must be added at each level, resulting in a’snowballing effect’ in which the only way to recycle the material is to produce more of it.
In contrast, the Birmingham-led team has succeeded for the first time in producing a photopolymer resin that can be printed at high resolution but can then be broken down to its constituent parts, recycled, and reprinted with only a small amount of photoinitiator added to maintain the material’s curing properties.
“Our approach is an important step away from relying on 3D-printable resins made from petrochemicals, which cannot be efficiently recycled. While we still have improvements to make to the properties of the new resin, this research opens up exciting new avenues for development.”
– Professor Andrew Dove, lead researcher, Birmingham’s School of Chemistry
Lipoic acid, a naturally occurring fatty acid molecule that is widely available as a dietary supplement, serves as the process’s feedstock. The scientists combined two monomers derived from lipoic acid to create a resin that could be recycled back into the monomers or directly back to the original molecule.
The material could be utilised in companies that use fast prototyping to evaluate goods before they are mass produced. Although the material is now more flexible than what is routinely used in industry, future uses may include automobile parts, medicinal and dental components, and even jewellery design.
“Enabling recycling within the light-mediated 3D printing industry is essential since it is a rapidly expanding method for materials production. We now have the prospect, with our technology, to help ensure that recycling becomes a built-in feature of 3D printing.”
– Professor Josh Worch, co-lead researcher Assistant, Birmingham’s School of Chemistry
The University of Birmingham Enterprise has filed a patent application for the recyclable bio-based resin and its usage in 3D printing.
