At Washington State University, a team of researchers is working on the issue of upcycling, i.e. this method of transforming waste products or matTurning PLA into 3D printing resin
materials that are no longer used in other materials or objects. They seek to give a second life to products, in this case anything made from PLA. The team has developed a simple method to transform the polymer into 3D printing resin and thus recreate an object with greater added value.
This upcycling trend is becoming more and more widespread, even more so when combined with additive manufacturing. 3D technologies are the ideal way to bring waste or an object that is no longer useful back to life. Yu-Chung Chang and his team were interested in PLA, a natural and biodegradable plastic. But one that can only fail under the right conditions. He explains: “It is biodegradable and compostable, but once you examine it, it turns out that it can take up to 100 years for it to break down in a landfill. In reality, it still creates a lot of pollution. We want to make sure that when we start producing PLA at million ton scale, we know how to deal with it.
The researchers therefore developed a rapid, catalyst-free process to recycle PLA. The principle is relatively simple: they came to break down the chain of molecules that form the polymer into monomers. To do this, they used aminoethanol, a fairly inexpensive organic compound. Decomposition would take about two days. The team actually used a metaphor that speaks to everyone:
If you want to rebuild a Lego castle in a car, you have to break it down brick by brick. That’s what we did. Aminoethanol precisely cuts PLA into a monomer, and once it’s back into a monomer, the sky’s the limit because you can repolymerize it into something stronger.
Once in the monomer state, the researchers were able to reconstruct the plastic into a light-curing liquid form, creating a resin compatible with stereolithography printing. Upon completion of the manufacturing process, the team claims to have achieved thermal and mechanical properties equal to or better than commercially available resins. They hope to replicate these same results with PET, another plastic that poses even more problems when it comes to recycling as well as a widely used material (often found in water bottles for example). You can find out more HERE.
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