Waste Plastic can be convert into a resin for 3D printing

PULLMAN, Wash. – A team of researchers at Washington State University has developed a new method of recycling polyactic acid (PLA), a plastic often used in filament, plastic silverware and food packaging.

The simple and efficient method converts PLA into a high-quality resin, which can then be used in 3D printing.

“We found a way to immediately turn this into something that’s stronger and better, and we hope that will provide people the incentive to upcycle this stuff instead of just toss it away,” said Yu-Chung Chang, a postdoctoral researcher in the WSU School of Mechanical and Materials Engineering and a co-corresponding author on the work.  “We made stronger materials just straight out of trash. We believe this could be a great opportunity.”

About 300,000 tons of PLA are produced annually, and its use is increasing dramatically. It doesn’t break down easily and can float in fresh or salt water for a year without degrading. PLA is also rarely recycled because like many plastics, when it’s melted down and re-formed, it becomes weaker and loses value.

“It’s biodegradable and compostable, but once you look into it, it turns out that it can take up to 100 years for it to decompose in a landfill,” Chang said. “In reality, it still creates a lot of pollution. We want to make sure that when we do start producing PLA on the million-tons scale, we will know how to deal with it.”

In their study, published in the journal, Green Chemistry, the researchers, led by Professor Jinwen Zhang, developed a fast and catalyst-free method to recycle the PLA, breaking the long chain of molecules down into simple monomers – the building blocks for many plastics.

Once the PLA was broken down to its basic building blocks, the researchers rebuilt the plastic and created a type resin that is commonly used as printing “ink” for 3D printers. When it was used in a 3D printer, the product showed equal or better quality than commercially available resins.

While the researchers focused on PLA for the study, they hope to apply the work to polyethylene terephthalate, which is more common than PLA, has a similar chemical structure and presents a bigger waste problem.

They have filed a provisional patent and are working to improved the process.

Source: Washington State University