Researchers at UW-Platteville find way to convert spoiled milk into 3D printing plastic

PLATTEVILLE, Wis. (CBS 58) -Thanks to the research of two professors at UW-Platteville, there may truly be no reason to ever cry over spilled milk.

Chemistry Professor Joseph Wu and Mechanical Engineering Professor John Obielodan recently had a breakthrough in their efforts to use milk protein as a polymer 3D printers can use to create various molds.

Their research on the southwestern Wisconsin campus began before the COVID-19 pandemic when they were exploring whether different plant materials could be used to create plastics.

When the pandemic hit, they noticed farmers nearby had a problem: Milk demand had dried up, and much of the product was going to waste.

"Farmers' dairy companies could not deliver the goods," Obielodan said. "And they're perishable."

They found milk protein had the potential to give them the basics. As it curdled, the protein separated, and the solid part of the protein, casein, showed promised.

Still, it took lots of trial and error.

"We do it repeatedly, over and over, and I can't really put a number on it," Wu said. "Well, the first time is definitely not a success. It doesn't extrude out very well."

Wu suspected fats in the protein were mucking up the process. He used different solvents to separate the fats and settled on butanol; it worked well, and he found the smell to be more tolerable.

Sure enough, the fat-free protein worked much better. The protein can be converted into pellets or a powder that goes over to Obielodan's engineering domain.

The protein extract is blended with other materials to make spools of filament.

"[We] feel such a relief because we are actually doing research into the unknown," Wu said.

The development was enough to secure a U.S. patent for Wu and Obielodan earlier this year.

Still, they're not satisfied. Wu said he's still working to create a version of the protein that can be converted into plastic without being blended with other materials.

"There’s more chemistry that needs to be done," he said. "If we can print directly from milk protein, that would be great. That’s actually one of our visions."

While that research continues, Wu and Obielodan said their ultimate goal is to take their invention off campus.

"If we find an investor that is interested in buying the intellectual property rights, we will work with the person," Obielodan said.

Wu said seeing their invention one day help shift an industry would mean a lot, but what matters most to him is having a great lesson he can now teach.

"Using this project to demonstrate knowledge is powerful," he said. "We can actually use knowledge to help the community, and that is always close to my heart."