How milk jugs can make 3D printing cheaper

The solution to expensive 3D printing could be in your refrigerator right now.

With 3D printing, anyone with a 3D printer can make just about anything using a digital design and plastic filament. And while you can get simple open-source printers for surprisingly cheap (anywhere from $250-$500), one kilogram of the plastic filament can set you back between $30-$50. But there's one solution that might be sitting in your refrigerator right now: milk jugs.

Researchers at Michigan Technological University are looking to milk jugs as a way for 3D printing to gain more widespread use. To make this practical, the research group created the RecycleBot, a device that melts the plastic (after it has been washed and the labels have been removed) and turns it into a long, thin string of plastic filament. This way you cut out the recycling middleman or the landfill and turn your milk jugs into useful objects. The design for the RecycleBot is open-source and available here.

Of course, you get what you pay for. Milk jugs are made out of high-density polyethylene, which isn't ideal for 3D printing, but the team says that the disadvantages to using this type of plastic aren't overwhelming. The research team has used the process to make everything from lab equipment to golf tees and cell phone cases.

But the application of this process could be broader than people printing plastic trinkets in their garage.

"Three billion people live in rural areas that have lots of plastic junk," says Joshua Pearce, the project lead at Michigan Technological University. "They could use it to make useful consumer goods for themselves. Or imagine people living by a landfill in Brazil, recycling plastic and making useful products or even just 'fair trade filament' to sell."

Or maybe someone could mine the Great Pacific Garbage Patch.

Pearce says that it takes about 20 milk jugs to produce about 1 kilogram of plastic filament, which typically costs $30-$50.

Photo: Michigan Technological University

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