March 6, 2014
New Process Recycles Milk Jugs Into 3D Printer Filament
redOrbit Staff & Wire Reports - Your Universe Online
Not only is manufacturing goods using a 3D printer far cheaper than purchasing items, new research appearing in a recent edition of the Journal of Cleaner Production reveals that it can actually help preserve the environment.
The 3D printing process was very expensive when Charles W. Hull of 3D Systems Corp created the first working model in 1984, and while the costs have dropped dramatically over the past 30 years, the cost of purchasing plastic filament still needs to be factored in. The new study, however, shows how old milk jugs can reduce those expenses.
In their study, Michigan Technological University associate professor of materials science and engineering/electrical and computer engineering Joshua Pearce and his colleagues demonstrated that using milk jugs made from HDPE plastic to create the 3D printer filament actually uses less energy than conventional recycling of the beverage containers.
The milk jug was cleaned, cut into pieces and run through an office shredder. It was then sent through a device known as a RecycleBot, which turns waste plastic into 3D printer filament. When compared to urban recycling programs that collect and process plastic locally, the RecycleBot process required about three percent less power.
“Where it really shows substantial savings is in smaller towns like Houghton, where you have to transport the plastic to be collected, then again to be recycled, and a third time to be made into products,” Pearce said.
Under those circumstances, the energy savings soared to between 70 and 80 percent, and recycling your own milk jugs also uses 90 percent less energy than making virgin plastic from petroleum, the researchers noted.
In terms of cost, Pearce said that filament retails for between $36 and $50 per kilogram. By using recycled plastic, a person can produce homemade filament for 10 cents per kilogram. Even factoring in the roughly $300 cost of the RecycleBot, he said that there was “a clear incentive” to produce filament using recycled plastic containers.
However, the study authors also report that the HDPE plastic used in milk jugs is not ideal as a 3D printer filament component, as it shrinks slightly as it cools. Even so, this technology has reportedly drawn interest from the Ethical Filament Foundation, an organization seeking an environmentally friendly and ethically produced alternative production method to keep up with the demands of the expanding 3D Printing market.
“In the developing world, it’s hard to get filament, and if these recyclers could make it and sell it for, say, $15 a kilogram, they’d make enough money to pull themselves out of poverty while doing the world a lot of good,” said Pearce, who was the corresponding author and worked alongside Michigan Tech colleagues Megan Kreiger, Meredith Mulder, and Alexandra Glover on the Journal of Cleaner Production paper.
Currently, 3D printing is used in the fields of architecture, construction, industrial design, engineering, medical technology and even the fashion industry. Last month, NASA announced that it would be launching several formal programs to prototype new tools for future missions using the increasingly popular new manufacturing technique.
An Open Access version of the research paper is available here.