Recycling Plastic Into 3D Printing Filament Uses Less Energy Than Conventional Recycling


While 3D printing is becoming increasingly popular, the realization that it is expensive to buy the materials needed to print objects is starting to hit home. A spool of plastic filament costs around $30 and most projects use more than one spool, depending on the size.

A recent study, however, led by Joshua Pearce of the Michigan Technological University, may offer hope for 3D printing enthusiasts who are looking for more economical, as well as more environmentally friendly materials to print with. The study shows that recycled plastics, such as milk jugs and empty shampoo bottles that can be recycled, can be turned into plastic filament. Recycling these materials into 3D printing filament also uses less energy than conventional recycling. Good news for both the pocketbook and the environment.

Pearce’s team did an analysis on a standard milk jug made from HDPE plastic. After cleaning it and cutting it in pieces, they ran it through an office shredder and then a RecycleBot, a device that turns plastic trash into filament.

Compared to a conventional recycling program, turning plastic into filament at home uses about 3 percent less energy, state the team. “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,” said Pearce, in which case the energy savings reaches a staggering 70-80 percent. Recycling your plastic milk jugs also uses about 90 percent less energy than it does to make new plastic from petroleum.

While HDPE tends to shrink slightly as it cools, for projects that are just made for fun, or testers, that doesn’t really matter. This new recycling technique has grabbed the attention of groups such as the “Ethical Filament Foundation,” which works with organizations around the world to encourage the manufacturing of recycled 3D printing filament.

The “Plastic Bank” also has taken an interest in the recycling of plastics for 3D printing. Their purpose is to reduce the waste of plastics, and repurpose it in new ways – such as 3D printing. Its mission has been to remove as much plastic as possible from foreign places such as the ocean. Their goal to “reduce poverty through 3D re-purposing social and ocean bound plastics” fits in with Pearce’s research as well.