How to turn plastic waste in your recycle bin into profit
12 Jan 2021, 00:39 GMT+10
People will recycle if they can make money doing so. In places where cash is offered for cans and bottles, metal and glass recycling has been a great success. Sadly, the incentives have been weaker for recycling plastic. As of 2015, only 9% of plastic waste is recycled. The rest pollutes landfills or the environment.
But now, several technologies have matured that allow people to recycle waste plastic directly by 3D-printing it into valuable products, at a fraction of their normal cost. People are using their own recycled plastic to make decorations and gifts, home and garden products, accessories and shoes, toys and games, sporting goods and gadgets from millions of free designs. This approach is called distributed recycling and additive manufacturing, or DRAM for short.
As a professor of materials engineering at the forefront of this technology, I can explain – and offer some ideas for what you can do to take advantage of this trend.
How DRAM works
The DRAM method starts with plastic waste – everything from used packaging to broken products.
The first step is to sort and wash the plastic with soap and water or even run it through the dishwasher. Next, the plastic needs to be ground into particles. For small amounts, a cross-cut paper/CD shredder works fine. For larger amounts, open-source plans for an industrial waste plastic granulator are available online.
Next you have a few choices. You can convert the particles into 3D printer filament using a recyclebot, a device that turns ground plastic into the spaghetti-like filaments used by most low-cost 3D printers.
Filament made with a 3D-printable recyclebot is incredibly cheap, costing less than a nickel per pound as compared to commercial filament, which costs about US$10 per pound or more. With the pandemic interrupting global supply chains, making products at home from waste is even more appealing.
The second approach is newer: You can skip the step of making filament and use fused particle fabrication to directly 3D-print granulated waste plastic into products. This approach is most amenable to large products on larger printers, like the commercial open source GigabotX printer, but can also be used on desktop printers.
Granulated plastic waste can also be directly printed with a syringe printer, although this is less popular because print volume is limited by the need to reloading the syringe.
My research group, along with dozens of labs and companies throughout the world, has developed a wide array of open source products that enable DRAM, including shredders, recyclebots and both fused filament and fused particle 3D printers.
These devices have been shown to work not only with the two most popular 3D printing plastics, ABS and PLA, but also a long list of plastics you likely use every day, including PET water bottles. It is now possible to convert any plastic waste with a recycling symbol on it into valuable products.
Furthermore, an “ecoprinting” initiative in Australia has demonstrated DRAM can work in isolated communities with no recycling and no power by using solar-powe