PETmachine
By Andrew Gregory. Posted
The doom and gloom over climate change and ecological collapse does have one silver lining: the high numbers of plastic bottles that we’re currently throwing away into landfill, or rivers and seas, are a brilliant potential source of 3D printing filament. Polyethylene terephthalate, or PET as it’s abbreviated, is strong, light, non-reactive, and is a barrier to oxygen, which is the molecule that among other things enables bacteria to turn beer into vinegar. It’s an incredibly useful material in food packaging for all these reasons, and in its modified form of PETG, it’s also widely used in 3D printing. Igor Tylman has built a machine that can reliably turn empty PET bottles into 3D printing filament, potentially turning rubbish into gold. There’s no place on Earth that doesn’t have an excess of plastic bottles, so this technology really could lower the entry barriers to 3D printing for many people. It’s pretty simple: the rotating bottle is continuously sliced into a single thin strip which runs through a heater to shape it into a consistent 1.75mm wide filament.
Get started with Raspberry Pi – everything you need to know to start your journey!
The machine itself is 3D-printed, and the electronics and build instructions are available from Igor’s website. The G at the end of PETG stands for ‘glycol-modified’, which is a process that makes the PET easier to work with; without this modification, any printer using this recycled filament will need an all-metal hotend capable of reaching 270°C, on top of which the makers recommend using a dual-drive extruder.

Features Editor Andrew trawls the internet for Cool Stuff while keeping the magazine running smoothly.
Subscribe to Raspberry Pi Official Magazine
Save up to 37% off the cover price and get a FREE Raspberry Pi Pico 2 W with a subscription to Raspberry Pi Official Magazine.
More articles
Unusual tools: degaussing tool
In the simplest form, a degaussing tool is a coil of wire that generates an alternating magnetic field that demagnetises ferrous metals.
Read more →
RP2350 Pico W5 review
It’s Raspberry Pi Pico 2, but with a lot more memory.
Read more →
Retro 3D-printed Typeframe PX-88
Distraction-free writing on a piece of new, vintage kit – it’s like the olden days, but better.
Read more →