01How it works
How a bottle becomes filament
Six steps, from the ground to something you can hold.
Why only clear PET #1
ReSpool makes filament from clear PET #1 bottles, like water and pop bottles. Every bottle is checked for the #1 code before anything is heated, so other plastics stay out of the machine.
Never heated
PVC, code #3, is never heated because it releases chlorine gas.
Rough yields
- 2 L bottle
- about 20 m of filament
- About 300 m
- 1 kg of filament
02The six steps
Follow one bottle
Here is the path a bottle takes, from a cleanup bin to the printer.
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Step 1: Collect
We pick up litter at community cleanups and set aside clear plastic bottles, like water and pop bottles. Other recyclables are sorted for proper disposal.
- Keep
- Clear PET #1 bottles
- The rest
- Sorted for proper disposal
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Step 2: Sort
Each bottle is checked for the #1 code to confirm it is clear PET.
Never heated
PVC, code #3, is never heated because it releases chlorine gas.
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Step 3: Wash and dry
Bottles are washed, then dried fully. PET absorbs moisture, and moisture ruins filament.
- Moisture
- Dry fully before forming
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Step 4: Cut into a ribbon
The cap and label come off. Then the bottle is spiral-cut into one long strip, called a ribbon.
- Removed
- Cap and label
- Cut
- One long spiral strip
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Step 5: Form into filament
The ribbon is pulled through a heated nozzle on a Polyformer, an open-source machine the team builds and runs. It comes out as round filament and is wound onto a spool.
- Diameter
- 1.75 mm
- Check
- Measured with calipers
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Step 6: Print
The filament is printed into real objects that people can hold.
- Safety
- Not for food contact
Safety
Processing is supervised and ventilated.
Read more on the Safety and FAQ page.
03Get involved
Start at a cleanup
Every spool starts with bottles picked up at a community cleanup.
- Provided
- Gloves, bins, all the other cleanup equipment and refreshments
- Hours
- Volunteer hours are tracked and can be confirmed