This gadget recycles plastic water bottles into 3D printing filament (and it is open supply)


Here is a prototype of the Polyformer.

Picture: Reiten Cheng

Plastics, ecologically talking, have gotten a fairly unhealthy repute over time, typically fairly deservedly so.

Nonprofit ocean conservation group Oceana experiences that two rubbish vans price of plastic enters the world oceans each minute. That is 33 billion kilos of plastic getting into the oceans yearly. Mapping service Arcgis has charting knowledge that exhibits there are 5 main patches of plastic-covered ocean protecting 20 million sq. kilometers (7.72 million sq. miles). That is sufficient plastic to blanket Alaska, Texas, California, Montana, and New Mexico (America’ 5 largest states by space).

The US Environmental Safety Company experiences that the US generated 35.7 million tons (roughly the burden of 17.8 million Tesla Mannequin 3 autos) price of plastic. Total, solely 8.7% of the plastic produced is recycled, however that price differs primarily based on the kind of plastic as a result of various kinds of plastics have very completely different chemical properties.

PLA, or polylactic acid, is the commonest sort of plastic utilized in 3D printing. It is a very easy-to-use materials, it adheres to the print mattress nicely, and is fairly sturdy for a lot of makes use of. It deteriorates within the solar and might be brittle, however the overwhelming majority of things I’ve made have been printed with PLA as a result of it really works nicely in extrusion 3D printers.

PLA has some pluses ecologically, as nicely. Slightly than being created from fossil fuels, it is created from renewable sources like corn, cassava, sugarcane or sugar beet pulp. PLA can be biodegradable, though there are some particular footnotes to that declare. It would not compost nicely. About half of the fabric decays over time, however the remainder can stay for tons of and even hundreds of years. You do not need to dump PLA in landfills for a similar motive. However PLA does incinerate somewhat properlyleaving no residue or poisonous fumes.

In the case of recycling, PET (or polyethylene terephthalate), is one thing of a winner. In keeping with the EPA, almost 30% of all PET has been recycled. That is massively vital as a result of PET is the fabric used to make plastic water bottles and jars. In keeping with the College of Southern Indiana, People use 2.5 million plastic bottles each hourmost of that are thrown away after use.

A modified variant of PET, referred to as PETG (polyethylene terephthalate glycol-modified), can be fairly well-liked in 3D printing. PETG replaces the ethylene glycol in PET with cyclohexanedimethanol, which provides six further carbon atoms. This makes the molecular construction much less tight, and that permits the plastic to soften at a decrease temperature.

PETG will soften at about 230 levels C. In contrast, PET (the water bottle plastic) will soften, however at temperatures nearer to 280 levels C. That is close to the highest finish of the temperature vary for many hobby-level extruders on 3D printers.

The truth that PET can technically be 3D printed opens up a easy query: How can we flip water bottle plastic into 3D printable filament?

Reiten Cheng, an industrial designer who simply graduated this spring from Pasadena’s ArtCenter Faculty of Design, appears to have a solution. And it is open supply. He calls it the Polyformer.


Polyformer heated extrusion mechanism

Picture: Reiten Cheng

The thought for the Polyformer is straightforward. Use a pair of scissors to chop the underside off of a water bottle. Insert the bottle into the Polyformer. The gadget slices the bottle into strips. An extruder heats the strips and pushes out the plastic filament. From used bottle to ready-to-use filament, it is an thought with potential.


Picture: Reiten Cheng

Whereas filament does are available bigger and smaller quantities, most filament is offered on 1 kilogram spools. Once I spoke to Cheng on his Polyformer Discord channelhe instructed me that roughly 33 bottles would create a kilogram spool of filament.


Picture: Reiten Cheng

I see this as an amazing group or makerspace mission. A faculty or makerspace might gather the bottles and switch them into filament spools.


3D printed components and extra parts that make up the Polyformer

Picture: Reiten Cheng

As I discussed above, PET is a little bit of a problem to 3D print, particularly with how stringy it will get and the way troublesome it’s to dial within the temperature settings. However as soon as that is found out, a faculty or makerspace might have a nearly infinite (and free) provide of this very sturdy 3D printing materials.


I used to be notably interested by how the bottles are reduce. Discord person @Alextrical instructed me that, “It is the bearings that reduce the bottle, the perimeters slide over one another and shear the plastic just like scissors.” So this could be protected in a group setting, and there aren’t any points concerned in sharpening or changing blades.

It needs to be famous that Cheng is not the primary to construct a PET plastic bottle to filament recycling gadget. He cites as inspiration Joshua Taylor at, which has plans and components lists for the same gadget. Taylor’s strategy is to transform a Creality Ender 3 3D printer right into a “Plastic Bottle Pultrusion Unit”.

It is an fascinating strategy – upcycling a 3D printer to make a tool that recycles plastic bottles for use as a filament for a 3D printer.

So what about you? Do you suppose you may construct a tool like this? Do you need to do your half in recycling plastic bottles by turning them into 3D printing filament? Tell us within the feedback under.

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