Conventional Plastic Is About to Disappear

Key takeaways

3D printers can use filament made from recycled PET bottles, giving plastic waste a second life.
Bio-PLA, made from plant sugars, is biodegradable and renewable with a low carbon footprint.
Used filament can also be recycled in a closed loop, keeping material out of landfills.

In recent years, 3D printing has established itself as a new and much easier way to work with plastic. What most people don’t realize, though, is that 3D printing uses a special polymer that also comes in a bio version which is practically harmless – and printers can even print with polymer made from recycled plastic bottles.

From plastic bottles to filament

Recycling plastic bottles into filament – the material used for 3D printing – is a fascinating and genuinely useful process. To turn bottles into filament, you go through several steps:

Collect and sort the bottles by type and color. Only PET bottles (polyethylene terephthalate) should be used – the ones marked with a triangle and the number 1.
Clean the bottles of labels, dirt, and any leftover contents. Water, soap, and a brush do the job.
Cut the bottles into small pieces or strips, using scissors, a cutter, or a dedicated machine.
Dry the plastic pieces in an oven or in the sun to remove moisture, which can affect the quality of the filament.
Melt the pieces in a special extruder that turns them into a hot, flowing mixture.
Draw the mixture through a nozzle that forms a long, thin filament – usually 1.75 mm or 2.85 mm in diameter, depending on the printer.
Cool the filament in a water bath or air stream to lock in its shape and stiffness.
Wind the filament onto a roll or spool for easy storage and transport.

How bio-based PLA is made

Bio PLA is a bioplastic produced from plant sugars such as corn syrup, cassava, sugarcane, or sugar beet. The sugars are fermented into lactic acid, which is then polymerized into pellets. Those pellets are melted and shaped into all kinds of products – 3D printing filament, cups, boxes, cutlery, and more. Bio PLA is biodegradable, renewable, and has a low carbon footprint: it doesn’t pollute the environment, it’s safer around food and drink, and it works for a wide range of uses. The trade-offs are that it’s more expensive, less durable, and harder to recycle than ordinary plastic.

Recycling used filament

Once you’ve printed with filament, the leftover material can be recycled too. The process mirrors the one above: collect and sort the filament by type and color (use only one kind of plastic to avoid incompatibilities when melting), clean off dust, grease, and residue, cut it into small pieces, dry it, melt it in an extruder, draw it through a nozzle to the right diameter, cool it, and wind it back onto a spool. It’s a closed loop that keeps material out of the landfill.

Frequently asked questions

Can you make 3D printer filament from plastic bottles?

Yes. Clean PET bottles are sorted, cut, dried, melted in an extruder, and drawn into filament at a set diameter (usually 1.75 mm or 2.85 mm), then wound onto a spool.

What is bio-PLA made from?

Bio-PLA is a bioplastic made from plant sugars such as corn, cassava, sugarcane, or sugar beet, fermented into lactic acid and polymerized into pellets.

Is PLA biodegradable?

Bio-PLA is biodegradable and renewable with a low carbon footprint, though it is less durable and harder to recycle than ordinary plastic.