Which plastics can be recycled into filament for 3D printing?

Transforming plastic waste into new filament allows you to reduce waste. However, not all plastics are recyclable. Let’s see together how the most used plastics behave.


We all know the importance of recycling plastic materials, and how necessary this is to safeguard our planet. To get an idea of ​​how much plastic impacts on the environment, just consider that according to various studies every minute the equivalent of a truck full of plastic waste is dumped into the oceans (source: Greenpeace).

Everyone can help turning the tide on plastic. We as 3D printing enthusiasts are required to have special attention: every day we handle plastic materials, and in the printing process we inevitably produce a certain amount of waste.

We designed our domestic extrusion system to go in this direction and help mitigating this issue: in fact, it allows to transform the waste materials of 3D printing into new filament, in order to bring them back into the production line and reduce waste. This way you use less plastic and save on the purchase of new filament.

However, not all plastics are recyclable at home, and not all behave in the same way: for this reason it is essential to correctly identify the plastic material you are working with. Doing this is quite simple: for most plastics all you need to do is check the distinctive number in the typical “recycle” icon. At this point, you can immediately understand whether the material can be turned into filament or not.

Plastic materials

Here are the main plastic materials:

PETE or PET (1)

This is probably the most common material, frequently used for bottles, flacons and much more; it is very difficult to transform it into a new filament. Sometimes it can absorb the smell of food and liquids for which it is used as a container and above all it is designed for blow molding. For this reason extruding it is complex.

HDPE (2)

This material is used in the production of plastic bottles, food containers, corrosion resistant pipes. You can get new filament by recycling it, although it is recommended to have a cooling system to ease the process (like the one made available by our Spooler).

PVC (3)

Used for food packaging, construction and medical equipment. Due to its potentially dangerous chemical composition, PVC is not recyclable at home.

LDPE (4)

LDPE is widely used for the manufacture of various containers, disposable bottles, bottles for detergents, pipes, plastic bags. It is a potentially recyclable material, although chopping it is not easy due to the shape of the elements in which we find it, which are not always easy to treat. For this reason we recommend not to extrude this material due to the difficulties it presents.

PP (5)

Polypropylene is one of the most used plastic materials, and can easily be turned into new filament.

PS (6)

Commonly known as polystyrene, it is used to make food trays, cutlery, plates, caps, packaging and more. It can be recycled into filament without too much effort (in any case it is possible that particular types of polystyrene cannot be extruded).

Other plastic materials (7)

This group includes numerous plastics; for more information on extrusion, we recommend that you visit the dedicated page on our website.

Finally, a small clarification: although extrusion is possible for the materials we have indicated, each plastic, even of the same type, can show a different behavior (due to the injection molding of the original parts). Furthermore, the quality of the extrusion can depend on various factors, such as the external temperature or the size of the starting granules.

For more information on extrusion of the most common materials, please download for free the guide below. We remain available for further information or for specific assistance requests.

Download Felfil Materials Guide