3D printing is extremely useful and has revolutionized some aspects of what can be made in small workshop and home environments. But plastics are a huge problem, and it sucks to be contributing to that. In this note, I'll examine some options for eco-friendly 3D printing filaments, to explore how we can limit the environmental impact of 3D printing.
To judge the eco-friendliness of a filament, I've come up with the following criteria:
- Is it made from renewable resources? I guess turning fossil fuels into durable products is better than blasting them into the air, but it's still not a sustainable practice. Especially if a plastic part lands in the garbage and ends up being incinerated.
- How well can it be recycled? As far as I understand, all thermoplastics can be recycled, but their physical properties might degrade by some degree when doing so.
- Is it biodegradable? If the material can no longer be recycled, or maybe is lost and ends up on the ground somewhere, it's great if it can just rot away and not end up as permanent trash.
The following list is a snapshot of the current state of my research and experiences. If you think that it is incomplete, or if I got something wrong, please let me know! I intend to update this note as I learn more.
PLA is the most-used filament in 3D printing, mostly because it's cheap and easy to print. According to Wikipedia, it's typically made from fermented plant starch, and it is possible to recycle it without loss of properties, both of which are great. It can also be incinerated without too much trouble, as it's only made up of carbon, oxygen, and hydrogen, none of which are toxic.
The problematic aspect is its biodegradability. It will degrade under specific conditions, but outside of an industrial composter, it will degrade very slowly, and is basically just as harmful as any other plastic.
So in conclusion, everything's great, if you can dispose of your parts in a controlled manner. Otherwise, not so good.
NonOilen by Fillamentum is very promising. It is made from renewable resources, recyclable with little loss of properties, and degrades more quickly and easily than PLA. According to the manufacturer, its improved biodegradability means that it can be disposed of as biowaste.
I'm not so sure of this myself, as I assume that this must depend on how biowaste is processed in a given locale. However, I'm not an expert, so it's completely possible my doubts are unfounded. This page about NonOilen waste implies that it is also possible to compost NonOilen at home. I haven't tried this (don't have a compost, unfortunately), so I can't speak to that.
Other than that, NonOilen supposedly prints similarly well as PLA, while having better physical properties. What stands out to me is its temperature resistance of 110°C, which is much higher than PLA, and means it can even be boiled in water. As of this writing, I've printed a few small test parts and found NonOilen easy to work with. I'm looking forward to using it more in the future.
GreenTec by Extrudr is a whole line of biodegradable filaments with varying properties. There's GreenTec Flax, which seems roughly comparable to PLA. GreenTec Wood and Pearl, which seem somewhat weaker. GreenTec (without qualifier) seems comparable to PLA in its properties, although with a much higher temperature resistance of 115°C. GreenTec Pro and GreenTec Pro Carbon are stronger than GreenTec, and Pro Carbon is even UV-resistant.
This short summary necessarily leaves out a lot of detail, of course, so please study the data sheets of each material, if you're interested in using them.
According to Extrudr, all of the GreenTec materials are biodegradable according to DIN EN ISO 14855. I don't know what that means, and of course that standard doesn't seem to be freely available. It is different from their PLAs though, which refer to a different standard (EN 13432).
Given that Extrudr's PLAs and the GreenTec line refer to different standard in regards to their biodegradability, there's hope that GreenTec degrades more easily. This requires further research though. At this point, I'm not aware of any information about how biodegradable these materials really are. Another disadvantage is their price, which is much higher than PLA (but similar to NonOilen).
This turned out to be a very fruitful topic, and I was able to find much more information than I could analyze and write up in the time I had available. If you found the information here useful and would like to know more, please let me know! If there's enough interest, I will try to expand this note.
Until then, here is a list of links to more interesting filaments I found: