Healthy 3D-printing

In the 3D-print world there is a strange mix of fear of, and reckless fatalism in connection with, microplastics.

Microplastics is plastic dust particles (1 μm - 5 mm). They have spread through the environment and is now inside plants and animals. Including humans. The smallest particles (1 μm - 100 μm) can be found in the blood, and can thus settle everywhere in the body. It is not known for sure what consequences that will have, but the prevailing view is they will not be good. If nothing else, it is a development it will take a long time to reverse. So we are going to live with the effect for a long time, whatever it turns out to be.

Microplastics is not only created when you 3D-print, but in all kinds of ordinary situations: when clothes with synthetic fibers is worn, when tires are worn, when plastic packaging is opened, when kitchen utensils made of plastic is used, when PU finished objects are worn, when fluid is contained in plastic bottles...

They are things we all do all the time, again and again. It is completely unrealistic to stop it. The difference that you and I can do, is only like two drops of water in the ocean. But does that mean we should give up doing anything about it, or should we do what we can? And if we do what we can, will we even be able to have 3D-print as a hobby?

That was a lot of questions, but let us start by seeing which possibilities there are for reducing microplastics impact when 3D-printing.

Recommendations

For those with short attentions spans, that wont read the rest of the article anyways, here are my recommendations:

1. Use biodegradable filament.
2. Use food-grade filament.
3. Avoid sanding, filing and sawing when you postprocess.
4. Collect all plastic scraps and avoid spreading.

1: Biodegradable

As every 3D-print-nerd knows, there are large differences between different types of plastic. So it is no surprise that some types are almost undegradable, while others are more easily degraded.

Imagine small dust particles of the type of plastic that is almost undegradable. The body is very poor at removing them mechanically, and because it cannot degrade them, it will take generations to get rid of them.

PLA is unique in being the only common type of filament that is biodegradable. That includes mixed filaments, like socalled "wood" filaments, that are a mix of PLA and wood fibers. Because both are biodegradable, those mix filaments are also biodegradable.

PLA filaments and PLA mixed with biodegradable materials, are the healthiest to print with.

There are also some filaments of exotic plastic types, that has been developed to be biodegradable. But they are usually somewhat more expensive. They appear to be meant for applications where strict regulations apply. Dont use them unless you have to.

2: Food-safe

But PLA is not usable for all models unfortunately. Some has to be fireproof. Some has to be under constant load, like a compressed spring. Some has to endure strong UV light for long periods of time. All examples where you have to use some other type of plastic.

Even if you printed with biodegradable filaments exclusively, things would not be that simple. Microplastics would still be created, and the time it would take to degrade it would have the impact that any other microplastics have.

But there is a diffenrence in how harmful different filaments are. The plastic that is least harmful is the kind we already eat or drink a little of every day. That is, plastic that have been approved to have contact with food.

If you look carefully, you will see that some of the ordinary filaments you can buy, are food-grade. The microplastics they create, is less harmful in the body.

Food-grade filaments are healthier to print with.

Even if you for some reason dont care about microplastics, it is a good idea to use food-grade filaments for everything that you print. Including models that are never going to touch food. Your models could end up in the mouths of small children or pets, even when that is in no way intended.

Finding food-grade filaments is not easy. They are not as common as they ought to be. Here is a list with the ones I know about:

For food-grade filaments there are also some made of exotic, quite expensive, plastic types. They are not meant for you and me, but seem to be intended for specific applications where some specific requirements apply.

3: Postprocessing

Postprocessing is one of the most effective ways to create microplastics. That is, by sanding, filing or sawing your models.

Avoid sanding, filing and sawing plastics.

You can reduce the amount of microplastics if you add a filler before sanding. That of course only helps if you use a filler that does not contain plastics.

A better way to reduce microplastics, is to smooth out the surface with a solvent.

The very best way to reduce microplastics, is if you can design your models so they minimize, or even eliminate, the need for postprocessing. Most obvious way is to avoid supports, and to print multi-filament models in multiple parts that you assemble afterwards. Such designs are not always possible, but think it over. The more experience you get, the better you will see the possibilities.

4: Avoid spreading

You can limit the spread of microplastics in the environment by observing a good hygiene when handling it.

You can designate a few places, as the only ones where you create plastic scraps. There you should be quick to sweep the plastic scraps up before they pile up and start to spread. It is a good idea to have a dedicated plastic bag for them. Microplastics does not spread into the environment as long as it is inside the bag.

Collect all plastic scraps in a dedicated plastic bag.

If waste management in your local area handles plastics waste in a sensible way, it decimates the microplastics impact when they get it in plastic bags.

A few 3D-enthusiasts are experimenting with melting plastic scraps together and cast models with them. That is another way to reduce microplastics. Maybe the technique can improve over time, so the 3D-print hobby can fuse together with the "3D-cast" hobby. That would be a very elegant way to handle the microplastics problem.

To 3D-print or not to 3D-print, that is the question

It is quite a mouthfull to save the whole World. Just the thought can make most people give up before they get started. But it is the wrong way to think about it. Because even if it sounds hopeless, it is not that bad. The thing is, that what we do impacts our local environment the most. In particular the local environment that is our home. And we of course should limit the microplastics impact in our homes. If we as a bonus save the World a tiny bit while doing it, then that is great.

As a 3D-print-nerd you have an advantage, in that you know more about plastics than most people. Furthermore you can often print thingamajigs yourself, and thus be confident that they are made out of the healthiest possible plastic type. Add to that, that packaging is avoided, and by that the microplastics it would have created. As a 3D-print-nerd you make your own microplastics-bed and lie in it, so to speak. That is why the combination of 3D-print hobby and microplastics responsibility, makes a lot of sense.

If you 3D-print in a responsible way, my guess is that your microplastics footprint is smaller than if you didnt 3D-print at all.

But how realistic is all this for the printing you do? That depends a lot on the models you print. Maybe it is only possible to follow some of the recommendations. Maybe, when giving it some thought, it is possible to follow them all. Whatever you end up doing. it is of course entirely up to you. I am able to follow the recommendations myself for practically all my models, and I think most people would be able to.