3D Printers can produce quite a lot of waste,
especially if you’re mutli-color printing. Particularly the very popular Bambulab printers
purge out a ton of little filament poops every time you switch from one color to another
and this adds up! I recently printed a multi-color version of
Zelda’s Majoras Mask, and this print not only took six whole days, but it also purged
1.2 kg of material for a 500 g print, which is kind of insane! The good thing is I have a filament extruder! So can we recycle filament poop into new,
usable filament? Let’s find out more! Guten Tag everybody, I’m Stefan and welcome
to CNC Kitchen. This video is sponsored by VoxelPLA, which
I exclusively used to print this beautiful model. On such long and big prints, you need a reliable
and also affordable filament and this is what VoxelPLA provides. Their Pro PLA, which comes in 12 different
colors sells for only $16.99 a spool and ships free within the US if you purchase 3 spools
or more, with bulk discounts available for larger purchases. Voxel recently expanded into selling high-quality
printer accessories with their enclosure kit for the Bambulab P1P and what I like most,
the Voxel Bento Box designed by Thurtheframe. The Bento Box is a two-stage HEPA and activated
carbon filter that fits all the Bambulab X and P series 3D printers as well as the Voron
Trident. It comes mostly assembled, so you can easily
and quickly install it in your machine to reduce the emissions during printing. So, if you live in the US and want to stock
up on filament or want a hassle-free air filter for your printer, then go to VoxelPLA.com! I seriously have to admit, even though I do
own a ton of filament right here, it always pains me if I have to throw 3D prints away
or just waste filament. When printing regular parts, you can always
consider if this print is something you really need, or if it will land in the trash very
soon. Yet sometimes you don’t really have an option! The most popular multi-color printers at the
moment are Bambulabs X, P, and A series printers with their AMS unit. They use a so-called multiplexing system,
where you have one tool head into which you can feed multiple, in Bambulab's case, up
to 16 different filaments for multi-color and even multi-material printing. This system is simple, reasonably cheap, and
honestly one of the most reliable options on the market, but having a single nozzle
through which you feed all the different colors comes with a problem. When switching between colors, you need to
purge out a considerable amount of plastic before you get rid of the previous color. The Bambulab printers famously generate all
of these purging poops that the printer spits out of its back and which will considerably
pile up after a while. Instead of throwing them in the trash, I want
to use some of my collected filament poop and make new filament from it. I’m a bit lucky in this regard because 3DEVO
provided one of their filament extruders and shredders a while back which I can use for
this task. This equipment might not be in the price range
for home users, but it’s great to do a proof of concept! And if you are interested in seeing if this
is also possible with more affordable equipment, make sure to be subscribed, because I bought
the German-made Artme3D DIY filament extruder that I’ll be assembling and testing very
soon! The filament poops themselves are too big
to fit directly into the filament extruder, so I had to shred them first. This machine shears the plastic into small
pieces that then collect in a tray at the bottom. Once I had a bunch of material chopped up,
I quickly put it through a sieve in order to make sure that no big pieces were still
in the ground-up material. As I already said in the beginning, this is
not my first recycling project, but last time I had to learn the hard way that cleanliness
is of utmost importance. Anything that’s in the shredded-up material
will later land in our filament. The multi-color print poop right here all
used to be PLA filament which has a rather low melting point. So when collecting the material, I really
tried to make sure to not have any purge material from polycarbonate prints in my pile because
these might render my material useless. Another problem is foreign debris. Last time I had several clogged nozzles because
metal particles somehow got into my recycled filament. To get at least magnetic particles out, I
tossed a strong neodymium magnet into the box with all the shredded material and moved
everything around for a while, which should make steel particles adhere to the magnet,
which I can later remove and then clean. But now to extrusion. I have a 3DEVO Composer at my disposal, which
is a very compact lab filament extruder. It’s by far not cheap and certainly not
the best option if you wanted to make filament at a larger scale, but it gives me the option
to play around with material extrusion without the need for a whole extrusion line. So I turned it on and waited until it was
heated up. Then I started flushing out all the old material
that was still in the extruder barrel. At some point I added the transparent hopper
and inserted this vibration spider. So normal plastic pellets are round and flow
without a problem in the hopper by themselves. Our regrinds, on the other hand, are all very
sharp and tend to interlock, consequently blocking the flow to the extruder screw. The vibrations help the particles flow and
should result in a better extrusion result. The extruder itself is basically a big auger
in a heated barrel that will slowly move the material from the feed zone all the way to
the nozzle. On its way it slowly melts, the air bubbles
are pressed out, and it’s also getting thoroughly mixed. So, unfortunately, we probably can’t expect
a rainbow-colored filament coming out of the extruder but rather a mix of all the colors
we shredded. And what do you get when you mix all of these
colors together? Yes, exactly, poop brown, which is kind of
on theme if we remember that this used to be printer poop. I let another couple of meters of the new
material extrude out so everything had a bit of time to settle and then started the spooling
process. So, working with shredded prints and print
waste is always challenging, and I once again noticed that when just taking a look at how
the diameter of my extruded filament varied. Such a professional extruder has a closed-loop
control system for filament diameter. The molten material comes through a nozzle
that’s fairly larger than the 1.75 mm intended filament diameter. The right dimension is achieved by stretching
the soft string, and the more you stretch it, the thinner it gets. So, a diameter sensor measures the thickness,
and an adjustable puller wheel stretches the filament. In theory, this should make sure that we can
stay within around +-0.05mm of the filament diameter we want. Unfortunately, if the flow through the extruder
is uneven, the system can’t compensate quickly enough, and we get either a too-thin, or too-thick
filament diameter. And this is what unfortunately happened on
my first batch, and we can’t can’t only see that on the graph but also when take a
look at the filament itself after I pulled it out of the machine. Printing it went okay for a bit until a thick
section jammed in the filament path and ruined the print. Even though the print itself looked okay until
that point, I was clearly able to see the sections of thicker and thinner filament on
the part. Okay, so that’s unsatisfying, but I had
an idea to fix that. Years ago, I built myself a filament pelletizer
that was still sitting in my basement. This machine chops down filament into small
pellets by feeding it into a drill-powered auger. I didn’t have the old electronics anymore
to power the stepper motor, so I simply connected it to my old Ender-3, which’s running a
DUET board and has the Mutant Tool Plate system installed. The idea here was that the more regular shape
of the chopped filament could be more consistently fed in the extruder, resulting in a better
filament. It’s an additional step but also used in
industry, and if it improves quality, it might be worthwhile. So I started the extruder for a second time,
and after purging out the remains of the last extrusion, I started feeding our DIY filament
pellets. At first, the results looked significantly
more consistent, and there weren’t a lot of outliers. The roll of filament looked okay and still
had the brown color from before. Also, the initial print results looked significantly
better with less banding. Unfortunately, when I later came back to the
print, I again only had part of an owl, and I got filament jammed in the extruder. Upon further inspection by just running the
filament through a bit of Bowden tube, I realized that I again had blobs on the filament, which
were way larger in diameter than the 1.75mm that the material should have. Yet I couldn’t give up! I wanted to succeed in converting multi-color
purging poop into usable filament. At that point, I remembered that I had similar
problems during extrusion in the past when the material just wasn’t dry enough. Most of the purging poops I used for my first
batch were from my PLA waste box that were able to absorb moisture for months. So, for the second batch, I mostly used waste
from very recent prints. To dry the material even further I played
around with vacuum drying, where the vacuum is an additional force to pull out any moisture
from the material. I tried pure vacuum drying in the past and
had only medium success, so this time, I stepped it up two notches. Not only did I add two big bags of desiccant
to the container, but I also put the evacuated pot onto the bed of my QIDI X-Max 3, which
was heated to 60°C and regularly attached the chamber to the vacuum pump for 15 minutes. After a day, I shredded the material, put
it again into the vacuum chamber for a night, and then started extrusion. The first interesting thing was that the color
I ended up with on the filament had rather a greenish trashbag color instead of the brown
from the first batch. That’s simply due to the different colored
materials that were mixed together. I first thought I’d also have to extrude
a rough filament, pelletize it, and then extrude it again. Yet this second batch extruded very nicely
with barely any variance out of the printable range. The melt itself also looked so much smoother
without any bumps, and after around 1.5h I had my second spool of filament made from
recycled purge poop in my hand, and oh boy, did it look well! At first sight, I wasn’t able to see any
problem, so I went ahead and started the first print. Of course, with this greenish color, I could
only print a Master Chief helmet. I had no hiccups at all and ended up with
a very nice and clean print. I could see tiny variances in extrusion rate,
but other than that, this seemed to be a well-usable material made from 100% 3D printing waste! Remarkable! After the first failed batch of material,
I wouldn’t have expected that the second one would turn out so well! It was another good lesson for me to work
cleanly and with dry material, yet also showed me what the challenges are in trying to make
recycled materials. Of course, if you consider the price of the
machine and the manual labor, this is not something that’s economical on a small scale
and even the environmental aspect is debatable, looking at all of the mess and microplastic
that I made. Yet I still think it was another great proof
of concept to show that 100% recycled 3D printing filaments are possible. Not everyone can and should afford such a
price lab filament extruder. Still, there are alternatives like the Artme3D
or even my old Filastruder on the market that could make sense for maker spaces even if
it’s only the challenge of getting a process like this working and not only looking at
the money aspect. Fortunately, there are more 3D printing recycling
companies popping up worldwide. We have the RecyclingFabrik in Germany, but
there is also, for example Printerior in the US, that accept scrap prints for recycling
into filament. And you can’t only recycle 3D printing waste
into new filament, there are numerous examples where people use it for injection molding
or seriously just melt it into sheets to then machine on a CNC. If you’re interested in anything like that,
then definitely also check out Precious Plastics and make sure that you separate your print
waste into the different types of polymers right from the start! And I’d love to hear your thoughts on recycling
3D printing waste. What are you doing with your failed prints,
and would you buy recycled material even if it sometimes wasn’t as perfect as filament
made from virgin material? Leave a comment down below!
