Can you print (with) your spools?

Let’s find out what materials we can and can’t shred into 3D printer filament!

Product links are affiliate links - I may earn a commission on qualifying purchases (at no extra cost to you)

[DandTeePrinting]

Great Video. Alot of people think it's so easy to just recycle your filaments. Thanks for fully explaining how hard it really is.

[SianaGearz]

I recently read a paper "Mechanical properties of ternary blends of ABS, HIPS and PETG". It's from research in South Africa where there is a substantial purge volume from sheet extrusion when they change material, and they really would like to use the intermediate materials somehow and not let them go to waste.

What i learned is that ABS and PETG are compatible with each other and produce a cohesive plastic. But how does it print? It could have really interesting properties, don't you think? And also that adding any amount of HIPS destroys cohesion. Which is funny since HIPS is not a copolymer but a blend itself. One should be really careful with what garbage polymer ends up in the mix, for example any amount of PP would be very much not OK.

The other thing i learned is that one can use SBS (Styroflex 2g66) as a universal cohesion agent which may make bad polymers and dumb mixtures workable.

[mechanoid]

Years ago, when I worked at a plastics molding company, they would recycle 'waste' plastics. Sprues, purges etc. They would never use it without adding virgin pellets to the mix. In fact I think it was less than 10% of recycle to virgin material. This was blended in the mixing department. As you found out, keeping the different types of plastic apart was key!

[imrefazekas]

You should try out regular household plastic waste. PET printing (from bottles) has been explored before, but it could be further refined and there are other kinds of plastics out there as well.

[astrumrocket]

Couple years back, I had the delight to work with 3devo products, the shredder and what was then their top of the line extruder. The shredder kept jamming, and when asked about it, their support had no idea how it actually worked, and (I am NOT kidding about this), they took pictures of themselves shoving plastic bits into it with thick wooden boards, and suggested we try the same. Their extruder promised something like 0, 5/1kg of filament an hour, but it barely managed to do about 2-3kg a day, that is when it worked at all. An utterly miserable experience, and all those terrible memories of endless lost time came to me when Thomas mentioned 3devo. ...now to watch the rest of the video! :D

[paladingeorge]

I love the lizard doggo in the background! I have been so hooked on Satisfactory that I didn't even bat an eye when I noticed it but then towards the end of the video it hit me - Thomas loves Satisfactory too!

[sparrowthenerd]

I worked a bit with injection molding during the summer, and yeah... we had 3 different purging compounds to satisfy the temperature ranges of all the different plastics we ran (prototyping machine). It sure is important!

[TheSndmn]

It's kinda cute how excited you were about the mechanically coded safety switches. I work with them so much, I never gave them a second thought.

[HitoPrl]

17K €, certainly not for the hobbyist.

[johnmccardle]

What I want to use recycled filament for, on the Prusa XL: use recycled material with a 0.8/1.0/1.2mm nozzle, and make the inside of every model and all infill out of any color. Tool change for the outer layers to be new material through 0.4mm nozzles. How much print time and filament would it save? Can it get close to regular surface quality? Can you ignore more contaminants with huge nozzles?

[WreckDiver]

In commercial recycling they will mix like materials together, but the systems are quite a bit different. The sprue size is WAY bigger than our tiny hot ends. This allows for inconsistencies. Place by me makes plastic pallets and plastic barrel carriers out of recycled resins. The machine is sloppy as all get out, not precision at all. The feed sprue is at least 10mm in diamater...yea, they are huge.

You are 100% that when you see "recycled content" it is generally scraps from their own manufacturing. Funny thing there? SO many places where I live have been doing this for a LONG time, but now they are putting in their specifications...AND CHARGING for it. Genius on them, but when I used to negotiate with these shoot and ship houses they were all "Oh this is so complex". I was always "So, please, take me through it, 2 years ago, before your "Recycled Content" resins you had a grinder, drier and dust separator on all your injection mold presses. You took the sprue(s) and runners and put them into the shredder, it then went to the dryer, then to the dust separator. There it was metered into the resin. What changed". Of course...NOTHING. Except they charged MORE because "it requires more process". Yea...and so many people ate that up as fact. :(

[FilamentStories]

Tom, this was fascinating. Recycling 3D printing waste (and their spools!) is a much more challenging task than most people think and your experience shows how complex getting quality, useable filament can be. It was interesting seeing the whole process with the 3devo products. Also, I just love how you had a handy engine hoist to lift the grinder!

[proaudiorestore]

Thomas, it's great to see that even a veteran like you is still learning the hard way! I remember watching you build a Printrbot about 10 years ago, which inspired me to buy my own and get into 3D printing. The printer had its technical challenges, much like what you're facing now. Do you think in another 10 years we'll have a disruptive brand similar to Bambu Lab making 3D recycling as simple as tossing in plastic and getting filament out? We're not there yet, but who would’ve thought 3D printing would be this easy today? Just an interesting thought. Keep doing what you do!

[chuckthetekkie]

You don't have to make filament with the shredded material. Teaching Tech used shredded prints to make sheets of abstract colored plastic that can be used in DIY craft projects. I would imagine you would have less issues with slightly contaminated shreds. In my opinion, that's probably a much better use for empty spools and leftover/failed prints.

[shibbleswentworth]

Way back in the day we bought protocycler serial number 8 from Kickstarter and actually made about 20kg of petg abs and asa with it. Dry time is about 80C for 4 hours and no food dehydrator is gonna do that better a convection oven. You found out the hard way that is the second biggest factor behind mixed plastic types. Petg is almost infinitely recyclable where abs gets brittle a few cycles in due to butadiene and chain breaks.

[iamjeffreydohnt]

...chuck the contaminated blue filament into a small vat of acetone? It will 'eat' the ABS and leave the PLA alone - rinse and voila! - Thanks for sharing this kit... VERY handy for me.

[Lampe]

This reminds me a lot of CNCKitchen's video about the recycling of old 3D-printed parts using a self-built reextrusion line.

[TheLaXandro]

Toss up some 80-20 mix of PETG+PLA, to create a weak support filament that prints but then easily crumbles away when it's done with its job.

[uuhamm]

A trick I learned working in a recycling plant was that if you aren't sure what kind of plastic something is, you can burn a little piece of it and smell it. The different smells of different plastics is unmistakable. Now that is probably a lot worse for you than scratching it and smelling it. But also much more fun.

[Tynted]

Wow, I am blown away by how much the small amount of contamination affected your prints! I would love to see more videos just exploring shredding/recycling different plastics or waste 3D prints in more detail. Some ideas that come to mind:

- Do a bunch of testing and find a good "recipe" for recycling PLA or PETG or ASA waste prints, to show the difficulty level of recycling your 3D prints. Is it possible to do it without using any virgin material at all?
- Try making a batch of filament from virgin pellets. Then, print it all and recycle it. Repeat this process and see how the plastic is affected by each cycle of recycling. How many cycles are possible for PLA, for example?
- What is the percentage of ABS required to ruin a batch of recycled PLA parts? Or percentage of PLA required to ruin PETG or ASA parts?
- Try to get your shredded product into a finer size - how does that affect your results? Is it difficult? Does it make the resulting 3D prints much better? How viable is it for people to do?
- Can a sander or Dremel remove the stickers on spools more effectively so you don't need to use solvents to clean the plastic?
- Go more into detail about how mixing plastics from different manufacturers such as PLA or PETG affects the resulting batch of filament? Is it a big effect? Can it ruin a batch of plastic?
- Does printing with a larger diameter nozzle make recycled filament more viable? Since contaminants will have a higher chance of being able to pass through it.
- There maybe chemical tests you can do on spools or samples of plastic you want to recycle to gauge their grade or quality. Can any plastics be judged in this way to see if they're good enough for recycling?

Thanks for a great video! I love how you're always trying to branch out on your ideas