♻ Mechanical recycling is very challenging. It takes a lot of time and expensive equipment to produce a material that would cost a fraction if just purchased new. Let me know in the comments what societal and technological innovations are needed to make recycling of failed prints and waste plastics more economical.

If one can't afford a reclaimer, a Chocolate Lab would be a great alternative. A Lab can chew up anything.

This is hands down the most thorough and clearly explained video on why recycling 3D printed waste is time consuming, challenging and expensive both in energy costs and products required to produce a useable resultant filament. The added degradation of the plastics from multiple heat cycles and the need for virgin resin to make a product that prints reasonably well is another factor that many people don’t often consider. Thank you for covering so well all the considerations and steps required to produce an at home, Makerspace or other consumer-based recycled 3D printer filament. It is a wonderful thing that so many people are passionate about wanting to recycle their 3D printing waste. It's just much more difficult to do than most people realize. Someday hopefully there will be a more straightforward path or more companies like Recycling Fabrik in Germany, who accept and recycle 3D printer scraps. I’ll be sending people your way to watch this video.when get questions in the future. Many thanks!

This was a great video. Looking at my own PLA waste I can say that supports are about 80% of it is and this makes me think that a perfect use for 100% recycled PLA with 0% virgin pellets added would be for a dual filament 3D printer where the recycled PLA is only used for support material. The physical properties really become irrelevant for supports and colour consistency wouldn't matter either.

Thanks for the shoutout Dr! We were very happy to help you out with our SHREDII 😃 Looking forward to more future collaborations 😁

Looks like the grinder would be less labour intensive if they changed the design so you had a big hopper at the top, it could grind on the large grinder and drop straight through to the next grinder, with a sieve built in below that (probably angled toward a collection bin) that could deal with the dust and then slide the correctly sized pellets out to the side, that would remove a lot of babysitting from the process. I've always fancied making something like this (on my list of 3000 other projects i'll never get around to it) but seeing this in action definitely gives me some ideas.

Even though the costs are still extreme, the advancement in small scale extruding is amazing. I can see this being a long term cost savings for a universities and maker spaces.

I worked in a recycling plant for PET and HDPE and it was interesting to see that you have faced some of the difficulties in small scale which the big recycling process brings with it.

The inconsistent feed of your virgin/regrind material can be improved with a screw that has a mixing section. Also, separate barrel heating zones can help control Feed, Mixing and Extrusion.

why not use a modified injection molding machine ( basically only the heating chamber and the piston, with a disk that has many 3mm holes ) , to get fairly uniform 3mm "spaghetti" and pelletize that ? instead of 2x grinding + extrusion to 3mm ?

What an extensive process, learned a lot! Thanks

If anyone wanted to make one of these there is a company in the USA called Surplus center. 1hp AC motors about $150, the gear box is about $130, the bearing pillow blocks about $15 each. Then all you need is a CNC or manual mill cut tool steel grinders. I've seen a guy make the grinders using plate steel with a central shaft that bolts the plates together. This can then be cut on a bandsaw or plasma/waterjet. some sheet metal case. One hell of a lot better than $15000. The entire units are very manual therefor easy to replicate. For the every day person wanting to be as economical as possible when printing.. the entire system if near 18k is way out of range, the ethics of charging education facilities that price is also questionable.. . Good concept, good company idea, greedy implementation and therefor bad environmental impact.. im the bin my left over prints go :( I should note the parts I believe are the same. Ironhorse is a chineese company on alibaba

You're a exceptional educator! You pack in so much detail but it all comes across and the explanations are so clearly worded and presented. I'll come back to this video as a reference for anything processing related in future. Thank you

So cool! Recycling prints has come a long ways since the idea was first floating around!

i think this marks the biggest game changing need in the industry today - once this can be done on a home basis it will be huge

I work at a filament company. This video is spot-on. I get asked daily by people if they can send me scraps to turn into filament, and the answer isn’t very quick or easy to explain, but you absolutely nailed it in this video. Our biggest sales are the lowest-cost filament. We’ve even made recycled PETG filament, but cost always has a bigger influence than sustainability when it comes to sales. You’re the first person I’ve seen that accurately explains why it’s not as simple as “adding old prints into a melter and making filament” and you even went as far to explain why it typically needs to be extruded TWICE. In the business world, labor = $$$, which makes recycling very difficult to make when competing with virgin resin pellets. I’ll be sending everyone who asks me about recycling over to this video. Thanks for taking the time to do this!

Excellent video - you explained so many things that I was struggling with in my adventures with plastic recycling.

Very well done as always. The thought organization in the video is outstanding.

could you try melting the shreded prints first into a solid sheet then shred that to create solid pellets/chunks

Thank you for this video! You have summarized my own experience in this topic and answered all my open questions on why i have inconsistent filament diameter on my diy extruder why filament is not the same as a new one, why do we need compression screws and the most valuable is how to fix all of that issues! Regranulating of the waste and mixing it with a new granules will fix all my problems!

Another banger from the Doctor, love it! was very interesting to see this "at home" setup explained in great detail, today i learned a lot! Would be cool with a follow-up video where you take us through a bigger facility to point out the differences and any other solutions they had to develop

Thank you so much for your efforts and helping to educate us all with your findings. This is hands down one of my favorite pages along side AVE and proper printing

This is possibly the best/most informative video on filament recycling. This is great, a complete honest 10/10.

I'm SO thankful you showed this in such detail. I have been very interested in recycling of 3d prints and I'm glad to know that this is not the direction to go in for now. It's simply too low of a return for too high of a cost. I look forward to the day that we have a 3d print recycling service in the Americas.

This video is exacly what I have been searching for months. Inceadible and thorough explanations!

Your channel is awesome. You explain the process very well.

Wow. Most effort on a UKposts video ever. It shows. Great work.

Exceptional video and a masterclass in thorough, yet concise scientific education. Thank you for the time and effort in putting this together.

Thank you very much for such a sober, educational, and comprehensive overview!

Very cool, I've wanted to venture into this myself, but I don't think I have enough print waste to make it worth it yet. Its odd they didn't just put a feed directly on the pelletizer to get a perfect cut length for different rpms.

I get so excited when u post !!!

Thank you for the effort, this was extremely informative.

This was super interesting and informative. Great video. I have kept my scraps for years for future recycling. Not sure what to do with it yet though

Thank you for this video, great content

Going down memory lane a bit. When bottles were glass, and some modern plastic containers, had deposits on them. Returned to a store, if your state participated, you got cash or credit. It was better than shattered glass on the roads and such. Shipping would be hell, but recycling drops in brick and mortar filament vendors could do the trick... a little. 6 kilos of old prints for 1.5 kilo spools. Dunno. Some big box stores do it with batteries. No money, but a central drop off.

I used to work at a plastic factory we had a water bath directly infont of the extruder to help with keeping uniform size

Yeah, *THATS PRACTICABLE*

It looks like a huge pain in the butt, but extremely educational and interesting. The biggest value is education and (although a pain) it looks very interesting to do... Almost even fun 😊

AMAZING VIDEO, very educative

Have you tried compacting the PET bottles and then heating them to melt in a bit more thick/solid object before shredding it? It should give more thick pallets with better flowability and thus be easier for the extruder to operate. I might be wrong but it's worth a shot.

Extremely viry nice idea and best filament making idea 💯👌

As an optician im very interesting to see if you can recycle cellulose Acetat frames. The goal would be to get uniform pellets to heat mold plates to cut out new frames. For the community could you test a cellulose Acetat spool because it is rare on that market. On the manufacture side i could read that it is possible to recycle PA so my question is while i saw that you have a printer from Formlabs, could you recycle prints with this and could make a PA spool out of it. Hope for more content like this special if you could try cellulose Acetat🙏🏻

thank you for the info on the bottle peeler recycle tech. I am interested in this but not at 20hrs per spool of sub par material

If your 3d print needs a specific center of gravity or ballast for a weighted base, I feel like pellets could be great to add mid-print as opposed to solid infill. Your QC on the pellets can be pretty loose and you still maintain plastic homogeneity should you intend to later recycle the same print. I'd like to see more investigations using heat (look at the PET droplets falling from the screw! 36:16 Could you get those small enough so they serve as pellets?) or maybe high frequency vibration cutting methods to simplify pellet creation and microplastic reduction? Thanks for sharing your experience and doing the economic calculation for us!

I was not interested in recycling prints, but after this video I am. Maybe not right now but I’m the future, your video was very informative and very high quality, this is the first video of yours I have seen but I am definitely subscribing and you deserve way more subs then you have man.

Thank you for the great explination 👏

Thanks for the video, this is very interesting stuff. The hollow filament produced by pultrusion is a non-issue -- you just increase the slicer's extrusion multiplier to compensate. I have printed many aesthetic and functional parts from pultruded PET bottles, including all the motion parts for a 3D printer. I agree that the process is quite slow and tedious, but the results are good. If you're dedicated enough, it is pretty much the only truly affordable way to produce filament at home.

The battle for recycling 3D printing waste continues. Have you looked into melting flakes into pucks? or using melting chamber with a piston to extrude into an inconsistent filament? I do understand the first proposition would degrade the filament further, but it might be worthwhile exploring.

excellent video, thank you !

A really informative Video 👍 For me it would be very interessting to see if the addition of a little bit of chain extender as masterbatch into the regrind/virgin would further enhance the mechanical properties. Do you have rheometry equipment to get a feeling for the degradation?

If you dry the pet flakes with a higher temperature it could pelletize. A pet-bottle in hot water shrinks a lot. So will the flakes.👍

I wish these machines weren't so prohibitably expensive, the setup is quite nice overall. I would love to see more recycling done on a small scale by individuals such as those of us in the maker community, but at $12000 for just two of the four machines you realistically need to make quality filament, the ROI isn't there except for larger businesses that have employee time to burn between other tasks. At $2,000-$3,000 all in for a setup such as this, I could see it becoming rather commonly used, as the ROI on that is more tangible for an avid maker or small makerspace to digest investing in.

Very informative. Thank you.

I worked in injection molding over 40 years and I worked with plenty of regrind materials. I kept looking for you to make a mistake but you hit everything on the head good job. Those are all the same issues all recyclers deal with . I worked at an injection molting factory once that advertised a product as recycled materials but used virgin because it was cheaper than recycled. Also there is a difference between pre consumer and post consumer plastic.

This is actually a very good investment if you are operating a big 3d print farm business. But only if you got the experience have source's of free plastics and the time.

One of the best recycling videos on UKposts. Thanks a lot. IMHO plastic is to valuable mostly non renewable resource to be town away

What an outstanding video! Do you think you could improve the extrusion of PET by grinding it to a powder instead of shredding it or will the same problem occur as with the PLA particles that are too small?

I mostly specialize in material development that can be more easily transferred into alternative production methods and am currently working on a solvent-based extrusion method for ABS (also easily adaptable to other plastic/polymers in the recycling sphere of interest that work with easily obtainable solvents). It's a real easy build that can be done in a weekend, as I just obtained all the remaining parts to mock up the extruder yesterday. If you're interested in yet another project, this will definitely cut down on redundant processing of oddly-shaped flake, but better yet, should be able to bypass the shredding phase altogether. I do have a high RPM alternative shredder that kicks out almost powderized stock, but have been loading simple compressed samples quite well in my testing phase. I'm currently focusing on recapturing the solvent for subsequent passes as that is the part I'd most like to reuse, as it contains quite a lot of liquefied microplastic stock. Not that it's terribly expensive, but being able to reuse the solvents makes it that much more affordable rather than letting them vape off to atmosphere, aside from environmental concerns with doing so.

Excellent content!

I would modifie the hopper and auger starting with large screw tapering down to the standard shaft.

Excellent video!

Hey, we have a local maker space. I totally agree with all of your conclusions. One thing I am still debating is converting 2.85/3mm filaments, which we have lots of, to 1.75mm filament, using some pultrusion instead of extrusion. we have anything from PLA to PETG, wood fill, bamboo fill, bronze fill, etc. I don't intent to even try TPU and similar flexible filaments. Is it doable? worth it? Thanks!

Very enlightening. Seeing all the scraps I throw in the bin I really wanted to put that waste to good use, probably on prototypes rather than final prints so plastic quality and colour isn't a big concern for me. The time, money and effort required to be doing the 'right thing' is very off putting when a new spool of filament is so reasonably priced. This has really got to be something for 3D printing clubs / shops or education facilities to offer a recycling service. Bring along your scraps (free donation) and purchase recycled filament spools at cheap prices. As long as it makes sense for them financially as well.

great video..One thought is ,if you melt the whole bottle to a smaller ,sphere shape,and then perform the shredding process..That way i think you might be able to get rid of the flake shape of pet bottle shreds to much more of a granular shape...

Instead of grinding regrinding and melting the bottles, then pelletizing them and reextrudimg them, could you melt them in an oven in a 3 inch by say 18 inch tray, until you have a bar that is half an inch thick, and then grind that? It might avoid some of the flake problem and let you process the bottles faster.

Great educational video…and it trashed my ambitions to recycle my PLA prints, bummer.😢…. BUT, I learned a lot, was really interesting!

Nice video, some things about pulltruders are not correct, and maybe you chose one older model. The other thing is that pulltruded filament can be used to print up to 0.08mm , I'm doing it with my printers, you just need to increase the flow.

@DrDFlo do you know a way to merge recycled PET with something that could transform it to PET-G? Maybe painting the bottle with some chemicals before shredding or pulltruding it?

When making PET bottles in a factory, they start with a preform that looks kind of like a short test tube with thick walls, and then use compressed air in a die in an oven to expand it to the final shape, like a balloon. Would it not be possible to do the same in reverse? Like using a vacuum pump connected to a metal bottle cap and then put it in an oven or perhaps using hot air? Then it should be thicker and easier to granulate.

Would there be any real issue with milling recyclables into a powder ( maybe the virgin pellets as well ) and using that as feed stock for extrusion?

well that explains my problem with extruding my grindings. They usually got stuck and no extrusion.

Great video! I’m sure you’ve already experimented with this, but have you considered heating the PET regrind slightly to cause it to shrink and take on a more irregular shape? This could potentially increase the friction between the regrind and the barrel.

For the PET bottles, wouldn't it be faster and easier to melt everything down and condense on a tray or some other container and then chop it up so it's not so thin of pieces? That would also help the moisture issue.

wow, really interesting. Thanks.

I wish they would make a law to make it easier to recycle plastics. Make all bottles one type of plastic, all containers over a liter a single plastic, etc.

Would it lower the chance of clogging if machine ran vertically in some way like some have adapted theirs to do

Really interesting video. I have to wonder what the energy use impact is per kg of material produced compared to a factory setup. I expect it will be less efficient, but is it enough to make the diversion from landfill worth while? Essentially, is small scale plastic recycling better for the planet overall than not consuming the energy it takes to do so? I think a good option might be large scale recycling of PLA and PETG, but I doubt that can be done in many places. Really well made video, Doc!

Oh man for the cost of these machines you'd think they would have a bit more of an elegant setup. Look how much stuff ends up outside of the hopper. Also why not just have the secondary shredder underneath the primary one? It could be driven with gears. Very odd to make you babysit a process like this.

Hey you bro I have suggestion about a new subject machine making powder iron

societal and technological innovations needed to make recycling of failed prints: lower prices for these machines or central recycling, where manufacturers buy your failed prints back. But generally speaking it has its charme to recycle material for yourself

Plastic bottles shrink when heated. When they shrink, they also thicken. You may be able to shred plastic bottles far easier if you heat them before shredding. Thicker shredded pieces may also feed better, so it worth trying to heat the bottles to shrink before shredding.

according to me, the best way to recycle the filament waste is to supply it to the recycler. They have a system in place. There are hundreds of products that can be made from melting the plastic, it is absolutely not necessary to make recycled filaments that are subpar and useful for hobbyists only.

Could you send a handful of samples to CNC kitchen and have him test the mechanical properties of recycled filament?

How had is it to add some glycol to your PET? Is it like off-the-scale chemistry?

get yourself a panini press and turn your household recycleable plastics (bottles) into flat pieces first before sending them into the shredder. :) And plastics that are not good for 3d printing can still be turned into feedstock for cnc machining or straight into cast/moulded parts.

The reclaimer needs a baymax sticker saying "I am not fast"

Wow Great ~!!!

Well, that takes care of any delusions I might have had about doing something with the poop! ;) Excellent conveyance of this bit of knowledge. Thanks so much.

Could you press and heat stacks of PET bottles into 5mm thick sheets before grinding so that they grind to chunks rather than flakes? Could be tried with a panini toaster and two sheetd of baking parchment.

Hi, Dr. D-Flo. I have been interested in filament recycling since I began to print several years ago. Now I understand it is not possible to recycle PLA indefinitely due to the degrading problems. But to PET, I have a couple of ideas I think might work but I don't have the resources to try. 1. Like the idea to produce optical fiber, melting a large amount of PET in a melting chamber or through several melting chambers with different temperature settings from softing to melting. Each Chamber has blender inside to mix the material. Then, either use gravity or pressing the melted PET through a nozzle on the bottom to achieve certain diameters filament. 2. Or, melt a large amount of the PET firstly and then cool it down into a big cylinder-shaped block. After that put the block on a lathe and use certain shaped cutter, for example a U shaped cutter, to mechanically cut down a long thread of filament. Either way will save the hassle due to the granulating the pet material. Of course, large scale of recycling PET has already been a huge industry. These two methods I think could be possible for individuals to practice. What do you think? I used to think PLA printing will be the future but now I feel like I am producing a lot of waste from failed print to the skirt. And all the items I print today will eventually become some land fill one day. And the worst part is there is no way to truly recycle it but only dilute with new material. The only way I can think of complete "decomposing" PLA is to burn them in a furnace of some power plant. Besides, I think even if the government taxes PLA to encourage recycling, those online platform like Temu or AliExpress will be flooded with untaxed and cheap imported PLA from China. I kind of feel bad to print anything non-functional now.

This is a fantastic video and you weren't joking about being expensive for hobbyists. Just $13,000 lol

I love working with PETG, does it recycle as well as PET, or does the Glycol cause it to degrade faster?

Would be a cool to see this process automated at this scale where possible...

Has anyone at your Makerspace ever tried printing regrind with a pellet extruder? I'm genuinely surprised I haven't seen this tried. I would imagine it would be difficult, like anything else, but one would think that it would be worth it to skip a few steps. Even if the amount of regrind to fresh pellet was low, I would think it would be usefull.

all this is done at a makerspace? thats really cool!! there are none by me and i want to go to one. where is this one?

really nice!! about the PET, is it possible to do a pultrusion first and the make pellets out of it and then extrude it for filament? or is just to much time and energy wasted?

What about recycling Bambu Lab printer AMS poop without those pre-processing? If the result is positive, that might be good investment for tinker.

It's a little surprising the reclaimer isn't designed in a vertically staggered layout so you can go from large to small granular sizing without having to manually reload the hopper.

If you make plastic slabs on a press (like brothers make UKposts streamers ) it does not matter all these things ,also a panini press with teflon sheets is what is used with bottle caps to make slabs I later make into knife handles has been fun and I get marble looking plastic

first off, Great video and very well explained. way too expensive for the hobbyist and very specific for the filament type separation. What I think would be interesting to know is if there is a way to mix different types of plastic. to get a hybrid filament. Again its all about temp and the thermal breakdown of the plastics. basically I have a bucket of plastic waste ranging across multiple filament types and colors. if a reasonable melting temp could be achieved that crossed all of the plastics then I could see that slurry being injection molded into something useful possibly. Now if a maker space had one of these machines and said, "bring us your sorted filament" I might sort it. and I might buy some spools if the price was right and the filament was sound. At any rate, its getting closer!