Bake your PLA and have it outperform everything else! #Filaween

Bake your PLA and have it outperform everything else! #Filaween


Ok, so I mentioned how Proto-pasta promises
extra strength and rigidity for their HTPLA line of filaments if you essentially bake
them in the oven and anneal them. This causes the typically unorganized, amorphous microstructure
of the plastic to crystallize and form larger grains that are much more of a consistent,
uniform element within themselves instead of this chaotic mess. Proto-pasta recommend
about 110°C for about an hour, which is exactly how i baked these samples of HTPLA-CF, which
have a carbon fiber content. And just for fun, i also included regular PLA, which really
doesn’t claim to be anything special, as well as E3D Edge, which is a copolyester.
I set the timer for an hour, and when i came back, the Proto-pasta HTPLA CF looked pretty
good, the vertically printed test part had warped slightly, and that was about it. The
E3D Edge copolyester was pretty much gone at this point and pretty solidly stuck to
the plate, i guess the temperature was just a bit too high for it, but what caught my
attention here was that the plain PLA looked perfectly fine. In fact, there was no trace
of it having softened or warped at all. But, who knows, maybe the copolyester just totally
underperformed here, so i didn’t i really give it a second thought.
What seems to be a common factor between all these parts is that they shrunk along the
layers and expanded perpendicularly to that, so the X and Y dimensions got smaller, while
the original Z dimension grew. I’d assume this is due to the way parts cool during printing
and the way that tension is locked into the part. The fiber-infused HTPLA only shrunk
2.5% along the layers, the plain PLA shrunk by about 5% and grew 2% in height, while the
parts printed in Edge, or what’s left of them, shrunk about 4% in X and Y and grew
roughly 3.5% in the Z direction. So, yeah, if you want to make use of an annealing process,
definitely keep that in mind.and preferably compensate for that before printing. The Proto-pasta
HTPLA-CF then went on to score exactly the same, low strength rating as in its unannealed
form, but at least demonstrated about 20% better stiffness than before, so there’s
definitely something that’s happened there. But still, I’m starting to get the feeling
that i’m doing something wrong with this CF filament, as, i mean, it prints nicely,
but doesn’t really give any advantages strength-wise. When it comes to the heat resistance test
with boiling water, the annealed part also did significantly better than its untreated
brother, and it felt pretty much like ABS at this point, or maybe even a bit better,
where it’s not really bothered by the heat. Sure, if you put some force into it, you can
separate the layers, but you can do that even with cold ABS parts, so the annealed HTPLA
parts definitely have their strong suite here. Right. So that part was as expected. Just
on a quick note, i did get different numbers for the E3D print as well, but considering
how much it deformed, it’s not really a comparable test anymore. Sure, something happened
there as well, but it’s probably on the macroscopic level where you just have the
layers welded together much better now. Now, this next part blew my mind just a tiny
bit. Everything that worked for the HTPLA also works for the dime-a-dozen, standard
PLA. And with even better results than with the carbon filled type, actually. Strength
saw about a 40% increase over the untreated part, stiffness increased about 25% and temperature
stability was as good as i just described for the HTPLA part. This means, as long as
you can compensate for the shrinkage and, you know, maybe any warp you might see with
thinner details, this test result makes the heat treated, standard PLA the best performing
material in the entire #Filaween test series yet. This was unexpected. So as it stands
right now, if you need stiff, high tensile strength parts with excellent heat resistance
and don’t mind the extra step of annealing them, plain old PLA might just be the perfect
material for that. But of course, this is just a single data point yet and doesn’t
mean that this will work for every single material. There might also be other downsides,
something like a higher tendency to crack over time or a faster degradation in wet environments,
i don’t know, but i’d appreciate your input on this. If you decide to try annealing
parts yourself, leave a comment below on how it went for you and if you’ve got any other
tips to share, don’t hesitate to let me know.

77 thoughts on “Bake your PLA and have it outperform everything else! #Filaween

  1. Hi Thomas are you making also german videos? Cause i am german and i would defenetly like it more to hear some german language 😀

    LG Thomas 😀

  2. There is not only annealing, but the heat remelts all material, erasing the cracks / boundaries between Z layers, so it becomes more "one", like a solid piece that was cast and cooled at the same time. Remelting the entire piece at once.

  3. I'd love it if you did more on this. Tests for how consistent the shrinkage is would be a great start, and testing a variety of temperatures and times would be good too. I'm curious whether short cycles of heating to the glass transition temperature, then cooling, then heating again might reduce the amount of shrinkage seen or whether it would just worsen overall results.

    I'd do this myself, but I don't have a toaster oven that goes to low enough temperatures, and my printer has problems I'm still working out.

  4. Does baking the PLA damage the oven/make it dangerous for food? I know that with reballing BGA chips in an oven (which doesn't really work anyways) it makes the oven unsafe for food.

  5. Yanking on a part with a scale attached is worthless. Had you taken the time to progressively stack weight, useful data may have resulted. What were you thinking?

  6. Considering the load you applied was not axial, your stresses at the point where it broke are going to be different at the point it broke at.

  7. How about annealing the parts in boiling water? Seems easier than putting them in the oven, just pour boiling water into a bowl, put your parts in the water and wait for the water to cool down? Should give a very even cooling too, right?
    Also your part would only experience around 20% of the gravitational stresses it would in the oven (Assuming you don't have large pockets of air making your part float). This would be great for intricate parts which might deform in the oven. Getting rid of air pockets might be difficult though, but probably not necessary since you can probably weigh them down without damaging them.

  8. The carbon fiber reinforced parts did not actually anneal at 110C, the fact that they are black means that they actually end up somewhere between the temperature of the air and the temperature of the heater elements., as a result of their high emissivity. This may also have made the green part get hotter as well. In order to fix this issue, I have wrapped parts in aluminum foil to ensure that they are not being directly hit by the radiation from the heating coils.

  9. Hello, Thomas. Thank you for your video. You are not doing anything wrong with the PLA+CF. The CF do not improve the strenght of the PLA in this case. We have a paper on this material. If you wish to see it, please google "Experimental characterization and micrography of 3D printed PLA and PLA reinforced with short carbon fibers" , by Ferreira et al. Cheers, all the best.

  10. "oh cool, this will make my part stronger"
    puts part in oven
    "it will shrink by about 5%"
    takes part out of oven, checks fitment, prints new part at 105.3%

  11. I'm sure you get tired of replying to comments all day long but I do have a couple questions that I would be gracious if you answered. First, your video makes a mention of a "pull test" or more specifically a tensile load test, and I am wondering why you only showed the bending behavior in your video. Second, in your video you use the mass as a representation of the strength of the part when you really should have used the stress (von-mises, normal, etc.) so we can more closely compare to tested values in trusted journals. Lastly, with regards to the orientation of the print was that orientation always consistent in your strength tests? Like the side you printed on the bed was it always facing down in your tests? Surely you can appreciate that there is a thermal gradient across the print piece that would cause residual stresses and have an effect on the maximum load a piece could attain.
    Something I would like to see would be a print/ anneal where you print the part, remove the part and place it in your oven face-side down (opposite orientation) because typically annealing is performed to relax a material in order to remove the residual stresses from manufacturing.

  12. So I could possibly print a coffee cup out of plain PLA, anneal it, and NOT end up with a lap full of hot coffee? I'm gonna have to try this.

  13. What if you bake an item in a cube of alabaster or some SRS investment powder? To the melting point. Will it not be as sturdy as a casted one?

  14. This comment comes from completely outside the 3d printing world. But crystalization can be improved by slow cooling slower the stronger

  15. Interesting data. Would like to see a lab do some research. On the other hand, I'd try this as well but my oven only cooks in Fahrenheit. .. :0 (

  16. I gotta say I've been LOVING eSun's PLA Pro/PLA+ lately. For its relatively cheap price I've been astounded by its performance and layer bonding….and even if it's not "stronger" you can tell it's many times less brittle. Pieces that would ordinarily suddenly fail with breakage instead bend a tad. And it's a few bucks cheaper than regular hatchbox PLA on amazon. I've gone through two fulls spools of each and I like the eSun PLA+!

  17. Hey Thomas!

    I'm an undergraduate researcher with Mississippi State University who's currently studying the effects of annealing on standard PLA printed parts. The purpose for this is, as you likely know, to increase viability of additively manufactured parts that are to be put under moderate levels of stress, since the additive method of manufacturing is, without a doubt, the least wasteful manufacturing method. I wanted to thank you for taking a scientific approach to this. While putting together my research literature I have found very few sources that actually include scientific data in their observations and findings on the particular topic of additive PLA annealing. I would also like to ask if you would mind letting me reference this video in my final report and presentation.

    Thanks!

    Ryan

  18. There is no quicker way to destroy an expensive print than to cook it in the oven. I can't even put a PLA print in the heat on my back porch without it warping. I tried to level out a warped enclosure one time in the oven and it fell in on itself real quick even at 170F. You guys must know something secret?

  19. I tested normal PLA and petg for a quad build and wasn't happy with either then heard or the tempered/ annealed PLA I gave that a try and is far superior. To get round the warping, when it's cooling a place a heavy object on the top and it flattens it back to normal so in the end it's only a little smaller than the original piece and the minor shrinkage is accounted for. End result is a far stronger and heat resistant quadcopter especially the arms

  20. Maybe it's due to the carbon fibers suspended in the PLA that still promote many smaller crystals to form. Where plain PLA would benefit more from annealing as it would have larger and fewer crystals on average.

  21. How come the infrared thermometer says 110° when the oven was set to about 180° ?

    Can't get my head quite around that.

    Maybe a little less heat and heating up in steps would have/could have helped with shrinkage?

    Please do a follow up video!

    And please try to compensate for shrinkage beforehand – would love to see if that works with more complex parts where one would actually need and use the increased mechanical properties.

    Thanks

  22. You should try with several steps in the annealing process : start with a 70C cession, then 85, then 100, and you may even try 110C after that. The shrinkage will still be quite present, but you should avoid any major deformations.

  23. FYI: wood shrinks in the opposite way, more or less, when drying. it's different in all three dimensions. wood hardly shrinks at all in the main axis of the fibers. but here's the kicker: wood shrinks more perpendicular to the tree rings than it does parallel to the rings. that's why plainsawn (when rings tend to run the breadth of the board) tends to warp into a half-moon cross section, as the rings are circular. I know it's not relevant, but I think it's cool.

  24. Your parts stiffness increased, but the Yield point stayed the same. This is a great result! I point at the example of ductile steel vs plain carbon steel. why would I want a weaker steel aka ductile then a stronger steel plain carbon steel. well ductile will reach its weaker yield point without deforming, or bending, at that point it breaks. where plain carbon steel will deform/bend and keep that shape without yielding. this is problematic as clearances in mechanical parts change, and don't bring rise to the deformation. If i was making a gear/bearing in PLA. I would opt for the stiffness vs the flexibility. If i was making a snap cover plate, I would want the flexibility for my clips. Thanks for the video!

  25. Does the process have to be all or nothing? What about hybrid processes that take advantage of the material properties while preserving the shape such as limited exposure to a chemical followed immediately by forced air (unheated / heated) to turn off the chemical process by evaporation?

  26. Wow, I had no idea the plastic was this bad… pouring hot water over it and it bends like candy….now i almost regret ordering a printer…

  27. Pretty sure this is called sintering. Allows the part to melt and bind together better. I was wondering if this would work.
    Thank you!!

  28. I wonder, could you encase the parts in plaster before baking to maintain their dimensions? Would that allow you to bake them at a higher temperature? (don't forget to vibrate out air bubbles from the plaster.)

  29. Hello, nice and interesting video thank you. Did you try to see if there is expansions with a 100% infill object? Thanks 🙂

  30. This XY shrinkage could be an interesting property if you want to heat-shrink a part around a metal part for example. No glue needed and better strength.

  31. You’re not doing anything wrong with the CF filament. The carbon fibers aren’t there for increased strength, but increased stiffness, and only in the print direction as the fibers align with it.

  32. How do you anneal a part that just deforms during annealing ? I print round objects that just flatten during the annealing process …

  33. Is there no way to add something like a stran carbon tube fiber or any strong tensile strength string in the middle like a cable does . Soft out side hard inside .

  34. Hey Thomas, should you review the case of Annealing PLAs, you should definitely try quenching it like Alex Kenis did 🙂

  35. Carbon is like wood where it has a grain structure. Especially when printing it vertically. If you printed this part horizontally the carbon should out preform the other plastics. Of couse this is for regular carbon fiber. Idk if the same applies to printed parts. But having your grain aligned with your forces properly should add strength in the dimensions you need while it will be weaker in the other dimensions.

  36. I anealed an irregular shaped part in a pan full of white rice to support it to reduce warping and it seemed to work rather well

  37. I'm triing to print RC quadcopter parts and frames, and CF-nylon and Taulman910 / 645 seems to be a good choices for certain designs, but layer adhesion seems to bee a weak point most cases. I wonder if I bake the finished print as a post-process, maybe putting some weight on top (if the design is flat) would help this issue – or just ruin the print (deforming, or certain chemicals going be to removed)? Thanks in advance

  38. Big problem for me, I don't have a oven that can go that low of a temperature, what should I do, I don't want to buy a mini oven cause they are expensive, I really hope someone has an idea how I can do this

  39. Have you tried to boil the PLA in water for a while? In my test that seem to give the same effect and takes 5 min instead of 30. I could do it in 2 min using water that's already boiling but it seem to deform more then.

Leave a Reply

Your email address will not be published. Required fields are marked *