Lazy annealing of PLA (covered on heated bed after 3D printing)

Рет қаралды 13,963

Күн бұрын

Пікірлер: 54

@AB-eg3ei Жыл бұрын

I´m annealing a lot of PLA with the "lazy method", but 100 degrees straight from the start is too high as the PLA will get very soft initially. What works best for me is to heat up the bed to 80 degrees for one hour. The parts will shrink minimally and will not warp at all. If I want no dimensional change at all, I use volcano PLA. After that treatment the parts are heat resistant enough to withstand boiling water without any deformation . If I had a very delicate part with overhangs, I would heat the bed to only 70 degrees for around half an hour and then proceed with 80 degrees for another hour. Why? - if you start with a lower temperature just above the glass transition temperature the parts will gain some temperature resistance without getting too soft. The "partly annealed" part will then be temperature resistant enough to go for a higher temperature and so on.... About the annealing in water (I tried that too) I can say that it works , but you will need a very tightly controlled heater and thermometer and keep the water at the same 80-85 degrees in the beginning. Putting the part in 100 degrees water will cause the part to warp immediatly, so thats not an option. There is one more thing to consider (I´ve tested this with thin walled PLA test parts printed from different brands PLA and PLA+): Some of the PLA variants that are fine when annealed with the 80 degrees dry method will get super brittle when annealed in water. I don´t know why that is, but my guess would be that some filaments react badly to hydrolysis ??? (any chemists around here ;) )

@AB-eg3ei Жыл бұрын

@@polycrystallinecandy the pieces I anneal are usually little tubes with a slit on one side, diameter and height are around 30mm, wall thickness around 1.5mm. So I can´t say much about parts with infill. What is important though is not to anneal the parts for too long. If you just let the parts sit on your printer bed for too many hours, it will warp even if you annealed with a lower temperature. So I guess the sweetspot is were you get the heat resistance you need with the lowest impact concerning shrinkage and warping.

@AB-eg3ei Жыл бұрын

One more thing that I forgot to mention, I did all the annealing with the original ender 5 pro build surface. Its these flexible sheets with (I guess) a polycarbonate layer on top. PLA sticks very well to this, so even after the annealing parts are still stuck to this, they won´t self release. That might also be a big factor why this works so well for me.

@mypd1991 Жыл бұрын

this should be his next video, what small temperature increase to final temp is the best.

@squidcaps4308 Жыл бұрын

There is a g-code for that... Quite easy to program an annealing process. It could be that going in steps, 50C, cool down, 60C cool down and so on would preserve dimensional accuracy the best. Also, the slower the plastic cools down while printing improves heat resistance. That is when the plastic becomes amorphous in the first place, when it is cooled down in a second, freezing all polymers in place. Once it is heated, it changes semicrystalline, the polymers can organize and pack themselves more efficient.. So, it makes sense that doing it in steps, or just very slow heating would work better. There is very simply explanation for PLA annealed in water, i just wrote a comment about it, so i'll copypaste: "PLA, heat and water do not mix. It starts to hydrolyze and becomes brittle. The polymers get shorter. So, annealing in boiling water is not recommended. Humidity should be kept away when annealing, the closer to zero the better." Poly-Lactic Acid is made from glucose that is converted to lactic acid. Then we remove basically one H2O from it, that forms monomers. Then we apply heat in ABSENCE of water to snap those monomers end to end, to form polymers. So, PLA really wants that H2O back. Apply heat to decrease energy needed for a reaction to happen, give it water sources and... it will hydrolyze.

@WillyFooLiveStudios 28 күн бұрын

Thanks will try out.. got ai to help me create gcode ... copy and pasting here if anybody else needs ; Initial bed preheat (assuming bed starts at room temperature) M190 S40 # Wait for bed to reach 40C ; Annealing Steps (heat up, dwell, cool down cycles) M190 S60 # Heat up to 60C G4 S1800 ; Dwell for 30 minutes at 60C M190 S55 # Cool down to 55C G4 S300 ; Pause for 5 minutes M190 S50 # Cool down to 50C G4 S300 ; Pause for 5 minutes M190 S45 # Cool down to 45C G4 S300 ; Pause for 5 minutes M190 S40 # Cool down to 40C M190 S70 # Heat up to 70C G4 S3600 ; Dwell for 1 hour at 70C M190 S65 # Cool down to 65C G4 S300 ; Pause for 5 minutes M190 S60 # Cool down to 60C G4 S300 ; Pause for 5 minutes M190 S55 # Cool down to 55C G4 S300 ; Pause for 5 minutes M190 S50 # Cool down to 50C G4 S300 ; Pause for 5 minutes M190 S45 # Cool down to 45C G4 S300 ; Pause for 5 minutes M190 S40 # Cool down to 40C M190 S80 # Heat up to 80C G4 S7200 ; Dwell for 2 hours at 80C M190 S75 # Cool down to 75C G4 S300 ; Pause for 5 minutes M190 S70 # Cool down to 70C G4 S300 ; Pause for 5 minutes M190 S65 # Cool down to 65C G4 S300 ; Pause for 5 minutes M190 S60 # Cool down to 60C G4 S300 ; Pause for 5 minutes M190 S55 # Cool down to 55C G4 S300 ; Pause for 5 minutes M190 S50 # Cool down to 50C G4 S300 ; Pause for 5 minutes M190 S45 # Cool down to 45C G4 S300 ; Pause for 5 minutes M190 S40 # Cool down to 40C ; End of annealing, play a shorter melody M300 S440 P200 ; A4 M300 S494 P200 ; B4 M300 S523 P400 ; C5 (longer note) ; End of G-code (bed will be at 40C)

@spongecounter Жыл бұрын

That was really interesting, Igor. Thanks. Testing the annealing temps in 10 deg increments would be informative. It would be great if the hot water reduces the warping. Looking forward to that video.

@BillyNoMate Жыл бұрын

Annealing with print bed is great idea. i use this method to dry my filament. Heck! I even cook sous vide steak with my print bed 😁

@Mwwwwwwwwe Жыл бұрын

Nice! Ive used my hotbed to unglue my broken tablet screen also to dry out a phone which fell in a puddle(after washing it with distilled water)

@Mikehatespigs Жыл бұрын

@@Mwwwwwwwwe surprised it still works next time use 90 percent or better rubbing alcohol on your phone to rinse it takes water out as well that's how they fix keyboard that have been spilled on is my soaking in rubbing alcohol

@Mwwwwwwwwe Жыл бұрын

@mikealnutt360 distilled water is non conductive-(doesn't have any disolved mineral salts ) to short out electrics also non corrosive. I've had Isopropyl ruin lcds before

@ianhoolihan2396 Жыл бұрын

Anecdotally, i have annealed in a sous vide circulator with the part in a plastic bag and also in a jar packed with salt. The plastic bag only had deflection in thin walls and dimensional changes. The salt had no deflection in thin walls but still dimensuonal changes.

@dempa3 Жыл бұрын

Thank you for trying out "lazy annealing"! Your tests are quite impressive! I use it for increased heat resistance,and so far I'm satisfied. I haven't tried boiling water. There are also many good ideas in this comment section, which I'm curious to try out. As I mentioned previously, I think that many of us are curious about remelting in fine grains, and a comparison to the "transparent fdm settings" featured in a cnc kitchen video from 10 months ago. But it is definitely a lot of work to test it out.

@guyrichardson9477 Жыл бұрын

Very interesting and a nice video. I regularly anneal pla to improve temperature performance. I use a water bath 75C and near 90% infill parts. Put hot water in a pot, add cold water to bring down to temperatures, put parts in, cover, come back in an hour. I have had good results with fiberlogy impact pla. Only get 1% shrinkage and heat resistant >110C. The buoyancy of the parts in the water help prevent warping.

@MyTechFun Жыл бұрын

I just started the water test, 95C but this looks too much, object still deforms.

@mrnlce7939 Жыл бұрын

I don't know about water annealing but I've heard good things about salt annealing. However the salt annealing adds a texture to the part. Maybe with a finer medium it would work better. Great video. Keep up the good work.

@daliasprints9798 Жыл бұрын

The salt approach isn't (just) annealing but remelting to get isotropic part. Depending on how it cools, it may or may not anneal afterwards.

@Dramaican88 Жыл бұрын

Not sure what the theory behind the boiling water sous vide method is. It does not provide support really to prevent warping or deformation. Compared to the lazy method the heating would be more uniform, because here with your test the heat conductivity difference was big. I think the main reason that the impact specimen warped is that one side was touching a high thermal conductivity print surface, while the top side was warmed by the trapped air only and without airflow. Parts suspended in the middle of an oven get more uniform heating. To prevent deformation while annealing there are two known solutions. One is to burry the prints in a fine powder material that does not melt or react with the plastic, like sand or salt. The other is to use filled materials. Carbon fiber, glass fiber or mineral filled materials will deform less during annealing. This is because the main cause of the deformation is that there are stresses that build up between the polymer chains during the printing process and heating up the material and softening it, helps release those stresses. That is why on the Z the parts expand, it is stress release. Carbon fiber nylons can be annealed and PET CF can also be annealed like the new PET CF from UltiMaker, PET CF from Luvocom, PET CF from Phaetus, Raise3D, BambuLab and QIDI. Pay attention that only PET materials without the glycol modification can be annealed. PETG and PETG CF can't be annealed effectively because glycol reduces the crystalinity of the material.

@lizrrdbreath Жыл бұрын

Annealing Nylon in boiling water is something that people do in the combat robotics community because it not only anneals the part but rehydrates with the theory being that it increases the impact resistance of the part. I don't know about other filaments but I would definitely be curious to see testing of PLA, ABS, PETG, Nylon, PC, and maybe even TPU? though I know that TPU doesn't work well with your typical testing methods.

@squidcaps4308 Жыл бұрын

PLA can't be boiled, it will hydrolyze and become brittle. Any application of heat should be done in low humidity environment.

@squidcaps4308 Жыл бұрын

PLA, heat and water do not mix. It starts to hydrolyze and becomes brittle. The polymers get shorter. So, annealing in boiling water is not recommended. Humidity should be kept away when annealing, the closer to zero the better. Salt annealing works well. Also, i have tested casting PLA, which is not easy as it is so viscous, but the results were amazing. Temperature resistance comes as a side-effect, and i learned that annealed, uniform PLA is extremely hard and tough material. My mind was blown. I made a mold from wood, since we are "casting" at relatively low temps, sprayed temperature resistant paint as mold release (worked amazingly well, it adheres to the plastic permanently with very nice coat quality), melted some scrap PLA with a heat gun, popped in the oven for an hour, took it out, closed the mold which pushes plastic to really fill the mold, and let it cool down on its own. The "technique" requires two sided molds, like injection molding, you just insert the plastic yourself and give a lot of room for flashing. My models had a flat bottom, which meant my upper mold was just flat piece of metal, clamped to the wooden mold.

@CareyBarnett Жыл бұрын

I postulate that annealing process will, to some extent, remelt the layer welds, and they may re-weld inconsistently, giving unpredictable mechanical strength results to the parts. I like the staged annealing idea. That should mitigate some of the unpredictability.

@KingSoftwareWizard Жыл бұрын

The thought of annealing in boiling water makes me wonder if it would be worth trying it under pressure. The 'Instant Pot' and clones are readily available and relatively inexpensive.

@daliasprints9798 Жыл бұрын

Yes, to prevent air pockets/hollow infill from warping the part with unequal pressure you want slow heating/cooling in a sealed chamber.

@dtaggartofRTD Жыл бұрын

I've done similar while restraining the movement of the part in some manner. Minimizes the dimensional changes while providing the benefits of annealing. EDIT: Can't say I've heard of PLA being annealed that way, but I've seen it done with nylon. A variation that worked really well was to anneal in an oil. The oil kept the humidity out during the annealing process and provided a surface treatment that prevented future adsorption.

@AwesomeBrixx Жыл бұрын

I love your comprehensive testing! I think the biggest use case (like you said in the video) would definitely be temperature resistance

@Mark_5150 Жыл бұрын

I wonder if the warping is due to the inconsistent heating from the print bed, from the bottom up, perhaps water would work better, heating evenly. Or is the warping from the cool down process because the air would cool faster than the bed? Next time, try a clear glass bowl. ;)

@DaveEtchells Жыл бұрын

Another great set of tests, thanks very much for your continued careful, meticulous work! (Never heard of boiling water before, I’d be interested in learning about it.)

@earhornjones Жыл бұрын

Beautifully tested. I learned some good information from this. Thank you!

@75keg75 Жыл бұрын

Is it worth making a negative mould that you place over the model to control the warping while it annealing. Obviously a mould or form would have to be higher transition temp than part to avoid warping.m itself. It would be interesting see how eiger (mark forged) scales the part to account for warping, ie if z is 1.05 larger then they make it at scale 0.952 so final part is 1.0 and like wise length wise and width too. So the “green” print would be a really warped shape vs final sintered/ anealled part. Cadmould is a software that has modules to compensate for warping. It’s all Price on asking so won’t be cheap…

@CareyBarnett Жыл бұрын

I would think this comes down to the cost benefit analysis for each part. If you’re doing this professionally, build the cost into the price, but you’d better be getting guaranteeable results.

@tek9058 Жыл бұрын

I think focusing more on slicers to create holes in T shapes in walls/infill then inject filament after few layers. This could create interlocking patterns and end up very strong

@marcus3d Жыл бұрын

You could also try annealing inside tightly packed, fine-grained sand.

@a1hamer Жыл бұрын

Or fine milled salt ;)

@daliasprints9798 Жыл бұрын

There is a plausible mechanism for annealing to make layer adhesion weaker: if the layer adhesion is partly relying on mechanical interlocking of texture like a hot glue gun would do, rather than actually welding the polymer. I find this is what happens when printing at recommended temperatures like 200-220 rather than 260+. In this case, warping would reduce layer adhesion the same way cooling breakd bed adhesion.

@Gengh13 Жыл бұрын

I would love to see a water annealing test, as far as I know it should minimize warping.

@squidcaps4308 Жыл бұрын

PLA becomes brittle when cooked.

@ioscaleb 9 ай бұрын

Very thorough -- thanks for this!

@NickBR57 Жыл бұрын

Interesting as always. Regarding deformation and warping, have you done any experiments (would like a link if you have) on warping and/or stress deformation with different infill patterns? Thanks for another great experiment.

@CareyBarnett Жыл бұрын

Sounds like a good ‘reason’ to buy a sous vide circulator 😊

@daliasprints9798 Жыл бұрын

You should probably try with a bed surface that maintains adhesion under changes in temperature rather than these things designed to release with thermal contraction.

@mab4110 Жыл бұрын

sous vide annealing sounds delicious

@SnakeOilDev Жыл бұрын

My friend did the boiling method with ABS and it increase the melting temp a little. But i never tried it myself.

@shadyb Жыл бұрын

I like videos like this. Good job!

@geraldsaunders2400 Жыл бұрын

Have you tried annealing inside a plaster of paris mold? I have heard of using salt and sand but these are not dimensionally accurate. Thought making a plaster of paris mold or sleeve might solve this... By the way, I love your work!