3D PRINTS at LOW temperatures – How PLA, PETG, ABS, PA & PC perform at -20°C! (surprising results!)

It’s been pretty cold here in Germany this
week and I asked myself how our 3D prints can handle these low temperatures. So this is why I tested PLA, ABS, PETG, Nylon
and Polycarbonate for their performance at freezing temperatures. Guten Tag everybody, I’m Stefan and welcome
to CNC kitchen. We all know how our 3D prints handle high
temperatures and that PLA is no good over 50°C and with ABS, Nylon and Polycarbonate
you can probably go up to 100°C but I didn’t find a lot about the low temperature performance
of these materials. At least for our standard, it’s been pretty
cold this week so I thought this would make a perfect topic for a new video. For this reason, I printed test samples in
the most common 3D printing materials, tested them at ambient temperatures for our baseline
and then cooled them down to -20°C and performed the same tests again. The results were pretty interesting! I didn’t perform the whole range of tests
I usually do for my filament test series because this would have been way too much work for
the 5 different materials at the two temperatures. Therefore, I selected my trusty test hook
to assess the static strength of the material and the notched Izod test specimens for the
impact strength. This will give us and idea, how the ductility
of the 3D prints change and if they get more brittle. We’ll also get a pretty interesting overview
about the general strength of the different materials when we compare them side by side. I have to say, that your mileage will vary
depending on the brand of material you use, because even though your material is for example
also PLA based doesn’t mean that the performance will be the same. Additives the manufacturer will use for better
printability and adjusting properties might change the general material behaviour and
also the one at lower temperatures. The same is applicable for the other materials
in the test. I used Formfurura Premium PLA, Das Filament
PETG, 3dkBerlin ABS, Formfutura STYX-12 which is at PA-12 and Polymakers PCMax for my testsamples. The hooks were printed at 0.165mm layer height
with 3 perimeters 8 top and bottom layers and 30% cubic infill. The impact specimens were printed with 4 perimeters
at 0.15mm layer height and 100% infill all on my trusty, old Prusa i3 Mk2s. The baseline tests were performed at around
20°C ambient temperature. The PLA hook was the strongest, breaking at
84kg followed by the PCMax hook at 82kg. The PETG and Nylon hook failed at around 70kg
where it was interesting to see that they didn’t fail abruptly but strained quite
a lot during failure. The ABS hook was the weakest failing at 59kg. Since I know that the impact test results
usually scatter a lot I tested 3 samples for each material, where, not surprisingly the
Polycarbonate part was the strongest absorbing on average 71% of the energy of the 2J impact
hammer. The PA-12 samples absorbed 36% and ABS 30%. The das Filament PETG showed much better impact
strength than I was expecting and absorbed 21% of the energy. PLA, as expected doesn’t have a great impact
strength and was only able to absorb 6% of the hammers energy. Now we come the interesting part, the low
temperature performance. By the way, if you like the video than don’t
forget to give the video a like, share it and if you really want to support me in my
research, consider becoming a Patreon. I was facing the problem of how to cool my
samples down properly. I didn’t want to go for liquid nitrogen,
because this would have been an unrealistically low temperature. Also, my freezer is too far away from my office
that I could take all my samples from there. There I decided to go with a cooling bath
in which I stored my samples in a plastic bag that they don’t get wet. I used around a kilo of ice cubes that I partly
crushed. Then I added around half a kilo of sodium
chloride. Always remember to wear proper safety equipment
if you are working with these dangerous chemicals. I have heard that sodium chloride may lead
to severe hypertension and you don’t wanna have that. After you have mixed up everything you’ll
have a cooling bath that will stay at around -20°C for quite a while, so perfect for cooling
down my samples for the test. I know that -20°C is not the lowest temperature
you might encounter where you are living, but this was the simplest setup I could come
up with and that still will show a difference in material performance. I kept the samples in the bath for quite a
while until I was sure that they were completely cooled down and then started the impact test. I touched the samples with a double layer
of gloves to introduce as little as possible heat and performed the tests as fast as possible. Polymakers PCMax suffered quite a bit in these
low temperatures and was only able to absorb half of the energy as at ambient. Nylon also dropped from 36 to 25% during the
impact test whereas the performance of ABS didn’t suffer too much. PETG, still performing way better than I expected,
but also showed a bit less strength. The performance of PLA didn’t really change
a lot, still being quite low, but this might just be due to the resolution of my test setup. The results of the hook tests surprised me
quite a bit in the beginning, because all hooks were able to bear more load at -20°C
than at ambient temperature. It took over 100kg to get the PLA hook to
fail. Polycarbonate improved from 82 to 91kg, PETG
from 71 to 85kg Nylon from 79 to 83kg and also ABS improved by almost 20% to over 80kg
of failure load. This sounds a little counterintuitive at first
but makes sense if you know that ductility and strength usually change in opposite directions. If a material becomes less ductile, so more
brittle, the strength usually increases. Let’s for example look at the PETG sample
that strained a lot at ambient temperature but shattered at low temperatures. The test graph shows, that straining started
way later, but shortly after it started, the part failed abruptly. This was more or less the same for all of
the other materials. So, what does this mean in real life. Well, ductility is a very positive property
of material, because it makes it more robust. This means that ductile materials will start
to strain during overload therefore shift and distribute the applied loads more evenly
over the part and therefore maybe bend a little but not fail catastrophically that fast. Brittle materials might be able to bear more
load but if they get slightly overloaded fail on short notice! Though I think that this test has shown that
none of the materials completely changed its behavior at -20°C so, even though you might
not be able to expect the full performance of your part, it probably remains quite usable. The lower the temperatures will get the more
brittle and maybe unusable some materials will become, so I’d be really interested
to know how your experience with 3D prints during the winter or maybe only in your freezer
is. Have you had parts badly fail in the -40°C
Canadian winter? Please leave a comment down below. I guess I was able to show how the properties
of your 3D printed parts change at lower temperatures. If you enjoyed the video and learned something
than please leave a like and subscribe to my channel. Consider becoming a Patreon to support my
work and take a look at the other interesting videos on my channel. Thanks for watching, auf wiedersehen and until
next time!


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