There are numerous 3D printing materials on
the market but PLA, PETG and ABS or its very
similar counterpart ASA are probably still
the most common ones used. I took these 3
materials from the Prusament lineup and compared
them side by side. Let’s find out how they
print, look, and perform in mechanical and
thermal tests! Guten Tag everybody, I’m
Stefan and welcome to CNC Kitchen.
Even though you can nowadays get almost any
thermoplastic as a 3D printing filament PLA,
PETG and ABS are still the most common ones
used. PLA is the most printed material due
to being very easy to print without any significant
smell but with the downside of being a bit
brittle and thermally not very resistant.
ABS is slowly replaced by a very similar material
which is ASA, that performs almost the same,
but with the added benefit of being UV resistant,
having less warping tendency and lower odor.
PETG has been on the uprise since a couple
of years and is praised for having the ease
of printing of PLA but being less brittle
and thermally more resistant. But how do those
materials really perform in a side by side
comparison and is there “a” best material.
I gotta say at this point that almost every
material from every manufacturer will behave
differently because even though it says PLA,
PETG or ASA on the box, there isn’t just
one PLA, one PETG or one ASA. Depending on
manufacturer, the raw material, compositions
and additives deviate and that will influence
printability as well as performance and this
is also why there are $10 PLAs as well as
$50 PLAs on the market. Also the printer,
print setting and environment changes properties.
I can’t cover everything but I chose Prusas
own material lineup for a reason, because
once, they cover all of those materials, are
all really decently priced and due to the
amount of QA they perform shouldn’t scatter
that much from batch to batch or even roll
to roll! They even check material color to
avoid having different hues when doing a project
where you need more than one roll. Since Prusa
also provides their whole own ecosystem with
their Original Prusa Printers, PrusaSlicer
and the Prusament it doesn’t require me
to tune in each material on my own because
they already did a pretty great job in that
regard. And just to be clear, this material
works just as well on any other printer that
uses 1.75mm filament!
So what I’ve done is, that I printed quality
parts and real test samples for all 3 types
of Prusament and we’ll be taking a look
at them side by side to see how they perform
in each of these categories: Price, Printability,
Printing Quality, Static Strength and Layer
adhesion, Ductility, Stiffness, Impact Resistance
and Thermal Resistance.
What materials are you usually using for your
projects and why? Please let me know down
in the comments!
All spools come in a nice cardboard box and
are sealed in thick plastic bags that are
resealable for storage and include some desiccant.
The spool itself looks unique with the hexagon
cutouts that don’t only reduce material
usage for less weight and shipping costs but
also give you plenty of holes to poke the
ends of your filament through. It features
manufacturing date and print settings, as
well as a QR code that lets you track each
single spool produced and provides QC information.
The 
only issue I had was with these slots in the
center hole that are probably used for indexing
during prodcution, but which caught on a cheap
spool holder that I use on top of my printing
enclosure and that resulted in printing artefacts.
Definitely use a round one here. Prusa talked
quite a bit about their perfect winding and
it does really look nice and should reduce
tangles during printing.
A kilo of Prusament PLA sells for €25, PETG
and ASA sell for €30 though the ASA spool
only contains 850g. The reason for that is
probably not because they are greedy but ASA
has a density 15% lower than the other so
1kg of material just wouldn’t fit on a spool
but since all spools still contain around
330m of filament you can still print the same
amount. In the end that makes a kilo price
of €25 for PLA, €30 for PETG and €35
for ASA. Taking the density into consideration,
PETG and ASA both end up at 9 cents a meter,
whereas PLA is 7.5 cents a meter. In Europe
you can directly buy it from Prusas webstore,
in the US it’s available on Amazon including
free Prime shipping. So in the end it’s
not super cheap but still a very decent price
especially for the quality and range of colors
you’re getting. And especially inexpensive
if you compare it to materials from other
3D printer eco-systems.
All the prints were done on my Original Prusa
i3 Mk3s. I printed two print jobs with each
of the materials. One featured quality test
parts, the other one contained the samples
for material testing. I used stock settings
on a stock printer, and didn’t play around
with any parameters. All prints were done
in my office and no enclosure, I only did
one set of layer adhesion samples with ASA
in an enclosure, down in my basement, but
since it was wintertime it didn’t get much
warmer than 30°C. PLA was printed at 215°C
on the nozzle, PETG at 250°C and ASA at 260°C.
Because this might also impact layer adhesion
and print quality later, PLA used a fan of
100%, for PETG it was set to 30-50% and even
ASA was printed with 20% part cooling fan.
Parts mostly stuck quite well to the PEI coated
spring steel bed but I sometimes applied a
bit of Magigoo for challenging prints, even
though Prusa doesn’t recommend the use of
these adhesion products.
Overhangs looked great up to 55° and started
to degrade at 65°, only, and remarkably,
ASA printed those still great. Stringing and
small details was also very similar with only
the PETG getting a little worse right at the
tips. PLA performed best at the bridging test,
PETG a little worse and this was the only
time that ASA came last. All 3DBenchies looked
really good. The Army-green PLA and the Jet
Black PETG had a shiny finish, the Orange
ASA, which color I actually adore, was matte.
The only thing I was able to see, was that
the PETG was a little stringy which is common
for that material and the ASA part had a small
step on the height of the floor of the 3D
Benchy which is a good indication that it
contracts more during cooling than the others.
Due to the usage of cooling, even the chimney
on the ASA part looked great which is often
a challenge with that material group. All
in all that means, if you have a good material
to start with and tune it properly PLA, PETG
and ASA can all produce gorgeous prints.
Next, let’s continue with the interesting
part and this is the mechanical tests. Since
this shouldn’t get crazy technical, I compared
the static strength of the materials not with
standardized dog bone test samples but printed
a couple of my test hooks where we can analyze
the material strength of a lying part and
the layer adhesion with the hooks printed
vertically. All parts were printed with the
same wall and infill settings. I mounted the
parts one after the other in my DIY universal
test machine and loaded them at a constant
speed to remove the human factor. Let’s
start with the horizontal hooks. The PLA part
failed quite brutally at 73kg of load. There
was some yielding, but when it went, it was
quite suddenly. Next came the ASA part with
57kg of maximum force. It failed rather similarly
with also a bit of yielding but then cracked
instantaneously. The PETG part was the weakest
with 55kg of failure load. In contrast to
the others, and this is quite an advantage
of PETG, it never snapped through and just
stretched and stretched which make parts out
of this material more robust.
In order to find out how good the layers bond
together I’ve tested the same hook with
similar wall thickness and infill only printed
standing. As expected, the vertical parts
failed earlier than the horizontal ones. The
average failure load of the PLA hooks was
40kg, which is 55% of the ones printed lying.
Quite a knock down but totally in the expected
range. Next came the PETG hooks that failed
on average at 25kg of load which is 46% of
the horizontal ones. Again, still in the expected
range but you can already see how much stronger
PLA parts can be. Next came the ASA parts
that snapped on average at 17kg which is only
29% of the reference load. ASA similar to
ABS wants to be printed at best in a heated
chamber without cooling, otherwise layer adhesion
can suffer. So there is a trade-off between
nice looking parts and well performing parts.
I, at least tried what difference it makes
if the material is printed in an enclosure.
Due to the outside temperatures I didn’t
get it to warm up more that to around 30°C,
so still not ideal and might be a good idea
for another investigation. Still, those hooks
were able to bear 20kg of load which is 20%
more than the parts without the chamber, so
definitely think about elevated chamber temperatures
when printing ASA or similar.
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Next, let’s take a look at the stiffness
of the materials, because this might sometimes
be a factor you’re looking for. Also don’t
mix up strength and stiffness of the material.
Strength tells you how much stress a material
can take before failing, stiffness is the
resistance against a deformation. The force
plots of our hooks already give us an indication
which material is stiffer due to the initial
slope of the curve. A stiff material has a
steeper slope because at the same level of
deformation it resists with more reaction
force. PLA seems to be the stiffest, ASA is
in the middle and PETG is the least stiff.
In order to get a numeric value of the stiffness
I performed a 3-point bending test with all
materials where I loaded a fully dense bar
with increasing weights and recorded the deformation.
Using the dimensions of the bar, the recorded
deformation and the applied weight I can now
calculate the bending modulus of the material.
As expected, PLA is really the stiffest with
a bending modulus of 3300MPa, next comes ASA
with 2300MPa and with only 70% of the stiffness
of PLA, PETG is the most flexible material
of the 3 with only 1900MPa, really interesting!
With the hook test we’ve tested the strength
of the materials when they are slowly loaded,
though in some cases it might be interesting
for you how the parts behave at an impact,
for example if you crash your quadcoper. In
order to test this, I performed an impact
test with notched IZOD specimens. In this
apparatus the coupons are placed in a vice
and then struck by a hammer. This impact will
use some of the kinetic energy of the hammer
so it won’t be able anymore to swing back
to the same height as it started. This can
be measured with the attached scale. PLA absorbed
on average 8% of the hammers energy which
results in an impact strength of 5kJ/m².
PETG was only a little better and absorbed
on average 14% of the kinetic energy resulting
in an impact strength of 8.6kJ/m². This is
interesting and might be counterintuitive
for some, because it behaved so ductile in
the static hook test. This just shows the
strain rate dependent behavior of the material,
so the different behavior of properties at
different loading speeds. ASA was the toughest
material and was able to absorb almost 30%
of the hammers energy resulting in an impact
strength of 18kJ/m². This is more than 3
times the value of PLA and more than 2 times
the one of PETG.
In the last test I compared the temperature
behavior of the 3 Prusament materials. I placed
them in a small jig, loaded them in the center
with a nut and placed everything in my convection
oven that was fitted with an additional thermocouple.
I tried to rise the temperature as uniformly
as possible to capture the moment when the
material starts to soften and when it finally
fails. PLA started to give at first when I
reached a temperature of 60°C and just 5°C
later it completely failed. At 80°C I started
noticing the PETG part slowly started to give
and then also totally failed 5°C later. ASA
was the most resistant and only started to
soften at 110°C and slowly kept sagging until
it wasn’t able to handle the weight anymore
at 120°C.
So in summary, all of the Prusament filaments
printed really nicely, even ASA without any
enclosure. Static strength was the highest
for PLA but it behaved way more brittle than
PETG for example. Layer adhesion was around
50% below the reference strength for PLA and
PETG only ASA was quite a bit weaker in that
regard, though printing with an enclosure
or maybe less fan might help. In terms of
stiffness, PLA again showed the highest values,
ASA came second and PETG only had 70% of the
stiffness of the winner. Impact resistance
was the lowest for PLA, next came PETG and
ASA was by far the most tough material. Under
elevated temperatures, PLA failed at first,
PETG seems to be usable up to almost 80°C
and ASA should be able to even bear boiling
temperatures. Keep in mind that this comparison
was made with the Prusament lineup. Other
brands might perform differently.
In the end, there is no best material. Every
one of them has its pros and cons! PLA is
still my go-to material due to the ease of
printing, the high strength and stiffness.
If you want to avoid the printing odor and
still a bit more hassle during printing but
need the ductility and more toughness, PETG
is a nice alternative to PLA. ASA especially
shines at higher temperatures and demanding
applications but at least without a special
setup suffers in terms of layer adhesion.
Still, due to the odor I avoid the material
if I can. So as an example, what material
of those 3 might now be suitable for a quadcoper
frame? In such a case I might still use PLA
due to it’s strength and stiffness. I wouldn’t
choose PETG because first it’s density to
strength and stiffness ratio is not great
and during an impact it’s not that much
better than PLA. ASA might be a good option
there, because it has a lower density and,
in the end, only a slightly lower weight to
strength and stiffness ratio than PLA but
is more impact resistant and thermally stable.
Still PETG is a good option if weight is not
an issue but you need a bit more toughness
and thermal stability. But in the end, you
have to choose and I’d really like to know
which materials you prefer for your projects
and why! Leave a comment down below!
Thank you for watching! I hope you learnt
something new today. If you did, then please
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auf wiedersehen and goodbye!
