Last week, we had a look at a carbon-infused PETG filament. This week, I’d like to show you two composites based on a more common thermoplastic in 3D printing: ABS. Among a whole lot of other engineering plastics, the french company Nanovia manufactures Kevlar-like aramid-fiber-infused and carbon-fiber-infused ABS 3D printing filaments. These materials promise tougher parts with less warping while being just as easy to print as regular ABS. Let’s check them out!

Lucky enough to obtain a huge pack of samples from Nanovia’s endless list of highly exotic filaments (Thanks Jacques!), I was able to run a few test prints on the carbon-fiber-infused ABS and on two colors of aramid-fiber-infused filaments. These filaments come with detailed datasheets, including exact printing parameters, which makes using them a great experience — toss the values from the sheet into your slicer and get great results right away.

Aramid Fiber ABS

The exact fiber content of this material seems to be a proprietary trade secret, but I was told it’s above 5%. According to the data sheet, one gram of the filament contains 5 million tiny aramid fibers with a diameter of about 10 µm and a mean length of 215 µm – so basically it’s dust. Taking the composite’s density of 1.08 g/cm3 into account, a bit of math and educated guessing lead me to believe that the volume-specific fiber content must be in the range of 9 % (13 % by mass). That’s a fair amount that should have a noticeable effect on the material’s properties.

Plain ABS is already valued for its toughness, but — in 3D printing — also known for its tendency to warp. Its high thermal expansion coefficient of about 70 µm/(m K) is to blame. Aramids have a slightly negative thermal expansion coefficient in the range of -2.5 µm/(m K), which helps to prevent warping issues when printing aramid fiber compounds. In contrast to carbon fibers, aramid fibers act as a thermal insulator. They also are not harmfully abrasive, making this material a great alternative for printers that cannot be equipped with a hardened steel nozzle.

Print Quality

To get an all-round impression of a material’s surface-finish, overhang- and bridging capabilities, printing a Benchy is the way to go. I printed one for each color at 255 °C with 0.2 mm layer height, and it turned out beautifully, as you can see below:

Basically, the aramid fiber ABS prints just like regular ABS. The bridges and overhangs at the Benchy’s cabin-windows worked well, so did the overhangs at the bow. All details came out nicely, and the interesting semi-matte surface finish of the uncolored, naturally yellow aramid blend is not as rough as one might expect from a fiber infused material. In the darker aramid blend, the fibrous nature of the material become more visible:

Carbon Fiber ABS

From the notes in the data sheet I conclude a volume-specific fiber content of 5 % (10 % by mass) for this filament. Just like the aramid fibers, carbon fibers lower the thermal expansion coefficient of the composite, making this a low-warp material. Carbon fibers are very abrasive, so a hardened steel nozzle is recommended when printing carbon fiber composites. Even though this filament is supposedly antistatic, it’s worth mentioning that this material is not conductive enough to print electronics. It does, however, conduct heat.

Print quality

The carbon fiber ABS also had to undergo the same Benchy-test at 255 °C and 0.2 mm layer height, with almost identical, perfect results to its aramid infused siblings. The surface finish is slightly more rough than the aramid filament but very consistent.

Resilience

While both the aramid and carbon fiber filaments produce noticeably stiffer parts than plain ABS, they are also noticeably more flexible than parts from the PETG based XT-CF20 I tested last week. Looking at the data sheet, none of their properties particularly stands out from the crowd – on first glance.

Nanovia

Aramid Fiber

ABS Nanovia

Carbon Fiber

ABS ColorFabb

XT-CF20

PETG plain

ABS

(typical) Flexural Modulus

ISO 178 / ASTM D790 2.3 GPa

printed specimen 2.7 GPa

printed specimen 6.2 GPa

molded specimen 1.9 – 2.3 GPa

molded specimen Tensile Modulus

ISO 527 / ASTM D638 2.4 GPa

printed specimen 2.7 GPa

printed specimen N/A 1.9 – 2.5 GPa

molded specimen Elongation At Break

ISO 527 / ASTM D638 7.5 %

printed specimen 10 %

printed specimen 7.5 %

molded specimen 8 – 9 %

molded specimen Glass Transition Temp. 101 °C

(213.8 °F) 101 °C

(213.8 °F) 80 °C

(176 °F) <105 °C

(221 °F)

On a second look (and a few emails), it’s due diligence for a manufacturer of engineering plastics for 3D printing to not only test their materials through merciless, standardized test procedures — but also actually run those tests with 3D printed specimen.

Nanovia happens to do this, and there’s a whole lot of information on how these tests are conducted in their paper on the impact of carbon fiber in 3D printed materials. The paper suggests a 35 % increase of the tensile modulus over non-infused filaments, and either way, it’s good to know the properties of the material once it’s out of the nozzle.

However, since most filament manufacturers simply copy the test values for their technical data sheets from their resin suppliers (which, of course, use injection molded specimen), it’s hard to independently compare these values to a stereotypical, non-infused filament.

Breaking stuff is the ISO 527 of the common man, and so I printed a few test blocks just to break them into half. The results are shown below, and at least give you an idea of how the fiber content modifies the material’s behavior under stress. The little testing bricks were printed at 70 mm/s and 270 °C and bent to a 90° angle by meticulous professionals using a lab-grade vice and a standardized lot of force.

While regular ABS clearly shows how the fracture rips the joints between the tool-paths apart, the fractures in the infused materials happen distinctively more uniform, indicating proper bonding between the laid down strands of material. Also, a large stress whitening zone suggests that the composite materials distributes stress more effectively across the entire block. Below you can see the cross-section of the fracture. I’ll be happy to hear your additions to these conclusions in the comments — and feel free to debunk them entirely.

Conclusion

I like these filaments. Both materials come with a great, compromise-free print quality and produce tough parts even at the upper-end of their print speed recommendation: blazing 70 mm/s. Since I only had about 20 grams of each filament from the sample pack, I could not experiment much and had to rely entirely on the printing parameters from the data sheet. I was not disappointed and the demo prints shown in this article came out great in the first instance. A complete data sheet with well-tuned printing parameters and actual, 3D-printing-relevant mechanical properties is certainly something I’d wish to see with more filaments out there.

In terms of resilience, neither material’s datasheet blows your socks off with unrealistic values from injection-molded test specimens, but they are exceptionally tough. A major benefit of the fiber content is the composites’ reduced tendency to warp, allowing you to print larger structures with higher shape fidelity. This is something to consider, if you — like me — love working with ABS, but sometimes run into applications where even the slightest warping is intolerable. Or if you — like the Oak Ridge National Laboratory — set out to print the world’s largest solid 3D printed object to date, which is also printed from carbon-fiber-infused ABS. I’d put this material into the category of productive work: it’s a tough material that simply delivers great results at a reasonable throughput.

I hope you enjoyed taking a look at another special filament. There are a whole lot more in the box, like PTFE, glass-fiber infused filaments and others, so stay tuned for my further 3D printing adventures. Got a melting-hot tip on a great filament or experiences with your favorite (or most hated) filament to share? Put them right there in the comments!

Test conditions

Printer: Prusa i3 Einstein Rework (Proosha IIIo , photo) Hotend: E3Dv6 w/ 0.4 mm hardened steel nozzle, E3D PT100 thermocouple kit, narrowly ducted, axial nozzle fan, super-power-bestowing jolly wrencher fan guard Drive System: GT-2 belt drive with 20T pulleys for XY, M5 threaded rod for Z w/ cardan coupling, 0.9° 1.7 A Wantai stepper motors, DRV8825 Stepper Drivers in 8x microstepping mode for XY, IGUS RJ4JP-01-08 dry lubrication bushings on XY, LM8LUU linear bearings for Z Electronics: Ramps 1.4, Arduino Mega 2560, 12 V / 500 W ATX power supply Build plate: Makertum MK1 500W AC heated bed, Vishay NTCLE203E3 thermistor, PEI printing plate clamped on top, capacitive distance switch for auto bed leveling Firmware: Marlin-RC7