PVDF: The Specialized Filament For Chemical And Moisture Resistance

August 28, 2025 by Maya Posch 18 Comments

There’s a dizzying number of specialist 3D printing materials out there, some of which do try to offer an alternative to PLA, PA6, ABS, etc., while others are happy to stay in their own niche. Polyvinylidene fluoride (PVDF) is one of these materials, with the [My Tech Fun] YouTube channel recently getting sent a spool of PVDF for testing, which retails for a cool $188.

Some of the build plate carnage observed after printing with PVDF. (Credit: My Tech Fun, YouTube)

Reading the specifications and datasheet for the filament over at the manufacturer’s website it’s pretty clear what the selling points are for this material are. For the chemists in the audience the addition of fluoride is probably a dead giveaway, as fluoride bonds in a material tend to be very stable. Hence PVDF ((C₂H₂F₂)_n) sees use in applications where strong resistance to aggressive chemicals as well as hydrolysis are a requirement, not to mention no hygroscopic inclinations, somewhat like PTFE and kin.

In the video’s mechanical testing it was therefore unsurprising that other than abrasion resistance it’s overall worse and more brittle than PA6 (nylon). It was also found that printing this material with two different FDM printers with the required bed temperature of 110°C was somewhat rough, with some warping and a wrecked engineering build plate in the Bambu Lab printer due to what appears to be an interaction with the usual glue stick material. Once you get the print settings dialed in it’s not too complicated, but it’s definitely not a filament for casual use.

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Should You Try Printing With Polypropylene?

August 18, 2025 by Tyler August 11 Comments

Of all the plastics that surround us on the daily, the one we hear least about in the 3D printing world is probably polypropylene (PP). Given that this tough, slightly flexible thermoplastic has characteristics you might want for your prints, the question is: why? [Lost in Tech] is not answering that question in a recent video; instead he’s showing us what we’re missing out on with a review of the material.

A look at the Material Safety Data Sheet and available material has [Lost in Tech] suggesting it won’t be (much) more toxic for you than PLA, but you still wouldn’t want to huff the fumes. The biggest issue printing PP is getting it to stick — glass beds and PEI are not your friend, but polypropylene tape is easy to find and makes a fine print surface. He reviews a few other options, but it looks like plain old tape is still your best bet if you can’t get a hold of a Prusa PP bed. The other big issue is shrinkage, but that’s hardly unique to PP and can be accounted for in the model.

Just because it can be used, that doesn’t mean it should be. [Lost in Tech] does make a good case for why you might want to use PP — for one thing, it doesn’t string much, in part because it’s not hygroscopic. That makes it great for those of us in humid climes who don’t want to always faff around with dry boxes, but also wonderful for parts that will be in touch with water. Polypropylene also has great chemical resistance for even scarier chemicals than dihydrogen monoxide. The “killer app” though, at least as far as [Lost in Tech] is concerned, is to use polypropylene with compliant mechanisms: it’s incredibly resilient to bending, and doesn’t fatigue easily. You might even call it a “flexible” filament, but unlike with TPU, you get a nice hard plastic to go with that flexibility.

If you’re interested in this somewhat-forgotten filament, we featured a “getting started” guide last year. You can even make your own polypropylene filament using non-medical “COVID” masks, but do be sure to wash them first. What do you think? Is it time to give PP another chance, or has the 3D printing world moved on? Continue reading “Should You Try Printing With Polypropylene?” →

A filament extruder is shown on a workbench. On the front is a knob and the display of a PID controller. A black geared spool is mounted on the top of the extruder, and on the right, a clear plastic bottle is positioned over a metal rod.

Turning Waste Plastic Into Spools Of Filament

August 1, 2025 by Aaron Beckendorf 28 Comments

Despite being a readily-available source of useful plastic, massive numbers of disposable bottles go to waste every day. To remedy this problem (or take advantage of this situation, depending on your perspective) [Igor Tylman] created the PETmachine, an extruder to make 3D printer filament from PET plastic bottles.

The design of the extruder is fairly standard for such machines: a knife mounted to the frame slices the bottle into one long strip, which feeds through a heated extruder onto a spool which pulls the plastic strand through the system. This design stands out, though, in its documentation and ease of assembly. The detailed assembly guides, diagrams, and the lack of crimped or soldered connections all make it evident that this was designed to be built in a classroom. The filament produced is of respectable quality: 1.75 mm diameter, usually within a tolerance of 0.05 mm, as long as the extruder’s temperature and the spool’s speed were properly calibrated. However, printing with the filament does require an all-metal hotend capable of 270 ℃, and a dual-drive extruder is recommended.

One issue with the extruder is that each bottle only produces a short strand of filament, which isn’t sufficient for printing larger objects. Thus, [Igor] also created a filament welder and a spooling machine. The welder uses an induction coil to heat up a steel tube, inside of which the ends of the filament sections are pressed together to create a bond. The filament winder, for its part, can wind with adjustable speed and tension, and uses a moving guide to distribute the filament evenly across the spool, avoiding tangles.

If you’re interested in this kind of extruder, we’ve covered a number of similar designs in the past. The variety of filament welders, however, is a bit more limited.

Thanks to [RomanMal] for the tip!

Nylon-Like TPU Filament: Testing CC3D’s 72D TPU

July 22, 2025 by Maya Posch 8 Comments

Another entry in the world of interesting FDM filaments comes courtesy of CC3D with their 72D TPU filament, with [Dr. Igor Gaspar] putting it to the test in his recent video. The use of the Shore hardness D scale rather than the typical A scale is a strong indication that something is different about this TPU. The manufacturer claims ‘nylon-like’ performance, which should give this TPU filament much more hardness and resistance to abrasion. The questions are whether this filament lives up to these promises, and whether it is at all fun to print with.

The CC3D 72D TPU filament used to print a bicycle's handlebar. (Credit: My Tech Fun, YouTube) — The CC3D 72D TPU filament used to print a bicycle’s handlebar grips. (Credit: My Tech Fun, YouTube)

TPU is of course highly hydrophilic, so keeping the filament away from moisture is essential. Printing temperature is listed on the spool as 225 – 245°C, and the filament is very bendable but not stretchable. For the testing a Bambu Lab X-1 Carbon was used, with the filament directly loaded from the filament dryer. After an overnight print session resulted in spaghetti due to warping, it was found that generic TPU settings at 240ºC with some more nylon-specific tweaks seemed to give the best results, with other FDM printers also working well that way.

The comparison was against Bambu Lab’s 68D TPU for AMS. Most noticeable is that the 72D TPU easily suffers permanent deformation, while being much more wear resistant than e.g. PLA. That said, it does indeed seem to perform more like polyamide filaments, making it perhaps an interesting alternative there. Although there’s some confusion about whether this TPU filament has polyamide added to it, it seems to be pure TPU, just like the Bambu Lab 68D filament.

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Elegoo Rapid PETG Vs PETG Pro: Same Price, Similar Specs, Which To Buy?

July 19, 2025 by Maya Posch 16 Comments

Even within a single type of FDM filament there is an overwhelming amount of choice. Take for example Elegoo’s PETG filament offerings, which include such varieties like ‘Pro’ and ‘Rapid’. Both cost the same, but is there a reason to prefer one over the other, perhaps even just for specific applications? To test this, [Dr. Igor Gaspar] over at the My Tech Fun YouTube channel bought some spools of these two filaments and subjected both to a series of tests.

Obviously, the Rapid filament is rated for higher extrusion speeds – <270 vs <600 mm/s – while the website claims a higher required nozzle temperature that confusingly does not match those listed on the spool. There are quite a few differences in the listed specifications, including the physical and mechanical properties, which make it hard to draw any immediate conclusions. Could you perhaps just use Rapid PETG and forget about the Pro version?

Test objects were printed with a Bambu Lab P1P with an AMS unit. After calibrating the ideal temperature for each filament, a tensile break test gave a win to the Rapid PETG, followed by a layer adhesion test win. This pattern continued across further tests, with Rapid PETG either matching or beating the Pro PETG.

There are only two advantages of the Pro version that can be seen here, which are less moisture sensitivity and stringing risk, and you of course get the luxury cardboard spool with the closed edges. Whether that’s enough to make you go ‘Pro’ remains to be seen, of course.

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Introducing PooLA Filament: Grass Fiber-Reinforced PLA

July 14, 2025 by Maya Posch 25 Comments

We’re probably all familiar with adding wood dust, hemp and carbon fibers to PLA filament, but there are so many other fillers one could add. During the completely unrelated recent heatwave in Germany, [Stefan] from CNCKitchen decided to give a new type of biodegradable filler type a shot by scooping some freshly dried cow patties off the very picturesque grazing fields near his place. In the resulting video a number of questions are answered about this ‘PooLA’ that nobody was asking, such as whether it makes for a good filler, and whether it smells bad while printing.

Perhaps unsurprisingly to those who have spent any amount of time around large herbivores like cows, cow dung doesn’t smell bad since it’s mostly composed of the grass fibers that are left over after the cow’s multiple stomachs and repeated chewing have done their thing. As [Stefan] and his colleagues thus found out was that printing with PooLA smells like printing with grass.

As for the practical benefits of PooLA, it adds a nice coloring, but like other ‘reinforced’ PLA filaments seems to trade flexibility for stiffness, so that at ratios of cow dung powder between 5 to 20% added to the PLA powder the test parts would break faster. Creating the filament was also a bit of a chore, for reasons that [Stefan] still has to figure out.

That said, aside from the technically unneeded bacterial corpses and other detritus in cow patties, using grass fibers in FDM filament isn’t a crazy idea, and might fit right in there with other fibers.

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Turning Up The Heat On HT-PLA’s Marketing

June 9, 2025 by Tyler August 28 Comments

PLA is probably the most-printed filament on the market these days, and is there any wonder? It’s cheap, it’s easy, and it doesn’t poison you (as quickly as its competitors, anyway). What it doesn’t do very well is take the heat. Polymaker’s new HT-PLA formulation promises to solve that, and [My Tech Fun] put those claims to the test in a recent video.

Polymaker claims its HT-PLA is heat-stable up-to 150 C, but still prints as easily as standard PLA at up to 300 mm/s. By “heat stable” they mean able to maintain dimensions and form at that temperature when not under any load, save perhaps its own weight. If you need high-temp mechanical properties, they also offer a glass-fiber infused HT-PLA-GF that they claim is heat resistant up to 110 C (that is, able to withstand load at that temperature) which is hard to sneeze at, considering you you could print it on a stock Ender so long as you tossed a hardened nozzle on it.

Now it’s not a free lunch: to get the very best results, you do need to anneal the parts, which can introduce shrinkage and warping in HT-PLA, but that’s where HT-PLA-GF shines. If you want to see the results of the tests you can jump to 19:27 in the video, but the short version is that this is mechanically like PLA and can take the heat.

The verdict? If you like printing PLA and want to shove something in a hot car, you might want to try HT-PLA. Otherwise, it’s just like PLA. It prints like PLA, it looks like PLA, and when cold it behaves mechanically like PLA, which we suppose was rather what Polymaker was going for. There is no word yet on whether the additives that make it high-temp increase off-gassing or toxicity but since this stuff prints like PLA and can stand a little airflow, it should be easy to ventilate, which might make for fewer trade-offs when building an enclosure.

What do you think, will you be trying HT-PLA anytime soon? Let us know in the comments.

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