Beyond the simple world of basic PLA filaments there is a whole wild world of additives that can change this humble material for better or worse. The most common additives here are primarily to add color, but other additives seek to specifically improve certain properties of PLA. For example Bambu Lab’s new PLA Tough+ filament series that [Dr. Igor Gaspar] over at the My Tech Fun YouTube channel had over for reviewing purposes.
According to Bambu Lab’s claims for the filament, it’s supposed to have ‘up to’ double the layer adhesion strength as their basic PLA, while being much more robust when it comes to flexing and ‘taking a beating’. Yet as [Igor] goes through his battery of tests – comparing PLA Tough+ against the basic PLA – the supposedly tough filament is significantly worse in every count. That sad streak lasts until the impact tests, which is where we see a curious set of results – as shown above – as well as [Igor]’s new set of impact testing toys being put through their paces.
Of note is that although the Tough+ variants tested are consistently less brittle than their basic PLA counterparts, the Silver basic PLA variant makes an unexpectedly impressive showing. This is a good example of how color additives can have very positive impacts on a basic polymer like PLA, as well as a good indication that at least Bambu Lab’s Basic PLA in its Silver variant is basically better than Tough+ filaments. Not only does it not require higher printing temperatures, it also doesn’t produce more smelly VOCs, while being overall more robust.
I don’t have any hard data, nor do I know the original company that made it, but Bambu’s original Tough PLA was awesome, and still to this day the best filament Ive run through my Kickstarter X1. Their PETG HF is awesome and my current go to filament for most things. With bulk pricing in the US, the PETG HF is surprisingly affordable. My Voron 2.4 especially loves it.
Interesting, silver PLA is strong. I have noticed white PLA being weak. I would like to see a study regarding color side-effects.
CNC Kitchen has a study about how color affects strength from January 2023. Pigments can definitely affect properties. I find gray filaments tend to be consistently strong, and I’ve had issues with white as well.
As much as I love these empiracle tests, I’ve found that they don’t always match reality. For example there are lots of tests that consistently show petg as being generally inferior to PLA and “not as tough as it seems”. And yet I’ve made a lot of mechanical 3D prints over the years, and the PETG prints consistently last MUCH longer than PLA before breaking. My friends have come to the same conclusion. Maybe it has something to do with aging and UV degradation that these YouTube tests don’t capture, but whatever it is, the fact is that these charts don’t seem to match reality in a lot of cases.
PLA hydrolyzes from ambient humidity and rapidly becomes brittle unless it’s kept very dry. I’ve had old PLA filament snap/crumble just by unrolling it from the spool.
Esun make a nice PLA with the ST suffix. Similar to the new Bambu stuff, it is significantly weaker in tension but you can hammer on a print without it cracking.
Sorry, this was meant to be a general comment, not a reply.
The tests are good for showing the material properties when new, but as you’ve said, that doesn’t necessarily translate to how they perform in a particular print or over time.
PETG might rate lower than PLA in absolute terms, but it survives far better in elevated temperatures and after extended exposure to humidity – both things that have caused me grief with PLA prints. The big drawback to PETG was simply that it is harder to print than PLA, but that practically vanished once I moved to one of the current crop of modern high-speed printers. PETG just seems to hate being printed slowly.
In these tests the often seem to skip drying filament too, unless it’s stringing really bad.
They should be drying every filament to manufacturer specifications, then running temperature, flow, and pressure advance calibrations on the dried filament before printing.
It would be the only way to be able to consistently compare the actual properties of the printed filament.
I think toughness might be more important than it gets credit for.
“Real” parts have stress risers, especially 3d printed ones. They can be minimized in design but i dont see people do this often for 3d printed parts and the layer lines will always be a stress riser. Even if the part never sees a real impact, toughness is important when it sees stress, some areas must deform plasticly.
The other thing ive noticed with pet-g is you dont just get really good layer adhesion when things are going well, you get good layer adhesion pertty much everywhere, everytime. Combined with its really high toughness, this makes it a great material for strength critical FDM without crossing into higher temperature materials. Its only downsides are stiffness and operating temperature. I wouldnt mind playing around with fiber reinforced pet-g if i had a need for something a bit stiffer.
Petg-cf is one of my favorite filaments. It’s so easy to print with and the added strength plus PETGs natural impact resistance makes for a very nicely balanced part.
yeah that’s exactly my thought…i’ve used 3 PLA+ filaments…PolyMaker PolyMax smelled bad and warped (abandoned the good parts of PLA), but FormFutura EasyFil and MatterHackers Tough PLA each pleased me at first. but it doesn’t matter, because after about a year of ambient indoor humidity, it’s brittle garbage. if i make it thick and don’t put any stress at all on it, i can get a decade out of it…but if i test it then even that is very obviously degraded to the edge of failure.
i don’t want a marginal increase in impact durability on the day it was printed, i want a 10-fold or 100-fold increase in duarbility after a year. it seems like people are still trying to optimize things that simply don’t matter. for now, i use PETG.
In my opinion PLA is absolute trash no matter what additives. If you leave the spool in open air for 2 years it will crumble like dry spaghetti. They say you should dry it before printing when that happens. But guess what. This exact thing will affect the finished print as well… Just save yourself headache and don’t use PLA for anything that needs more structural strength than plaster of paris… I really like how PLA looks, and how easy it is to print. But that’s about it…
It’s good for patterns and molds though, especially if they’re only getting used once or twice. I’d rather throw away PLA than something that’ll never decompose.
PLA doesn’t really decompose either. It CAN if you put it in industrial composters that he got enough to break it down.
But industrial composters don’t allow it because it takes significantly longer than other, natural materials and time = money.
The nice thing about PLA is it’s plant based and renewable. But it doesn’t break down in landfills anymore than ABS does.
I guess not all PLA is equal. I’ve got PLA parts printed from up to 9 years ago still fine (indoors only, of course).
No thermal tests? I don’t care how tough it is, if it melts in a hot car, I’m not going to use it.
That is specifically why I moved to Petg for any project that has a chance of being under any load in elevated temperatures, I had a thermostat battery die and lost several panels of a printed wall system
I hear you. I once took some pla prototypes to a client for functional tests in summer. Stopped along the way, by the time I grabbed them from the car they were too warped to be functional.
THIS!
I can’t understand why a plastic that melts in a car or even just outside on a hot, sunny day is so popular.