New to 3D printing: How do I find out how likely a filament is to deform under constant load/creep?

[shadow pike]

I'm brand new to 3d printing, just got my first printer (Sovol SV07+) yesterday, now I'm doing some calibrations and I'm figuring out what I need for some of the first prints I make. A lot of those will require a constant sustained load, which I've heard/read that PLA can't really handle but I haven't seen anything about other common types of filament. None of the characteristics on Polymaker's materials comparison tool (https://app.polymaker.com/) seem to address this either, even though it seems like this should be a common concern.

As for what I'm looking for right now, it's all room temperature stuff like shelf brackets, feet for a desk I made from a cutting board countertop, a wider bath towel hook, and some other things of that nature. I would prefer to learn how to find out the information myself, but if there's a go to material that everyone "just knows" to use for these sorts of items, that would be helpful information as well. I do have a basic tent enclosure on order, so I could probably manage some of the easier "enclosure recommended" materials like ASA if needed.

[glad hearth]

PLA will deform under stress even at room temperature.
All plastic will to some degree but PLA is way way worse.

PETG is better, ABS is even better.

Nylon is maybe between PLA and PETG, I'm not sure.

See what you can find for creep in sciencedirect or Google scholar ...

https://3dprinting.stackexchange.com/questions/11657/which-material-creeps-plastic-deformation-the-least-or-nothing-at-all-unde

[shadow pike]

Okay, I've done a good bit of searching over the last few days. It looks like there are some pretty standard methods to test for creep, but none of the details like weights, pressures, or profiles are standardized so no two values in different papers can be compared. Everything I've found has tested one or two filaments, usually under various other factors related to print settings, but I haven't found anything that looks at a range of common filaments.

That said, https://www.mdpi.com/1996-1944/16/13/4610 Section 3.2 was incredibly helpful

It seems like anything referred to as "engineering" materials are not likely to creep too much at loads/pressures you would normally put on plastic parts and it's highly correlated with filaments described as "durable".

So if you see a filament described as durable or a good engineering filament, you can be pretty sure it won't creep too much as long as you're well below its heat, load/pressure limits, and not exposed to any chemicals that will degrade it. All factors will increase creep and not in a linear way, see https://www.sciencedirect.com/science/article/pii/S2214860422004183 for a good overview of the how and why.

It would be awesome for Polymaker to add a creep measurement to their material comparison tool which is internally consistent even if there's no ISO standard test. Maybe that would finally be the impetus to create a standard test. 🙏

[glad hearth]

Buy the ISO 75 specifications, that's where the shapes, weights, procedures are defined.

[mighty plover]

Some YouTubers compare many filaments using the same procedure. It’s not paper-worthy science, but pretty reliable

Here’s one I watched about the common materials

https://youtu.be/88pk2cNOeGE?si=KmSMyee0Y_-IOnmM

Also, for desk feet, TPU would be the best due to the fact that it’s great in compression and is a little bit grippy and won’t scratch up the floor

[shadow pike]

Thanks, this is exactly the sort of thing I was looking for. It looks like I might be able to use PLA for some of my lighter room temperature loads (e.g. towel rack), which is counter to many people's advice that PETG would be much better. ASA does seem to be the clear winner there for anything that needs to handle a decent load though, which is about what I expected.

This one was also pretty helpful https://www.youtube.com/watch?v=QdAKd_YbsjI