Hello all. I live in the desert southwest of the US and print a lot of outdoor objects, usually sticking to ASA. There’s a ton of testing and info on the mechanical properties of filaments out there, but it seems like the manufacturers are sort of ‘trust me bro’ when it comes to UV resistance of their products. Anecdotally, I’ve had a hunch that some brands of filaments adulterate their ASA with other materials that reduces UV resistance, but it’s more a feeling versus any proof. So, as summer is heating up here in ■■■■ (107F, 41.7C yesterday, ugh) I decided to print up some test swatches of all the ASA filaments I have on hand (and a few others) and put them outside to see which filaments hold up the best. I’m posting this thread to provide periodic updates and at least share something positive from the misery I’m enduring for the next few months.
So, I printed up 75mmx25mmx5mm swatches of every brand, color, and variant of ASA I had in my stockpile. My wife would have killed me if I bought any more filament so there are a few I didn’t have that I would have loved to test, but still, it’s a pretty comprehensive test. I also included a couple PLA and PETG swatches for comparison, and also applied Siraya Tech’s Aegis Matte and Clear coating to a Bambu Lab black ASA swatch just for the heck of it. I know they’re not meant to provide UV protection, but they’ve been sitting on my workbench and I figured I should do something with them.
I screwed them all down on a piece of scrap plywood (with a white paper coating that probably won’t last) and hung them out in my yard on a south facing chain link fence that gets pretty constant all day sun exposure during the summer. So here’s the initial list of filaments and the pictures of them on day one when I hung them up today. I’ll be updating as I see any interesting changes or results all summer long.
FILAMENT LIST:
Sunlu ASA Black
Polymaker ASA Olive Brown
Fiberon ASA-CF08 Dark Grey
Fiberon ASA-CF08 Desert Sand
Siraya Tech ASA-GF Black
Bambu Labs ASA Black
Bambu Labs ASA White
Bambu Labs ASA Grey
Bambu Labs ASA Red
Siraya Tech ASA-GF White
Bambu Labs ASA Black with Siraya Tech Aegis Clear Coating
Bambu Labs ASA Black with Siraya Tech Aegis Matte Coating
That’s a great idea. Maybe another experiment with them under tension during the test is in order. The only thing that gives me pause is I’m not sure how to go about implementing it in an accurate way without some testing equipment I don’t currently have. I was thinking of doing some destructive testing at the end of the experiment but haven’t put a lot of thought into it yet and it may have the same challenges in terms of accuracy. But I’m not an engineer so if anyone has any suggestions or ideas on how to do any of these sort of things (a) cheaply and (b) easily please feel free to chime in. I’d love to give it a shot. I’m not really qualified to do anything too technically/scientifically rigorous but maybe someone like mytechfun (one of my favorite youtubers) would take it on too.
Hmm, I guess in my mind the reason I’m interested in UV resistance is primarily because of an underlying assumption I have that poor UV resistance will lead to earlier breakage…and that I can visually tell by appearance if something is experiencing UV degradation. I think the first part is probably accurate, but thinking about it, the second part of the assumption (that one can identify uv degradation visually) is probably only partially true at best. I suppose that’s why I didn’t look at your idea as a separate experiment–mainly because my main interest lies in functional part strength/resistance to UV degradation. So thinking it through more, the OCD part of me now really wants to do some version of your idea–since it’s basically exposed a flaw in my thinking! I’m trying to remind myself that the perfect is the enemy of the good, and that to some degree UV degradation can be seen visually…but still…I can’t shake wanting more data! Dang you! lol
To be better able to isolate UV effects only, you could place identical samples on the back of the panel and angle it so one side is always in the shade.
In that manner, you always have reference samples you can compare with.
&
PS: Or, since you are interested in the material degradation, you could skip the swatch printing step and just use strips of filament. That would make it easier to test for strength degradation/creep although I’d expect that to be more affected by heat than by UV.
If UV resistance is the main goal of this test, and not warping due to heat, I think you will get bored of this though. I bet you won’t see any UV damage to these swatches for at least 5 years, maybe 10. ASA is really good at keeping it’s integrity in the sun.
But they could warp though, that would be because of the heat in your case. Desert sun, on a windless day would surely heat the darker ones to insane temps and warp them.
& 