Is PLA durable for outside use ?
I want to design a bird feeder and print in PLA, would it withstand 30c temperatures ? Or below freezing ?
Here ya go! I remembered this nice article of someone printing a slug trap out of PLA and they go over how it’s faired outside for a year: http://www.protoparadigm.com/blog/2013/06/weathering-of-3d-printed-pla-objects/
@John_Ridley
Not watertight? Seems like most of these prints would be. I don’t have my printer yet, but I would think any leaks would be due to a problem with layer adhesion.
@Carlton_Dodd even with the best prints the result is still very porous and will suck water inside due to osmosis. Paint of varnish can help waterproof it.
Great link @ThantiK … my first thought was whether they’d deteriorate in UV. After reading this, I googled it and found:
“UV resistance. Unlike other synthetic fibers, PLA does not absorb light in
the visible region of the spectrum; this leads to very low strength loss
compared to petroleum-based fibers when exposed to ultraviolet light.”
[PDF link] http://jimluntllc.com/pdfs/polylactic_fibers.pdf
Out of curiosity, I looked up ABS and UV and found this:
“The carbon-carbon double bond (C=C), which is responsible for the
elastomeric behavior of the rubber, is extremely sensitive to UV energy. This energy causes oxidation and crosslinking that modifies the materials rubbery behavior to one of a more brittle nature. Degradation from weathering starts at the surface and results in a rapid loss of mechanical properties such as ultimate elongation, toughness, and impact strength.
To avoid degradation, ABS is frequently protected by the inclusion of carbon black in the formulation. The addition of sufficient carbon black can make these polymers very weather resistant, as evidenced by the good field history of black ABS (acrylonitrilebutadiene-styrene) pipe. Carbon black is the most common UV stabilizer used for extended outdoor applications.”
[PDF link] http://plasticpipe.org/pdf/tr-18_weatherability_thermo_pipe_systems.pdf
Wonder about non-black ABS… or even the black ABS that’s typically used for 3D printer filament… if it contains the carbon black or if it’s just black dye?
It seems that PLA, despite being “biodegradable”, holds up fairly well to moisture, although… as mentioned, if any gets inside and gets frozen, that could cause damage (just like freezing pipes). Both PLA and ABS seem fairly moisture resistant otherwise, so UV seemed the next obvious outdoor hazard.
@John_Ridley I’ve found that increasing the extrusion width for solid infill under slic3r’s advance settings can ensure that you get a watertight fill. I currently use 120% extrusion width and there’s a teeny bit of overfill, but my prints are watertight.
Possibly… guess it depends on what they’re made out of.
I read a post about someone who left his parts out for more than a year. Aside from some decoloring it held up perfect.
I suggest you don’t use black pla. Black absorbs heat when the sun shines on it and that will make you model deform.
The PDF I linked says that PLA doesn’t absorb “visible” light (although it seems to be indicating that this is the reason it’s UV resistant?) so not sure the color is much of an issue for PLA. Black will cause it to heat up more, but unless it’s in a car or somewhere that gets extra hot, the ~100F. Looks like you might not have many issues until you hit around 140F or so maybe?
The ABS is the one that said sometimes they mix “carbon black” into it to help add some UV resistance.
I’ve had a black ABS parts sitting in the full sun for the last two years (and winters) and they still look and feel like new. I believe the filament contained enough carbon black to keep UV away (since it’s the cheapest black pigment).
BTW… for what it’s worth… I get the impression that the concerns over porousness wasn’t about leaking, but more about liquid permeating the plastic and, in the example of freezing temperatures, expanding and damaging the object, but also if you had a material that was say susceptible to dissolving in alcohol, but maybe it took a really long time, that if you used it as a shot glass, maybe it would degrade quicker over time if some of the alcohol got into the pores in the plastic. Again, not a leaking issue, but just issues with liquids permeating the material and causing issues in some way.