What material to use?

[DGTalic 0]

Hi. I need to create and print an object that will be in water for very long periods of time. Residual waters. It is basically a mesh that holds together a sponge that acts as a water filter. Any suggestions on what material to use? Would PLA work just fine? See image attached.

Many thanks in advance.

[AreDigg 8]

I would avoid PLA as it is biodegradable. Maybe it is ok in distilled water. The best are all oil based plastics which can last for decades or 100-1000 years in water.

But all plastics do absorb water to a degree, but in your case it should not matter much. I would avoid nylon. HDPE/PET are commonly used in water storage containers, but ABS should work just fine for your purpose.

[geert_2 557]

PLA does get dull and brittle. Out of curiosity, I tried a filter in the waste water syphon of my lab. It took a year or so, and it still functioned, but you could clearly see the dullness and color change (more pale, white-ish). So there is some degradation going on.

I haven't tried any other materials, but I would guess that PET or its derivatives are worth a try. They are used for lots of drink bottles anyway.

If you select a water-clear filament, you can easier see what is going on inside the material (e.g. color changes).

[DGTalic 0]

Many thanks to both! Greatly appreciated.