white ABS discoloration under LED light

[leelauer]

I've had a lot of luck using Hatchbox PLA and ABS and tried their white ABS to use as a diffusion layer in a light box. When printed the color looks like a very nice bright white but when LEDs (also white) shine through it the ABS turns yellow. Anyone else expreience this or know of a brand of white ABS that doesn't discolor?

[fred_dot_u]

The change to non-white coloration is an indication that the "white" LEDs are not a true white color temperature. If you are seeing white under sunlight, you'll want to find a more daylight color temperature (>6500K) as a source illumination.

[leelauer]

The change to non-white coloration is an indication that the "white" LEDs are not a true white color temperature. If you are seeing white under sunlight, you'll want to find a more daylight color temperature (>6500K) as a source illumination.

These LEDs are 6500k and when used with acrylic white panels, they shine white as expected. I was hoping to print the white parts as that's far easier and cheaper than cutting panels of acrylic. Also, the thicker the printed ABS, the more yellow it gets.

[fred_dot_u]

That's unfortunate. I have a half dozen different brands and materials of white, PLA, ABS, HIPS (and ASA in a sealed box). Of the ones I just checked, the unknown brand stuff appeared to have a yellow cast to it. The HIPS is probably the whitest, only outdone by white NinjaFlex. My spools of MatterHackers Build PLA are a toss-up, uncertain how those would look, but the MatterHackers ABS is clean white. I think it's a gamble, unless you can get a sample sent to you for testing.

[leelauer]

Thanks, I'll have to check out that filament brand.

[Gambo]

I think you provided the answer to your own problem. Filament is white because it has mixed with it a white pigment normally titanium dioxide this very white but opaque so the filament looks white by reflected light but being opaque the pigment blocks transmitted light so the only light that gets through is coloured be the filaments polymer natural colour. If you want to make a light diffuser you will need to use a transparent filament.

[leelauer]

I think you provided the answer to your own problem. Filament is white because it has mixed with it a white pigment normally titanium dioxide this very white but opaque so the filament looks white by reflected light but being opaque the pigment blocks transmitted light so the only light that gets through is coloured be the filaments polymer natural colour. If you want to make a light diffuser you will need to use a transparent filament.

Yeah that makes total sense now that you mention it.