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Comment by biggerfisch | Hacker News Reader

> but the only affordable printing materials are cheap ABS plastics

Not very true at all. You can get PLA for $20/1kg or less. Even resin for SLA printers is often possible to find for affordable prices, especially considering that you can sometimes use less material without the need for infill.

I'm really not even sold on the idea that so many people "need" metal printers. Seems like most people would be way better off with the incredibly cheaper plastic options.

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Isn't PLA less structurally sound than ABS? I thought the reason it was used over ABS was that it could be formed at a lower temperature.

Yes, PLA is somewhat weaker, but still more than strong enough for most desktop printing applications. It's also much less toxic to print with than ABS.

Can we get a citation for the toxicity of ABS? My Google-fu is failing me as I can only find articles that say the fumes can cause minor irritation when inhaled or in contact with the eyes.

"The higher temperature ABS-based printers had total UFP emission rates nearly an order of magnitude higher than the lower temperature PLA-based printers (1.8-2.0 10^11/min compared to 1.9-2.0 10^10/min)."

"Primary gas-phase products of ABS thermal decomposition at very high temperatures have been shown to include carbon monoxide and hydrogen cyanide, as well as a variety of volatile organics (Rutkowski and Levin, 1986). Exposure to thermal decomposition products from ABS has also been shown to have toxic effects in both rats (Zitting and Savolainen, 1980) and mice (Schaper et al., 1994)."

from http://ac.els-cdn.com/S1352231013005086/1-s2.0-S135223101300...

Doesn't it put off styrene gas?

Doesn't it also seriously degrade over time in UV light?

Only minimal delamination, solvable by increasing print temperature. For SLA resin prints though UV exposure is a big problem.

Perhaps that's what I was thinking of.

PLA is also susceptible to heat. Leave a PLA model out in your car with the windows rolled up in the summertime (especially here in Arizona where you can easily cook a meal in your car!) - and you'll come back to a model in not-so-good shape (it won't melt, but it will deform and sag).

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