1

_​_​I was thinking about ordering a coffee mug model in the ProtoPasta stainless steel filament but have one question, is it safe to drink hot coffee out of? I know this extrudes at about twice the temperature the coffee is but is it safe? I have printed a ABS mug that I have used for the last 11 months, well I’m still alive, and the mug still seems to not have a problem.

Can someone tell me if I can use this material or not?

3 Likes
2

Unfortunately, it isn’t. While it has a stainless steel filler, the base material is PLA, which has a glass transition of only 65C-70C (Fresh boiling coffee would be 100C). ABS works for a mug material since its glass transition can be from 80C to 125C, and generally 3D printing grade ABS is around 110C.

While it would most likely be safe, seeing as steel isn’t toxic in low quantities and PLA especially isn’t toxic, the mug would just get soft and rubbery and eventually deform to the point where it’s no longer a mug.

1 Like
3

Thank you!!

4

You can’t use that. PLA (which is the base material for proto pasta) gets soft at 60C so it would deform and it might release toxic particles. ABS gets soft at 100-120c so that’s fine for coffee mugs. The temperature spot I’m talking about is called glass transition temperature and it’s usually

2 Likes
5

@MB3D @karlzhoo314

I wouldn’t use a PLA based filament for food stuffs that’s not had FDA approval. I researched it a bit on the internet and came across a post which stated that the 3D printed mug used in the bathroom for the mouth rinse had started growing mould and was thrown out, after a few months.

PLA’s surface is porous with tiny holes so a good place for bacterial growth and it’s also hygroscopic.

Even if your printer is cleaned, what is the nozzle like after pushing ABS (can be toxic) though it.

The 3D chocolate printers used ceramic nozzles, suitable for and regarding food use.

There is also Purement filament http://www.shop.3dfilaprint.com/purement---anti-microbial-filament-137-c.asp

Which is I would say the best choice for printing household items for kitchen and bathroom but the jury is still out (is it safe?) on printing those items with a home based printer.

Tea is brewed at 100 degrees c. Coffee at about 80 degrees That temperature puts then both in range of the transition temp that would be like holding water in tissue, it wouldn’t pour out it would drip and burn the hand holding it.

Once as test, I put boiling water in a PLA cup, it didn’t leek to start with but then started to drip, just proves designing and making products using 3D printers is about using the right materials and processes for it’s intended use

6

Colorfabb XT is FDA approved (food safe) and has a glass transition temperature of 70-80c so it might just be within the material capabilities. I don’t know for sure, but I could think of PMMA or PC (both with Tg>120c) can be food safe. Most 3D printer nozzles are made from brass which means that they contain lead (to a very low amount). The brass nozzle will wear down to a very low percentage during printing so it can happen, that lead particles get into the 3d print and from there it’s just a short way into the coffee. However please note that the lead containment is very low for brass and thee chance of having lead on the outside of a mug is even more unlikely, lastly you won’t die from a few lead atoms. Some printer suppliers (like e3d) offer stainless steel nozzles for absolute food safety, Secondly they offer hardened steel nozzles, which should be just as food safe, but additionally hardened steel nozzles are incredibly wear resistant, meaning the metal won’t wear down during printing.

2 Likes
7

Good to know that Colorfabb XT is food safe.

I seen on the engineering drawing of rep rap pro quick set nozzles it’s states material as stainless steel

Also, just to add proto pasta recommend that you use a hardened nozzle when using their metal based filaments due to wear

8

Sweet! I didn’t know XT is approved food safe. My win for today :slight_smile:

Cheers @MB3D!

1 Like