Which Formlabs resins can I use for printed parts that are in contact with oxygen


#1

We need to print on Form3 parts that will be in contact with oxygen - and the customer also requires a certificate from us that the printed material is suitable for use in contact with oxygen. ( I don´t know if Formlabs provides anything like this? ) I haven’t found any information about that - although it’s possible I was searching by wrong way. Thank you for help!


#2

I’d be surprised if O2 was a problem for any resin. Oxygen can inhibit the resin curing process, but if the resin is cured it shouldn’t have any effect. FL would obviously have to say for certain, of course, I’m just guessing.

But… what will the Oxygen be used for? If it’s carrying gas that is going to be breathed by a person, a bigger question might be if the resin is biocompatible in that application. If it’s under high pressure or low temperature, the resin may not be mechanically compatible with the use case. And if there is a safety concern should the part fail, you might want to be sure you’re not going to be liable for any failure of the part…


#3

Maybe you could ask Formlabs themselves? Send them an email!


#4

It is supposed to be a protective cover for the end of the oxygen hose that is used to pump liquid oxygen into the tank from the tanker trucks. The cover should serve to prevent from entering the hose dirt - but also mice, flies, fallen leaves - when the hose is not in use and laid on the ground. The hose is unpressurised but there may be oxygen vapours and spontaneous combustion could occur if those vapours react with oils and grease if the material from which the cover was printed contains them. It’s technical oxygen, it’s not for breathing, so biocompatibility is not involved. The question is: after curing, can resins contain residual oily, greasy materials that that oxygen can react with?

Translated with www.DeepL.com/Translator (free version)


#5

Don’t be surprised if FormLabs doesn’t want to make a recommendation regarding use of their cured resin with liquid oxygen.


#6

I didn’t pick up on “Liquid”. LOX is going to be around -180ºC. I’d be surprised if FL would rate any resin to that low a temperature. I would not expect the resin to survive the cold. But it’d be a mechanical failure, not a chemical reaction.


#7

Once again: the hose after pumping liquid oxygen will be laid on the ground, it will be empty, without pressure, without liquid oxygen and without low temperatures. The cover has only one job: to prevent any dirt from getting into the hose, but there may be oxygen vapours in the hose…
I have written to support, so far they have not replied.


#8

One thing to note, I believe all cured Formlabs resins are flammable. So if there is an ignition your cover will burn. I did some testing with this way back when, and created a custom mixture with flame retardant to reduce the flammability. My spidey sense thinks Formlabs was investigating an official flame retardant resin but nothing announced yet.

Sorry I don’t have any info on oxygen reactivity.


#9

Print a “Witness Slip”, some random small shape, and expose it to the expected levels of O2 and see what happens… Empiricism isn’t a dead art. :slight_smile: