Question on different resins

[armored76]

Hey,

 

THE one thing that is holding me off from getting my own SLA printer (and I'm telling you that finger is itching!) is the handling of the UV resin. It really seems like a horror material that you shall handle in your best Sunday anti-chemical suit somewhere in the remote mountains then burn down the place to make sure you are not contaminating anything.

 

In this context, I was wondering how these UV resins actually compare to good old 2K PU resins (like those from Troll Factory) that were around for a few years now. Now I realize those shall be handled with care, too but I had the impression the 2K stuff is far less sensitive in this respect.

 

Can someone with deeper knowledge on the mechanics behind the chemical components share a bit of light on this?

 

Thank you!

Cristian

 

[Bangseat]

Be interested to know where your concerns originate - yes it is poisonous, but the product safety advice (wear gloves) is not exactly stringent. 

 

I gather some are sensitive to the resins and have reactions to getting it on skin, I've had a few splashes and no effects. Some resins smell strong, Elegoo doesn't and I've never had a headache from it. 

 

The bottom line for me is, it isn't aerosol, so I'm not breathing it in as I would if I was spraying Alclad without ventillation. The other thing to consider is, you don't actually spend that long exposed. I take maybe 15 minutes to empty and clean my tank, top up and set the printer going again. After that the resin is contained - and actually I only clean the tank every 5 prints or so, or after a failed print. Parts clean up - well, at least getting the goo off, which is where you are at most risk of getting it on you - doesn't take long either. Compared with mixing PU resin for moulding, it's a much cleaner and quicker process. 

 

 

[armored76]

Thanks for sharing your view, Bangseat!

 

Since I don't have the printer and materials myself,I have to rely on second-hand information I get from forums and Youtube. Now, I realize how this kind of information may be biased as we live through times where this comes so obviously visible. Still, I prefer to err on the safe side.

 

I might be overly cautious but the way I see this is that the resin cannot be used in a hobby room, for instance. No matter how well the area is ventilated, it would still not be able to remove all residues from the air. Then again, these don't only get into the air during the (4-8-12 hours?) print but also during curing... and maybe even after that for a while? It seems like it is best operated outside or a dedicated room that has very well ventilation (shed, patio, etc). I've seen a lot of people saying they operate the printer in their garage or basement where they don't do much other activities.

 

There is a reason why you shall wear a mask when handling it and - please correct me if I'm wrong! - I don't think these will cause headaches in most cases but other long-term damages to lungs and respiratory apparatus. That and the adverse reactions some might get after direct skin contact or the materials leaking through the skin into the lymphatic system.   

 

Again, I don't pretend to be the "holder of the seven keys" in this matter! I'm just trying to form an educated opinion before engaging into a decision. 

[qn30jEkPz7]

This thread is written by an expert in the field and links to safety advice 

 

 

[qn30jEkPz7]

17 hours ago, Bangseat said:

it isn't aerosol, so I'm not breathing it in

Just to note that simple evaporation can be harmful for some materials without needing them to be aerosols and that even short individual exposures can add up to cause cumulative harm and sensitisation. I’d absolutely err on the side of caution

[armored76]

3 minutes ago, LostCosmonauts said:

Just to note that simple evaporation can be harmful for some materials without needing them to be aerosols and that even short individual exposures can add up to cause cumulative harm and sensitisation. I’d absolutely err on the side of caution

That's the perfect wording of what I was trying to say  Thank you!

 

To get back to my initial question... Resins used for printing seem to be more "dangerous" than pour-in resins used for mold casting. Am I getting this right?

[qn30jEkPz7]

*With the big caveat that this isn’t professional advice*

 

Probably about on a par - I’d treat both with respect and minimise my exposure with a solvent capable mask, good ventilation and gloves. The printing resins aren’t a million miles away from those you’ve had cure in your mouth if you’ve had white UV curable dental fillings but you’d not want to have a few of those a week. 

 

Modellers tend to be a bit lax about 2k PU resins and materials. Isocyanates etc. I tend to treat them with much more caution than most both because my Dad spent years happily model making in sheds surrounded by balsa dust, cyanoacrylates etc. and dismissing concerns about ventilation but now has absolutely knackered lungs & very limited life expectancy.

[ratsmitglied]

I personally would say that it depends on the resin you're using as much as anything. I run an air purifier with an activated carbon filter next to my printer at all times that it has resin in it to filter out as many of the fumes as possible, but I know that other people have set up extraction fans and run them in an enclosure to vent the off-gasses outside. My experience compared to casting resin is that they are similar in terms of the fumes, but the casting resin isn't usually left sitting out like you do with photosensitive resins.

 

I would agree with @LostCosmonauts that modellers tend to be a bit lax about safety on all the chemicals that we use - and would say that the photosensitive resins are no worse than many of the other chemicals that we use, the main difference being that instead of being a tiny little nozzle you're using larger amounts, not only of the resins themselves, but also IPA or an alternative cleaner for the resin. Based on the MSDS of the mould casting Resin I've used and the MSDS of the photosensitive resin that I use I would say they're about on par with each other in terms of safety, with most of the advice being the same.

[armored76]

Thank you, gentlemen! Your answers are much appreciated!

[Anthony Kesterton]

I have seen some info about plant-based UV resins recently which suggests these are less toxic.

https://home3dprints.com/is-plant-based-eco-uv-resin-for-3d-printing-worth-it/

 

The toxicity of "normal" UV resin has made me think twice about looking at 3D printers.

 

 

[armored76]

I've read about the "eco" resin, too but I think that despite the fact that the starting material might be less dangerous, the additives that turn the oils into a resin make up the lions part of toxic materials. So, yes, these are probably less harmful but still a way far from being safe.

Again, this is just my gut feeling so please feel free to teach me better!

[Anthony Kesterton]

1 hour ago, armored76 said:

I've read about the "eco" resin, too but I think that despite the fact that the starting material might be less dangerous, the additives that turn the oils into a resin make up the lions part of toxic materials. So, yes, these are probably less harmful but still a way far from being safe.

Again, this is just my gut feeling so please feel free to teach me better!

Ah - that is a good point.  I have no experience with either material at the moment - but been trying to read up as much as I can.

 

anthony

[Circloy]

On 30/08/2020 at 07:08, LostCosmonauts said:

This thread is written by an expert in the field and links to safety advice 

 

 

Sound advice  - I'd add to it by suggesting that containers of resin, and printers, should be stood in trays of sufficient capacity that if leaks were to occur it is capable of fully containing the leaks.