Used 99% Alcohol

[PRO ARTS DL]

I haven't really seen this discussed before

What are you guys doing to the used isopropyl alcohol that was used to clean resin from 3D printing?

I have read it can be quite harmful if disposed down the drain or in the trash bin.

 

[rkm rdt]

I avoided that and purchased a filament printer.

 

[Foggy_in_RI]

You need to contact a hazardous waste handler.
Be prepared to provide them with your SDS sheets for both the alcohol and resins you are using. They will create a profile and then be able to pickup the waste. Talk to them about how it should be packed.

Another question- what are you doing with the bottles of resin when they are empty? Or the paper towels/cloths that you use for cleaning?

It makes me very happy to see this question being asked but I'm scared to hear what others may say. I remember early on people wanted to print because it was cheap- they had not factored in all the costs of printing including the waste disposal. Some kept it cheap by not caring about contaminating their own water supply... Sad, reckless and selfish.

 

[RCKSTR]

Back into the original bottles and taken to a recycling facility.

 

[SteveD]

Have used for a couple years now. 90% reduction in products going out as hazardous waste

 

[tuyere]

The supplier who delivers our drums of isopropanol accepts them back filled with spent solvent, so everything that comes in goes out, less what evaporates or gets spilled.
That said, it costs us a pretty penny per month to do this, so we're setting up a Sidewinder solvent recycler- this guy: https://solvent-recycler.com/ - it's really just a glorified pot still with a built-in air conditioner-type condenser unit to provide cooling without needing pumped liquid coolant or a lot of airflow for air cooling. That way we'll recapture and reuse our alcohol many times with modest system loss, and the waste products are 1/100th the volume of the current drums of spent solvent, it's just a small mass of solidified dissolved resin from the alcohol that ends up at the bottom of liner bags you just throw out periodically.

 

[Affinity]

Were all doomed. Hooray technology! Do you think a recycling facility doesnt just take your money and drive it to the landfill?

 

[bigj1972]

Back into original bottles, sell at flea market as furniture stain & finish remover.

What doesn't sell gets poured in the river, and the bottles tossed in the ocean.

 

[Toothman19]

I haven't really seen this discussed before

What are you guys doing to the used isopropyl alcohol that was used to clean resin from 3D printing?

I have read it can be quite harmful if disposed down the drain or in the trash bin.

Pour it in a clear container and place it in direct sunlight. This will cure the resin making it sink to the bottom leaving fresh alcohol on top for you to reuse.

 

[Brett Hansen CDT]

Pour it in a clear container and place it in direct sunlight. This will cure the resin making it sink to the bottom leaving fresh alcohol on top for you to reuse.

We do something similar except we just let the alcohol evaporate. Once the resin cures, it is safe to throw in the garbage.

 

[JKraver]

Pour it in a clear container and place it in direct sunlight. This will cure the resin making it sink to the bottom leaving fresh alcohol on top for you to reuse.

We do something similar except we just let the alcohol evaporate. Once the resin cures, it is safe to throw in the garbage.

These are probably the best two techniques currently.

 

[rkm rdt]

Send it to Zero x2 and he’ll return it with a worm in the bottle.

 

[tuyere]

Were all doomed. Hooray technology! Do you think a recycling facility doesnt just take your money and drive it to the landfill?

It isn't a greenwashing thing for the same reason aluminium recycling isn't- it's legitimately cheaper and less energy-intensive to just redistill used IPA than to synthesize more from scratch. Our supplier makes a very pretty penny charging us to haul away the used solvent, processing it, and then reselling it to us for very nearly the same price they sell new solvent from the manufacturer.

On the other hand, there's a company that's claiming to recycle printed material around here, and that's obviously not real, recycling of cured acrylate resin isn't a 'thing', it has no post-consumer applications.

 

[tuyere]

Also- I know an enterprising hobbyist who's working on an automated IPA processing machine that doesn't cost thousands of dollars like a 'real' UL-approved solvent recycler does, it isn't a distiller but instead uses a UV light and a rotating spindle that contacts the surface of the liquid. The UV mostly only cures a skin of resin on the top of the alcohol, and stops when there's a resin skin over the top, so the roller continually picks the cured skin up and rolls it into a big loogie around a paper towel tube or whatever. Apparently it's very good at pulling nearly all the resin out of used solvent, but not as comprehensively as distilling does. It isn't a commercial system yet, but it's very simple and could probably be put together for $100 in parts by anybody moderately handy.

 

[JKraver]

Also- I know an enterprising hobbyist who's working on an automated IPA processing machine that doesn't cost thousands of dollars like a 'real' UL-approved solvent recycler does, it isn't a distiller but instead uses a UV light and a rotating spindle that contacts the surface of the liquid. The UV mostly only cures a skin of resin on the top of the alcohol, and stops when there's a resin skin over the top, so the roller continually picks the cured skin up and rolls it into a big loogie around a paper towel tube or whatever. Apparently it's very good at pulling nearly all the resin out of used solvent, but not as comprehensively as distilling does. It isn't a commercial system yet, but it's very simple and could probably be put together for $100 in parts by anybody moderately handy.

For that effort why don't you just distill it?

 

[tuyere]

Safety, mostly- it's easy to build a pot still, it's another thing entirely to make a pot still that you can safely walk away from when it's got 5 gallons of 99% IPA boiling in its kettle. Part of the reason why the commercial models are expensive, a lot of redundancies to make it impossible to pressurize and explode, and so it fails safe and turns off if anything goes wrong. The resin-spindle thing doesn't heat the alcohol and has no sources of potential ignition inside the enclosure (it uses a 5 RPM synchronous motor with a long shaft to put the motor outside of the sealed tub it operates in),so it's inherently a much safer process that doesn't require constant supervision even if built on a budget.

 

[rkm rdt]

Good thing we don’t put this crap in people’s mouths

 

[ChiJug49]

Best CYA advice is to do research and follow State and local guidance for proper Hazmat disposal.

 

[bigj1972]

Good thing we don’t put this crap in people’s mouths

That's some funny

 

[JKraver]

Safety, mostly- it's easy to build a pot still, it's another thing entirely to make a pot still that you can safely walk away from when it's got 5 gallons of 99% IPA boiling in its kettle. Part of the reason why the commercial models are expensive, a lot of redundancies to make it impossible to pressurize and explode, and so it fails safe and turns off if anything goes wrong. The resin-spindle thing doesn't heat the alcohol and has no sources of potential ignition inside the enclosure (it uses a 5 RPM synchronous motor with a long shaft to put the motor outside of the sealed tub it operates in),so it's inherently a much safer process that doesn't require constant supervision even if built on a budget.

lol didn't lab techs have to process their vulcanite dentures in a blast room? We have gotten soft.