IPA recovery system interests?

[Chad Gardner]

I have been working on recovery of IPA after seeing how much I was spending on it monthly. I have come up with a simple filtration system that can be made for $50-150, depending on how much IPA you’re filtering. Bigger tank = more filters = more costs. Been using the same IPA for months now and took a sample to a local university chemistry professor for analysis and it came back 97%+ IPA and the original 99.99% bottle tested 99.111%. Only problem is it’s slow. Takes about a week for 4 gallons to be cleaned. Does anyone think there is a market for simple IPA recovery at such a slow rate? If so, what size would be ideal? 1-2 gallons = 1 filter and tanks for about $50. Above that and you need 2-3 filters. The filters are good for 10k gallons of water, so far they have done about 80 gallons of IPA and are doing great. And you get back about 91-93% of what you put in, so you’re losing some but what you get back is as good as a fresh bottle.
Is the rate just too slow? I’m toying with pressurizing the tank to speed it up, but that will increase costs. Thoughts? Waste of time? Already been done? Not needed?

 

[JMN]

I have been working on recovery of IPA after seeing how much I was spending on it monthly. I have come up with a simple filtration system that can be made for $50-150, depending on how much IPA you’re filtering. Bigger tank = more filters = more costs. Been using the same IPA for months now and took a sample to a local university chemistry professor for analysis and it came back 97%+ IPA and the original 99.99% bottle tested 99.111%. Only problem is it’s slow. Takes about a week for 4 gallons to be cleaned. Does anyone think there is a market for simple IPA recovery at such a slow rate? If so, what size would be ideal? 1-2 gallons = 1 filter and tanks for about $50. Above that and you need 2-3 filters. The filters are good for 10k gallons of water, so far they have done about 80 gallons of IPA and are doing great. And you get back about 91-93% of what you put in, so you’re losing some but what you get back is as good as a fresh bottle.
Is the rate just too slow? I’m toying with pressurizing the tank to speed it up, but that will increase costs. Thoughts? Waste of time? Already been done? Not needed?

Go wider, not deeper. Parallelism. BIgger filtration intake face surface area will get you higher throughput. Or multiple side by side small units. Smurfing.

 

[Chad Gardner]

I have some new short wide filters I’m hoping will help speed things up. So you think multiple, maybe 1 gallon tanks?

 

[Contraluz]

? Waste of time? Already been done? Not needed?

Pardon my ignorance, but what is the cost of a gallon of IPA? I am in the market for a printer, but I have not looked at that part, yet, and I am all in on not wasting resources! So, I guess it comes down to cost of filters, your time etc vs cost of a gallon of IPA.

Oh, and what printer are you using and are you happy with it?

M

 

[Chad Gardner]

Pardon my ignorance, but what is the cost of a gallon of IPA? I am in the market for a printer, but I have not looked at that part, yet, and I am all in on not wasting resources! So, I guess it comes down to cost of filters, your time etc vs cost of a gallon of IPA.

Oh, and what printer are you using and are you happy with it?

M

99% IPA ranges from $15-30/gallon. I was using up 3-4 gallons/month, sometimes more. It adds up.
I have a Form3b, old Moonray and EnvisionTec D4K. Like everything, they have pros and cons. Beats the heck out of stone in many ways: fit is better IMO, no bubbles, doesn’t break, etc. You have to get past the learning curve, but I still question the benefits bc stone never needs calibrated, updated or locks up when you’re in a hurry, but the prints are so dang accurate.
Gotta have a good scan/impression first and foremost. Printers are great when all goes well but will piss you off when it doesn’t. It just depends on if you like technology and are willing to deal with the problems computers can bring. I like technology so I enjoy it.
I like the Form3b best for an all around printer.

 

[CoolHandLuke]

throw UV light on the tank, filter the debris that solidifies through mesh or layered paper. one pack of coffee filters is like 2$

 

[Chad Gardner]

throw UV light on the tank, filter the debris that solidifies through mesh or layered paper. one pack of coffee filters is like 2$

Yes it works but the coffee filters only catch so much stuff. At best I was getting 70-75% IPA with 5 filters measured with a hydrometer and I lost about 15% of my initial IPA, I guess to it being absorbed by the filter paper.
This uses UV light and returns 97%+ IPA after 4-6 months of heavy use with “an insignificant amount of organic and inorganic impurities.” A different unopened bottle from the original order had 0.2% impurities in it according to the tests run by some grad students. So like the chemistry professor said, it’s actually cleaner than the original IPA, minus some loss of IPA to natural breakdown.
It’s easy and cheap, as you just pour it in and let it filter while the UV light does it’s thing. You just have to have 2 sets of IPA washes or you just draw out whatever is needed from the clean tank, use and return it to the dirty tank keeping a constant cycle of clean IPA available.


I wonder if there’d be a market for it for at-home printers? I had to build one for the chemistry professor bc he likes to print as a hobby and said his wife stays on him about the IPA costs.

 

[Chad Gardner]

 

[CoolHandLuke]

Yes it works but the coffee filters only catch so much stuff. At best I was getting 70-75% IPA with 5 filters measured with a hydrometer and I lost about 15% of my initial IPA, I guess to it being absorbed by the filter paper.
This uses UV light and returns 97%+ IPA after 4-6 months of heavy use with “an insignificant amount of organic and inorganic impurities.” A different unopened bottle from the original order had 0.2% impurities in it according to the tests run by some grad students. So like the chemistry professor said, it’s actually cleaner than the original IPA, minus some loss of IPA to natural breakdown.
It’s easy and cheap, as you just pour it in and let it filter while the UV light does it’s thing. You just have to have 2 sets of IPA washes or you just draw out whatever is needed from the clean tank, use and return it to the dirty tank keeping a constant cycle of clean IPA available.


I wonder if there’d be a market for it for at-home printers? I had to build one for the chemistry professor bc he likes to print as a hobby and said his wife stays on him about the IPA costs.

you don't want to be using too strong of alcohol to begin with, because of this filtration principle. if you start with 85-91%, you end up with roughly equivalent after filtration because the particles of resin trap some alcohol, and some alc will have evaporated in the process, removing the resin brings the overall % back to rough equivalent.

 

[CoolHandLuke]

for years 3dsystems 3100-4100 printers used to have you dunk prints in ice cold alc after coming out of the wax melting oven; the temperature shock turned model resin white, and froze remainder wax.

for resin the idea would probably be best to splash some water in the ipa to allow the alc some heat absorbing insulating qualities so that the vat doesnt evaporate too quickly, evaporation would cause the alc % to increase and lead to quicker saturation.

 

[Chad Gardner]

you don't want to be using too strong of alcohol to begin with, because of this filtration principle. if you start with 85-91%, you end up with roughly equivalent after filtration because the particles of resin trap some alcohol, and some alc will have evaporated in the process, removing the resin brings the overall % back to rough equivalent.

I think I see your point about the loss of IPA, but the manufacturers recommend 95%+ IPA or ethanol for most resins, don’t they?
I just did a webinar on Bego Permanent Crown resin and they recommend 95%+.

BTW, that’s what’s in the photos above. Look at the bottom of the Formwash. That resin saturates IPA fast! Initial hydrometer reading was 20 proof, 40% IPA. I believe it was 2.5 gallons initially in the Formwash and I recovered 2.1-2.2 gallons at 97.236% purity. I have the exact numbers at the office but pretty sure that is what I got. That stuff was so saturated the Formwash wouldn’t start the spinner. I used it as a prewash while beta testing from August 2020 to January 2021, so I know I lost some to evaporation, but was amazed how it turned what most would consider useless IPA into almost pure IPA.
Again, I may be wasting my time but it works for me. I even have a way of pressure washing from the clean tank at 50-60psi and all the dirty IPA goes back into the dirty tank to be refiltered. Completely closed system. Only issue is IPA fumes when I open the wash tank, but I have a filter ventilation system I’m going to install.

So you think I’m wasting my time trying to create this product or you see it as unnecessary? I’m looking for all points view.

 

[Chad Gardner]

for years 3dsystems 3100-4100 printers used to have you dunk prints in ice cold alc after coming out of the wax melting oven; the temperature shock turned model resin white, and froze remainder wax.

for resin the idea would probably be best to splash some water in the ipa to allow the alc some heat absorbing insulating qualities so that the vat doesnt evaporate too quickly, evaporation would cause the alc % to increase and lead to quicker saturation.

Interesting idea. Ty.

 

[zero_zero]

The biggest waster of IPA at my place of works was the formlabs washbucket , since I got rid of it and started using two smaller ziploc containers on top of two cheapo magnetic stirrers, I am saving big. I am buying my IPA form a chem supply company for much cheaper than "dental" which also helps

 

[Cleo]

I would buy that product. good idea

 

[Chad Gardner]

I would buy that product. good idea

What size tank would you recommend? 1 gallon, 2.5G, 5G?
I’m going to try these shorter, fatter filters this week to see how fast and well they filter, and if they work, I’ll send you one to test it out for me and give feedback.

 

[Chad Gardner]

The biggest waster of IPA at my place of works was the formlabs washbucket , since I got rid of it and started using two smaller ziploc containers on top of two cheapo magnetic stirrers, I am saving big. I am buying my IPA form a chem supply company for much cheaper than "dental" which also helps

I agree about the commercial washers. Use way too much IPA. I was using the Formwash bc I was beta testing for them. But still using beakers, Tupperwares etc the IPA saturates fast and you can just dump it into this thing and get all your IPA back.
I think you’d get your money back faster than you realize, but IDK. It’s all relative to how much you print.