Resin prints/components are s a core part of my business making motorcycle accessories. I love the strength of Formlabs resins, the quality of the prints, and the speed I get on the Form 4 compared to other additive manufacturing methods.
However what I haven’t liked about resin printing over the last 5+ years is dealing with dirty IPA. My wash gets saturated too quickly too often and the turnaround time for my IPA supplier is 3-4 weeks for the quantity I order. I also need a secondary clean IPA container on hand to rinse the Tough series prints for a clean, matte surface finish (for painting with Cerakote). Lastly disposing of IPA is a chore, as most services that pick up used solvents require a minimum quantity that I just don’t have at the moment. As an aside, I have used some cellulose filters in the past to cycle through the pigments in my washes, which helps with clarity but doesn’t completely reduce saturation. IPA really has been the sore subject in my manufacturing process… until I met a guy named Phil.
Phil (@leonhart88) from Ember Prototypes shared his experience a while ago with solvent recycling (using a Uniram URS500). I had never heard of this process, but essentially it vaporizes a solvent by boiling and leaves the contaminants behind. Leaving you with a separated clean, pure IPA in a catch container, and the residue inside a thermal resistant ‘trash bag’. The returned IPA is a little lower each time you recycle, as any air trapped in the vat gets condensed as well and deposited in your container, however it’s relatively marginal and the resulting IPA is a few percentages lower than whatever you put in it.
The main issue with this process, is the cost of the equipment. There are some distilled options others have used from less expensive amazon wine distillers, however I personally do not want the risk associated with using it. A brand new Uniram 500 (5 gallon capacity) costs $5k brand new. I could not economically warrant that much money as I’m not going through that much IPA at the moment. HOWEVER…
For months I continued to search for used units, most of which ran $2-3.5k and were NOT well maintained or cleaned per the manufacturers instructions. Recently I came upon a Facebook post for a BRAND NEW unit…for $1250 USD. I could not pass that up - so I messaged the seller and picked it up a few days ago.
I’ve run all of my dirty IPA through it in 3 batches, about 12 gallons. Because I can’t dispose of IPA in my area, I had to save everything and just store it. Well now that I have this unit, it’s already reprocessed about $300 of IPA that I DON’T have to buy. I will have to replenish what I have on hand, as there is some evaporation during the recycling (manufacturer states 1/8gal per cycle), but this will significantly cut down my IPA costs and I will likely start processing parts more often now that I don’t have to wait around for fresh IPA restocking. At the cost I paid for the unit, it should pay for itself well within a year. Each cycle takes about 4-6 hours depending on how much IPA is poured in. There is some residual IPA left over in the tank - the condensed vapors creep in behind the bag, so there is a little bit of cleanup when the bag is removed, however it’s clean IPA so not a terrible clean up job.
The seller ALSO has another brand new unit available, so if anyone is interested send me a message, and I will forward your contact info to them for them to reach out. They are a chemical distribution company located in Roaring Springs, PA here in the US.
The last bit of my dirty IPA in the Form Wash before recycling.
Into the Uniram URS500!
The schmootz leftover! Looks like goopy Tough2k (which is what was washed in it).
Condenser cools the vaporized IPA, and drains it into my clean contained.
Fresh IPA ready for the next batch of prints!
