Optimising print supports: Form 4/L and engineering resins

[Davidwedge]

@smerrett

It’s really helpful to hear details on your workflow. Thank you. I am wondering what the waste stream looks like for the Simple Green with resin mixed into it. Is the SG recoverable? Could you please shed any light on this or its disposal? We are looking at a solvent recycler and probably a 2nd stage of IPA prewash/sluice but I am intrigued by your multisolvent process.
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The longer supports SEEM to make parts removal a bit easier on occasion.
But the longer the supports, the more flex, and then thinner rafts will tend to stay stuck on the flex head…

I did a separate writeup about our multi-stage cleaning system.. i actually left 2 steps out in the notes here, in an attempt to keep it simple.

We focus on production. Yes, there’s testing/prototyping, but once a part is locked in, it’s loaded full-up on a plate, and run. sometimes we run the same build (say 50 parts on a plate) for 20x’s without stopping… so we go thru a lot of resin - usually 10 liters/week (we’ve got several form4s).

So, the issue with workflow isn’t just “saving IPA” - it’s a huge time savings.

1. SG is $8/gallon at Lowes. IPA is ~ $20/gallon on AMZ.
2. we don’t like the idea of dealing with loads of IPA to ‘get rid of’, from an ecological perspective, and we also don’t like to have to recycle a lot, so we hacked up a recycling system off a whiskey still from AMZ.
3. This still requires a lot of time (to recycle) - it can take most of a day in the background to run 3 batches of 10 L of IPA thru the still, and even though we do it while running other jobs, it’s an annoyance..

About SG - we’ve not YET (13 months in) hit a point where the SG can’t be cleaned/dried out, and reused… it’s slightly less effective, AND it takes a while to ‘dry out’, but it’s been cycled repeatedly.

To ‘clean’ the SG, we pour the ‘used’ into a tall/narrow jug (to speed up gravity separation), and leave it in a dark corner for 3-4 days. The resin settles to the bottom and gets very grey.
Then we take the jug of it out, leave it on the dock for a few days to harden in the sunlight.
After 12hrs in the sun, it can be slowly poured off the top, the ‘sludge’ in the bottom is then poured out into a pan, left to harden in the sun, then it is handled as an inert plastic.

So, current work flow:

• Pop off entire raft with product. no separation or hand-cleaning.
• Drop entire raft into our 5 gallon SG wash system.. 10-20 minutes (depends on what else is in downstream washes)
• Pull raft out of SG bucket, pop parts off into FormWash with SG. Formwash SG runs 10 minutes.
• Shake off excess SG into FormWash, then ‘slosh’ in & out of a “dirty” container of well-used IPA (primarily to remove excess SG prior to final IPA wash)
• IPA wash in FormWash2. 5 minutes
• Shake & drip-dry - 3-4 minutes in room temp.
• 3 minutes in Form Cure.

This minimizes the amount of wear on the IPA, product comes out clean and dry, and we are able to make 30L of IPA last about 10 days prior to running thru the recycling system.