Printing of porous structures - dimensions

Hello everybody!

I started using Form2 and Form3 some months ago, to carry on research on porous structures, using Flexible (V2 and then 80A) and Elastic50A resins.
At the moment, I’m able to design and print porous structures with interconnected pore size of 2mm. When I try to print samples with pores less than 2mm, problems start arising. I think it’s related to the washing in IPA: it’s like the solvent does not enter the inner part of the sample and cannot wash away the uncured resin. As a result, the outer part of the structure is porous and the inner part is non-porous (since the resins are transparent, it can be seen at naked eye, although we have run micro-ct tests to prove that).
I have read on the support pages that it might be necessary to use syringes to direct IPA to fully wash the samples, but at the moment I would like to try other methods.

I was just wondering whether any of you has/is working on this topic and can give suggestions.

Cheers,
P

Have you tried using ultrasound cleaner with DPM?

I’ve been unisng ultrasound cleaner, but only with IPA.
Excuse the silly question, what would change by changing the solvent?

We found that DPM does not become “loaded” with uncured resin as quickly as IPA. Plus IPA in most ultrasound cleaners is incredibly dangerous. IPA has a very low flashpoint and the ultrasound action will quickly take the IPA up to that.

How long do you leave the part in the ultrasound cleaner? what frequency does your cleaner operate at and what is its power? - those are all factors that affect how well it cleans.

A $100 ultrasound cleaner will not work as well as the more powerful and expensive ones.

Using IPA in a Vapor Degreaser or Ultrasonic Cleaner? | MicroCare.

Thanks for the safety tips :sweat_smile:
I was thinking about increasing the washing time (currently, I’m doing what suggested by Formlabs - 2x 10 min cycles), even though the mechanical properties will be affected as well.

“Even though the mechanical properties will be affected as well” - umm, we don’t find that using DPM. Its only removing uncured resin outside the body of the print and as such should not be an issue. Post cure exposure simply ensures any material that is within the print body becomes cured.

It is agreed that there will be some degree of porosity created by uncured material within the body but in reality with a decent print profile this should not dramatically affect the overall mechanical properties