Printing and Cleaning small injection molds/Thoughts on the new FL cleaner

Hi all! I use our FL 2 printer to create small injection molds for custom products to be injected with soft medical grade silicone. We typically use Biopor silicone. I have problems sometimes with getting all the resin(FL clear resin) cleaned out entirely from the mold. Currently I am using a syringe to individually rinse out each mold with IPA. I essentially force inject the IPA into each injection port and do so until I cant see resin coming out of the drain holes. They all then go through a fifteen minute sonic bath in IPA. Problem is that as thorough as I am, I still have post cured issues with the molds having (I’m guessing) uncured or not fully cleaned molds that will make the silicone come out slimy. I have used a product from Detax called cast separator which works but the whole process takes longer than I would like. Also when the silicone does come out slimy I have to reprint the molds, which is very inefficient. So the question is, any suggestions for more thorough cleaning of the injection molds? They are very small and have small nooks and crannies. I also asked if FL thinks their new cleaner will be able and efficient in cleaning inside small injection cast molds. They say it will but as of now will not offer a return policy if it doesn’t do the job it says it will. Does anyone else print small injection molds and have a similar problem? This is being used in a commercial application so efficiency is key.

Thanks ahead of time!

I’ve had quite a bit of silicone molding in printed molds experience with my F1+. It is essential that you post cure your mold. Really, really post cure it, and there is no substitute for time here. I made a Whiz-Bang chamber, but the Sun is really your friend here. I’ve had best silicone cure results after curing the mold parts in the Sun for several hours. 3d printed molds are useful for prototyping, but certainly not any kind of production system. You’ll also want to use a release agent that does not effect the cure of the silicone. I use and recommend Mann Ease Release 205 for this application.

Good luck,
-C

I soak mine in ipa, agitating them every few minutes
Then I wash with cold water to rinse off all of the ipa

I have found rinsing the ipa off of the part helps cure them better especially any parts that are super thin as it seems to absorb the alcohol to a point

The air dry method has not worked for me, as alcohol always seemed to pool in a certain spot and leave it uncured

I second What Christopher Barr has said… I always spray ease release on my printed parts before pouring silicone… I have even had a little inhibition with tin based silicone on some printed parts.
If I am using Platinum based I will airbrush with a primer to make sure.

What is your preferred primer?