MarBuc

Just thought of a 3rd option where a PLA mold is split into parts not printed separately but held together by thin PVA layers. Unmolding = 1) dissolve PVA "seals" between PLA parts; 2) carefully remove the PLA mold pieces. Does this sound doable? Regarding e.g. adherence of PVA on PLA?

Hi gr5, Thanks for the mold release tip, as well as your feedback regarding PLA. The part we want to print is quite intricate and I still need to figure out how to unmold it. Option 1 = unmolding by disassembly of the mold. This raises a few geometric issues regarding the design of the mold. Also, a mold split into pieces can lead to silicon leakage at junctions (according to previous posts in this thread)... So this looks a bit tricky. Option 2 = unmolding by destruction of the mold. Mold destruction should not harm the part so "breakaway" might not be well suited. Soluble PVA looks like a good candidate, however the question of resolution must be clarified... As I understand (I have 0 hands on experience so far) : PVA is water soluble, while PLA is not... which would require me to solve the issues in option 1.

Yes, the piece will be quite small (10x10x10 cm max). I have no idea which nozzle will be used... We are experimenting a lot of things at this point, (resolution, molding, medical grade silicon, ...) and we are quite new to 3D printing! So please expect lots of trials and errors. :-) I'll keep the community posted.

We will be using an Ultimaker S5 with a 20 micron resolution so hopefully the finish will be clean. I'll let you know how this molding strategy works out...

Ok :-) One more thing. Do you happen to have a picture of the silicone part that was produced by your client? Just to have an idea of the level of detail. Thanks!

Dear wuzley and Brulti, Thank you very much for your input. I still haven't had the opportunity to try this technique... We should receive our printer in a couple of weeks and I will keep the community posted on our progress. Cheers

Dear Geert, Thanks a million for your comprehensive answer!! I will look into the leads that you mention. The topic looks tricky... I will post here once I have some results! Wish me luck. Cheers 😉 M

Dear all, Do any of you have experience with using PVA or Breakaway material to print molds for injecting silicone? I need to generate quite intricate silicone parts by injecting silicon in a mold, and there are 2 options to make the unmolding possible: Split the mold into separate "unmoldable" parts, then assemble the complete mold, inject, wait, unmold in the correct order. Print the mold in one shot, inject, wait, break away mold. Any advice, comments or sharing of experience would be of great help! Thank you all in advance :-) Marek