I would like to bond flat resin surfaces together to enclose millifluidic-sized channels. One half contains ports and the other half contains the channels. I’d rather have the channels not be printed as enclosed channels to later be compatible with injection molding processes. Does anyone have any experience with this?
Thank you for reaching out! I would encourage you to check my response from this Forum thread: Gluing glass/borosilicate to High Temp resin. Another potential alternative I should mention is that for thin/narrow bonding surfaces, using liquid resin along with a handheld UV cure can also be a good option for bonding.
For bonding resin printed parts together, the best method IMO is a thin coat of uncured resin between the mating surfaces, and the application of UV light to cure that resin. This yields a bond that (done correctly) is as strong as if the parts had been printed monolithically.
Adhesives for bonding (I’ve used Epoxy and Cyanoacrylate), at least in my experience, produces inferior joints that are prone to cracking (probably because the mechanical properties of the glue and printed resin are too dissimilar).
Thank you for your feedbacks!
What is the largest z-offset I can make with the build plate? I may need something like 2-3 mm. I’d like to try printing one layer, then apply sacrificial wax onto the exposed channels, and then continue printing afterwards to enclose the channels. This method is carried out in this open access paper: https://iopscience.iop.org/article/10.1088/1361-6439/abd9a9
No problem! The largest supported offset is +/- 1 mm (see Fine Tuning Formlabs LFS printers).
Hi @Jesse_K, is it possible in any way to increase this offset range?
No, not that I know of. The only other workaround I can think of would be to build the 2-3 mm gap you need into the model(s) when setting them up in PreForm. The print would need to be paused right at the gap, then the wax would be applied and the print then resumed as you mentioned. I don’t know how this would turn out, and in particular I would worry about the subsequent layers adhering properly to the wax. Trying out a process such as this one would very much be at your own risk.
not to mention clogging if you push some epoxy or resin into the channel/ports when you squeeze them together.
I agree, a thin application of uncured resin on one surface. I wipe off the excess with a towel dampened with IPA and then press them together immediately. clamp and put in the cure station. I’ve done it a couple times and the bond is usually very strong. however, the surface of the cured parts is sometimes warped and the surfaces don’t mate well. I’ve sanded surfaces down to get them to actually touch on long contact surfaces but it’s a lot of work.