Adhesive backing FEP Teflon film
Hi all and again thanks to Ahmet ( from the Yahoo group )for sending a sample to me.
I have tested extensively the Adhesive backing FEP Teflon and am abandoning that
route for now. It seems to have the same problem as straight
polycarbonate/nylon/Polyethylene. It is difficult to separate the resin ( at
least mine )without it actually coming off the glass base. You could be using a
different resin with different results, but for my purposes it does not work.
Cheers!
That’s unfortunate about the FEP not working. What are you planning now? Do you have a set of criteria for an ideal release film? I could guess a couple:
1. won’t separate from vat floor
2. transparent to UV and high frequency visible light
3. will release easily from cured resin
I’m really interested in how you determine #3 without just experimenting. How did you decide to try the FEP material?
@ChrisO I still have the regular FET Teflon
I bought some non backed FEP in 1 mil thickness to test some laminating of surfaces for changing hydrophobic/hydrophilic properties as well. I was curious as to whether anyone who already has a working photo printer rig with a polycarbonate or similar pliable/flexible grade bottomed vat has thought of or tried some sort of deformation of the tank bottom from the bottom exterior side to encourage the solidified part to come up and away from the bottom and ease pulling pressure on the top holder plate adhesion? It would have to be a careful wide area deformation with a smooth semi-curved surface plunger or piston pressing the bottom face with a evenly distributed stroke over several centimeters of the vat bottom but it would seem a lot more efficient mechanically and maybe even easier to implement than the vat rocker/roller tilting mechanism. Also a similar deforming de-plying/peeling or back-springing could be done from the bottom outside by having the bottom plate mounted in a metal rimmed framing with a sort of hinge or pivot at the midipoint and then the metal framing is racked downward and inward by a leadscrew across the frame sides being driven to draw the sides closer which would deform the plexiglass or acrylic polycarbonate by a few degrees of deflection and then release it back in a springing and unloading motion for a few cycles. Anyway its just a thought and I guess I need to get busy testing some of these ideas myself instead of formulating and hypothesizing so much…. hehehe. I hope to see more reports and progress soon on your blog and once again thanks.
I am look for FEP film (Fluorinated Ethylene-propylene film),do you know how can I find it?
LOL Plastics companies and DuPont of course.
I’m no expert on this matter and I haven’t read through all the information on this website, but have you thought of floating the resin on a thin layer of clear liquid with a bigger density? Something the resin does not react or mix with… Your biggest challenge would be finding such a liquid and eliminating vibrations, shocks, etc… but it might be worth investigating. It’s the same idea like making glass sheets or nylon. Congrats with your progress on this very nice project btw!
We in the group have discussed that possibility, but to date have not gone too deep. Trying to keep it KISS.
Cheerio.
ok what i have understood is that u use The “FET” teflon film. nevertheless i am not able to find FET Teflon-film in the Internet. what i can find is FEP Teflon Film and thousands of PTFE variants.
please clarify this for me.
another question is: how do u stick the film to the vat?
did anyone tried a curing teflon spray? maybe PTFE-Spray?
Hi Martin, I cannot find in the whole website “FET”, but yes I use FEP Teflon film. The film is stretched a little between two plexi sides and I use the office binder clips to secure it. It also comes up the sides so the resin does not come in contact with the VAT. I have not tried Teflon spray or PTFE. If you have some trials please post the results in the Yahoo group please ( you can find it under the “Other 3D printers” section ).
Thanks!
Peter
ok Thank you. that clarified it for me.
“arch 11th, 2012 at 22:51 | #2
Reply | Quote
@ChrisO I still have the regular FET Teflon
”
that confused me
another question raise from your explkenation:
yoa say “The film is stretched a little between two plexi sides and I use the office binder clips to secure it. It also comes up the sides so the resin does not come in contact with the VAT”
if the teflon-film is not sticked to the VAT directly and u print in the middle of the VAT/FEP-Film , will it go up and stretch until it is released from the cured resign? or is the non-sticking so good that it wont stick totally?
i mean after thousands of layers scretched the film a bit it will loose its planarity?!
i will try the PTFE Spray when i found a Glassmaker with a good price for mor then one VAT
will post the result on yahoo-groups when ready
Thank you Peter
Martin
Hi Martin,
The film is tentioned so it has some spring to it. The teflon film is not “that good”. The resin sticks to it and when lifted you can hear a thump of the foil springing back to the bottom of the VAT. After 14 build platforms X roughly 1200 layers each printed it is still good and planar.
Peter
I am working on some fluoropolymers, using this like a coating layer on glass, i got problems that the coating is different to coating another layer of other materials on it, maybe you can try this fluoropolymers coating materials to help you to get a nice lift of your art. “Cytop fluoropolymers 809″
Hi Guo Yuanyuan,
I have not been able to use a coated glass to get a clean “lift off”. The vacuum force is just too great at the resolution I’m printing in.
If you have some new material/process that you would like for me to sample I can do it.
Cheers!
Peter