Release coating for glass
Posted: Wed Jan 15, 2014 10:14 am
I've been experimenting with release coatings adhered to glass. These release coatings are platinum cured Si-H/Vinyl systems which are used to make release liners for the adhesive industry. The major issue with these coatings is anchorage to the glass. If the coatings are not anchored properly they will be destroyed as the build plate is moved away from the vat. The best test for anchorage is to rub your thumb repeatedly over the coating with firm pressure. If the coating is anchored, it will stay in place, if the coating fails anchorage, the coating will crumble into a clinky sand like residue.
I tried to use a vinyl triethoxy silane as an anchorage primer for the glass, but the coating still rubbed off. I then tried applying Tyzor TBT (Tetrabutyl titanate) as a primer to the glass form 5% solution in heptane. I wiped on the TBT primer and dried it from 5 minutes at 150C. I then coated the TBT primer with a 50% solution of platinum cured silicone, and tried again for 3 minutes at 150C. So far, the coating is really on the glass, and surviving the rub test repeatedly. I've tested the release of the coating with duck tape and it did not stick to the coating.
Now I just have to build a printer and test it out.
I tried to use a vinyl triethoxy silane as an anchorage primer for the glass, but the coating still rubbed off. I then tried applying Tyzor TBT (Tetrabutyl titanate) as a primer to the glass form 5% solution in heptane. I wiped on the TBT primer and dried it from 5 minutes at 150C. I then coated the TBT primer with a 50% solution of platinum cured silicone, and tried again for 3 minutes at 150C. So far, the coating is really on the glass, and surviving the rub test repeatedly. I've tested the release of the coating with duck tape and it did not stick to the coating.
Now I just have to build a printer and test it out.