Question: There is some confusion here regarding mold surface finish. We don’t care about the surface finish of our molded part, but we need best possible release. Do rougher mold surfaces (like bead-blasted) release medical silicone parts better or worse than smoother surfaces in shear?

Answer: We’ve had our best release results using textured (bead-blasted, etc.) surfaces on our molds. Smooth surfaces (highly polished silicone lenses) tend to be the most difficult to release from the molds. If the surface finish on the final medical silicone part can be rough, I would definitely recommend bead-blasting the mold (number 6 glass beads work well), it’s inexpensive, quick and easy to do and if you make lots of smaller molds, purchasing a bead-blaster to use in-house, is a minor investment that will pay itself off very quickly.

If you have any other questions, please comment or ask me directly at kevin@albright1.com