I was looking for ways to mix UV blockers into epoxy resin (to mix an UV blocker into the solarez zerovoc – the cheapest UV resin I found so far), and I found this: http://www.dymax.com/pdf/pds/3069.pdf
Nothing new here… an adhesive from Dymax that cures fast on UV and blue light… but what catch my eye was the second page… the 2 graphs showing the depth of cure relation with time of exposition and light intensity… And then I realize:
If this product has a depth/exposion time relation, it means that it already partially blocks the light from penetrating deep into the material, which means that we MAY be able to control the cure by just adjusting the exposure time per layer… If we do the math right, we may be able to cure JUST the amount we want from the bottom, by doing really quick expositions, specially if the material is NOT SO FAST to cure… actually, the slower it is, the more difficult it would be to cure a ticker layer… which is EXACTLY what we want!
We could also experiment with adding SOLVENT to the mix instead of a blocker, just to make it HARDER to form the reaction that cures the material, increasing the chances of curing just a tiny layer… just some more to think about it and experiment once we get a prototype working!
Last, but not least, in case someone runs into figuring what viscosity “cP” is, this is a nice useful table to figure how viscous a material is:
|Some typical viscosities (cP at 20°C)|
|air||0.02||motor oil SAE 20||125|
|acetone||0.3||motor oil SAE 50||540|
|linseed oil (raw)||28||treacle||20,000|
|corn oil||72||peanut butter||250,000|
|olive oil||84||window putty||100,000,000|