Your rationale seems to be good as to transmissivity data- BTW the word does stem from "transmissive" and at least it exists now- of plastic I'd expect opticians to know, but my faith and trust remains in the engineers in the plastic industry the manufacturers know and are willing to share such information about their specific product. As far as mounting goes, we're limited only by our imagination. (I know that you and most everyone else already know this, just mentioning it for those who might not.) But all this is interesting and if suitable UV filtering materials can be found in large sheets, I can think of a few applications in the company I work for. The plastic cover plates are cheap insurance against injury and keep the more expensive filter plate from getting spatter stuck to it.
I think the idea of every shield needing more that one lense comes from using glass filter plates for welding, that they can shatter from impact or from heat encountered in welding. I don't know if that gives me a #14 or #15 but I know my eyes like it better at the end of the day. We don't usually have them in the tool room, so I combine a #10 with a #4 or #5 burning lense. I like to use a shade 14 when welding with FCAW at 250+ amps.
Also, I would think an optical materials supplier would be better able answer questions about UV tranmissivity (is that really a word?) I don't know why you can't have more than one of the combo tinted, just that normally one plate gives the protection needed. Just that tinting is possible on a small scale, so I would think someone might do it on larger sheets, and it might be commercially available.
#SHADE 12 WELDING LENS PORTABLE#
Every shield should have more than one lense in it (and the wearer should also use safety glasses behind it)- I understand the suggestion is that only one of the combo should be tinted? If it's a mounting or restraining design issue for impact protection in a portable face shield this would not pertain to the design of a window, would it? regards dĭee, Actually, my thinking was not about any specific number of layers of material. Any insights on the subject would be appreciated. reasoning behind any possible hazards escapes me. I think I got the impression it was OK from Jackson instructions or perhaps comments online around here somewhere in the context of adjusting fixed shade automatic safety lenses ("blinkers"). I'm also concerned about the heads-up about doubling up tinted lenses.
I cant advise about materials- that's out of my area. I have suspicions but don't know for sure if it's the polycarbonate material itself that provides the UV filtering I'm sure there is a supply source for plastic sheet that can provide same in a variety of tinted shades off-the-shelf. CH, I regret that I'm unaware of the composition of standard lenses for welding helmets.