by vasimv » Thu Jul 11, 2019 9:13 am
Martin wrote: ↑Thu Jul 11, 2019 8:58 am
So you did try PVA (PVOH) + "Speedball diazo sensitizer, right? And, if I'm not misled, "Speedball diazo sensitizer" consists of the diazo stuff only (in form of a powder I assume), correct? In other words, this stuff is not identical with the "Speedball emulsion" (which is a liquid based on vinyl acetate + diazo), right?
If that's the case, you're dealing with a DIAZO but not with a photopolymer system. That said, it sounds interesting - particularly if speed is OK and holograms can be recorded. You might try to contact copy a transmission grating to see if resolution is fit for holography. You then could try gelatin instead of PVA...
Yep, just polivinyl alcohol (well, at least it says so on bag with it, 98% or so). The speedball stuff comes in two cans - speedball emulsion (listed with vinyl acetate in MSDS, about 700 ml) and the sensitizer bottle (there is about 2g concetrated sensitizer which i've dissolved in water as in instruction), i've used just the sensitizer to sensitize the polivinyl alcohol solution. The layer was quite thin but very foggy (seems very concetrated dye/particles or something) and blocked much of light. No holographic stuff (tried to do reflection one) but i've got coins reflections and pva-free areas in shadows. I did that few weeks ago, perhaps i should try again with smaller concetration of the sensitizer and with transmission copy.
The speed was ok, comparable with my FEG experiments (with 405nm laser). It's a bit confusing as was supposed to be used with monomer (vinyl acetate in the emulsion can) but works without too. May be that was because PVA didn't get fully polymerized (not fully dried perhaps) and got washed off by water in non-exposed areas.
[quote=Martin post_id=70993 time=1562853524 user_id=2364]
So you did try PVA (PVOH) + "Speedball diazo sensitizer, right? And, if I'm not misled, "Speedball diazo sensitizer" consists of the diazo stuff only (in form of a powder I assume), correct? In other words, this stuff is not identical with the "Speedball emulsion" (which is a liquid based on vinyl acetate + diazo), right?
If that's the case, you're dealing with a DIAZO but not with a photopolymer system. That said, it sounds interesting - particularly if speed is OK and holograms can be recorded. You might try to contact copy a transmission grating to see if resolution is fit for holography. You then could try gelatin instead of PVA...[/quote]
Yep, just polivinyl alcohol (well, at least it says so on bag with it, 98% or so). The speedball stuff comes in two cans - speedball emulsion (listed with vinyl acetate in MSDS, about 700 ml) and the sensitizer bottle (there is about 2g concetrated sensitizer which i've dissolved in water as in instruction), i've used just the sensitizer to sensitize the polivinyl alcohol solution. The layer was quite thin but very foggy (seems very concetrated dye/particles or something) and blocked much of light. No holographic stuff (tried to do reflection one) but i've got coins reflections and pva-free areas in shadows. I did that few weeks ago, perhaps i should try again with smaller concetration of the sensitizer and with transmission copy.
The speed was ok, comparable with my FEG experiments (with 405nm laser). It's a bit confusing as was supposed to be used with monomer (vinyl acetate in the emulsion can) but works without too. May be that was because PVA didn't get fully polymerized (not fully dried perhaps) and got washed off by water in non-exposed areas.