TSB
screen printing => Ink and Chemicals => Topic started by: UnderPressureSP on October 23, 2015, 09:21:38 AM
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So yesterday I was surprised to see the new packing method for the diazo powder. It now comes with a pouch that you fill with water and shake. I was going to pour the poweder into a container with a lid and shake but there would be some powder left in the pouch. So I did the method I was told. Filled the puch with 2 ozs of water and folded over the seal and shacked. The powder did not full dissolve like in the bottle and I was left with stains on the lower part of my hand where the water drip down my glove with the diazo as i was shaking. I was wondering if I could get some advice I mixing this new packing since the pouch does not have a seal and folding over seems works just okay. Also it seems not to mix as well compared to the bottle. I was told it keeps the diazo fresh....
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Same experience. It sucks compared to the bottle. Don't have a simple solution besides getting a bottle and pouring it in that to shake. Could use old water bottles or something.
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Same here. Not a fan.
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Hello fellow TSB Members.
The foil pouch does have one significant advantage over the bottle, shelf life. 6-12 months longer at peak sensitivity. Here is the easiest method: Pour the diazo in a paper cup slowly. After adding dry powder to the cup add about 1/4 a bag of water to the emptied pouch, fold over the top twice and swish it around and add any remaining diazo to cup. Use latex gloves when mixing, even with the bottles, to prevent stains. You can add water once more to get all diazo out. You can also add more water to the cup to help mix up. Stir with a wooden stick to mix diazo. I also have seen small jars with lids to seal it and shake the jar, which adds more bubbles than the stir method.
In Southern US, and especially Central America, heat is the enemy of highly sensitive diazo. So the pouches help protect it and it stays at peak sensitivity much longer. The bottles did allow air in and in some long term storage situations that many dealers have when they order in bulk, it prevents dark hardening of the diazo. With the pouches you will get a stronger emulsion with better sensitivity. If the majority don't like this method let me know by PM. For the most part is has solved issues at many companies in hot humid areas.
Here is a list of the amount of water to add to the diazo by emulsion type. The amount of water you add can be a personal preference. Typically pure photopolymers uses less water, pure diazo a little more.
SBQ Pure Photopolymer Emulsions
Aquasol TS 8g-diazo 2-3 oz-water Improves water resistance,
Aquasol HV 8g-diazo 2-3 oz-water Improves water resistance
Aquasol HVP 8g-diazo 2-3 oz-water Improves water resistance
Photocure BLU 8g-diazo 2-3 oz-water Improves water resistance
Photocure TXR 8g-diazo 2-3 oz-water Improves water resistance
Dual Cure Emulsions
Textiles
SP-7500 16g-diazo 2-3 oz-water Sensitizer
Graphics
Photocure PRO 16g-diazo 2-3 oz-water Sensitizer
Advance 20 12g-diazo 2-3 oz-water Sensitizer
SP-9500 16g-diazo 2-3 oz-water Sensitizer
Diazo Emulsions
Textiles
SP-1400 12g-diazo 3-6oz-water Sensitizer
Graphics
Murakami T3 20g-diazo 3-6oz-wate Sensitizer
Murakami TSR 20g-diazo 3-6oz-water Sensitizer
SP-3000 20g-diazo 3-6oz-water Sensitizer .
Alan
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Yikes. Lotta work just for emulsion. I'll stick to mu open, pour and coat photo-polymer
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Yikes. Lotta work just for emulsion. I'll stick to mu open, pour and coat photo-polymer
You think that that's work? Cheapskates like my used to buy gallons, and divide it (and the Diazo) into smaller portions to keep it fresher.
Triple beam balance, orange fingers, the whole nine yards.
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Yikes. Lotta work just for emulsion. I'll stick to mu open, pour and coat photo-polymer
You think that that's work? Cheapskates like my used to buy gallons, and divide it (and the Diazo) into smaller portions to keep it fresher.
Triple beam balance, orange fingers, the whole nine yards.
You can't see my hand raised...but it is. ???
Ohaus digital scale, 5 quart sized deli cups (with lids), 5 Diazo containers re-used myriad times, and a stainless steel frosting knife from the cake store to mix in the freshly mixed Diazo. Works for my normal batch size and always fresh. I still do some manual sized frames, so batching my emulsion usually fits the job at hand. A "fifth" of a gallon does around a dozen (or fourteen maybe) auto sized frames, and maybe twenty 20x24's and I rarely if ever coat both sizes. If I had all one size, I might stop dividing the gallons, but for the above reason, I still divide it up. I never weight the emulsion, just eyeball the filling level in identical deli cups. I weigh the Diazo carefully however. I can go down to a hundredth of a gram, but I don't. After weighing the rather largish variations in the amount of diazo shipped with many, MANY gallons of emulsion... I've decided it just ain't that critical. So a few hundredth's of a gram is close enough.
I am not a high volume shop. Reclaiming over 50 screens a week is unusual. This wouldn't make sense for a most shops, even in the 30-50 screen range.
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It would be nice if you include instructions with the new foil package. Also if you added the cup and stir stick that would also be awesome. I do prefer the bottle shake method over the stir since the diazo dissolves faster. We typically mix one day before use so bubbles are not a problem with the shake method. We do wear latex gloves when mixing I learned that lesson in 2009. I wonder if you could of just vacuum sealed the bottles instead.... On our next batch I will try this method but still not liking the change over. We had never had a problem before with the diazo since we keep it in the temp control room. I would also suggest everyone wear a mask with this method in order not to inhale any diazo particles when pour into the cup.