TSB
screen printing => Waterbase and Discharge => Topic started by: ScreenPrinter123 on January 31, 2013, 07:46:37 AM
-
So in trying to do the slow switch over to doing as much discharge as possible to minimize on-press time/get soft hand, is the difference in exposure times. Since we'll either being doing all discharge on prints or a base discharge then plastisol on top, even the plastisol colors will be being touched by the wet discharge base on the print side, and therefore I presume those plastisol screens will have to go on a water resistant emulsion in addition to the discharge base. This will add quite a bit of time to our overall exposure time.
So, my question is, has anyone tried using hardener with an emulsion like chromablue (which is what we use with plastisol)? I figure this has to be considered in two ways: (1) Since the hardener was not made to go on chromablue, will it "adhere" to the chromablue as it would any other emulsion, or would it not? And/or would the hardener itself do anything "weird" to the chromablue making the emulsion unusable for the job? Anyone ever tried this? (2) How does the hardener operate? Does it act like a protective shell or in another way? If like a shell, and the hardener "adheres" to the chromablue as it would any other dual cure/wb emulsion without any negative effects to the emulsion, then why not just use something like a chroma blue with a hardener to cut down on overall exposure time and still have the water resistant emulsion effect? Any pros can provide some insight?
Thanks!
-
Gary Fox told me it should work. It won't last incredibly long like a true emulsion for WB will... but you can do smaller runs this way.
-
tried it, it won't hold up on a auto for more than 50 prints, it's a softer emulsion by nature, we even tried the Chromaline CP Tex supposedly made for discharge, it's pretty aweful too. So far for us Ulano 925 wr, if prepped right works good, Xenon Nova with Diazo is like steel, no hardener needed, or post exposing with the Nova, and we are now using Murikami Aquasol HVP with Diazo and it's got a really nice price point per gal, coats really really nice, holds up awesome on press for discharge or plasitsol printing, and exposes really fast for a Diazo emulsion. Chromoma blue was our favorite for plastisol, but we have been testing to get use into 1 emulsion shop wide, we are pretty sure the Murikami is the winner!
-
tried it, it won't hold up on a auto for more than 50 prints, it's a softer emulsion by nature, we even tried the Chromaline CP Tex supposedly made for discharge, it's pretty aweful too. So far for us Ulano 925 wr, if prepped right works good, Xenon Nova with Diazo is like steel, no hardener needed, or post exposing with the Nova, and we are now using Murikami Aquasol HVP with Diazo and it's got a really nice price point per gal, coats really really nice, holds up awesome on press for discharge or plasitsol printing, and exposes really fast for a Diazo emulsion. Chromoma blue was our favorite for plastisol, but we have been testing to get use into 1 emulsion shop wide, we are pretty sure the Murikami is the winner!
I've gone through a few gallons of the HVP and on this last one I put in the diazo to see how it affected the process. I'm sort of torn between hardener and no diazo and just putting in the diazo and dealing with longer exposure times.
Comparing time I'd lean toward the straight HVP with hardener being a little faster than HVP with diazo. I've found them bot pretty comparable in durability though.
I still like the HV blue and I feel like it held better detail straight out of the bucket compared to the pink, but that could just be in my head!
-
I hear ya Integrity, my friend Patrick Lashbrook that did all the production at Real Thread, all waterbased and discharge turned me on to the HVP. They do multi color discharge jobs, AOP discharge, huge runs using the HVP so for me they did the testing to see how it would hold up with w/b printing on their challenger 3. Actually the HVP without diazo will hold up for small wb orders like 25-50 pieces, maybe longer on a manual press, but on the auto they need to be hard, adding the diazo with only putting water in the diazo bottle 1/4 of the way up keeps the thickness of the emulsion and I can say it's rock hard and long lasting on press. Now that we have the I-Image CTS in action the exposure times are cut way down so it's very tolerable time wise in that aspect, but running the gambit of emulsions for discharge printing, my top two would be the HVP with diazo and the Xenon Nova with diazo. Thing with the HVP you can get it for about 50 bucks a gallon vs 88 for nova.
-
It can work but the best bet is to use products designed for this specific application. For instance CCI 25WR with hardenerX. Otherwise you're rolling the dice.
-
I hear ya Integrity, my friend Patrick Lashbrook that did all the production at Real Thread, all waterbased and discharge turned me on to the HVP. They do multi color discharge jobs, AOP discharge, huge runs using the HVP so for me they did the testing to see how it would hold up with w/b printing on their challenger 3. Actually the HVP without diazo will hold up for small wb orders like 25-50 pieces, maybe longer on a manual press, but on the auto they need to be hard, adding the diazo with only putting water in the diazo bottle 1/4 of the way up keeps the thickness of the emulsion and I can say it's rock hard and long lasting on press. Now that we have the I-Image CTS in action the exposure times are cut way down so it's very tolerable time wise in that aspect, but running the gambit of emulsions for discharge printing, my top two would be the HVP with diazo and the Xenon Nova with diazo. Thing with the HVP you can get it for about 50 bucks a gallon vs 88 for nova.
I have been running HVP consistently on 100-200 pc discharge runs with just hardener no diazzo without breakdown. I have ran as hi as 300 with out it and its been fine. Its all in that first exposure that seals the deal. If you do not nail that then you will have a problem. We also do not post expose. Just 1 and done.
-
what do you block out with if not post exposing?
Hvp is the only emulsion in my shop. Have diazo on hand but have never needed it. Everything J said above is correct in my experience- thorough exposure + hardener as needed.
-
750 pieces yesterday on Aquasol HV and hardener no diazo super fine detail no emulsion breakdown.
(on screens with really fine lines etc, that is typically the first area to degrade)
-
A timely thread! So are you guys going with no diazo just to shorten up exp. times?
-
Haven't needed it yet, and yes, after using photopolymer most of my career the exposure times for
anything with diazo are almost unbearable.
I am considering a switch though as I'd like to begin washing screens out in an area with a skylight.
-
we are using HVP without diazo on small discharge runs but we have also been trying CCI TX-Discharge, same price point as HVP but is sold locally. Adding the diazo is murder on expo time so we are trying to find a way around it when we can. This hardener you guys are using, what does it do to your reclaiming process? maybe adding time for exposure with diazo will save time on reclaiming with hardener? I have never used a hardener, maybe something else to try out after we are sick of the diazo. We went to a single point MH unit recently so dialing in our time is the issue at the moment.
-
Hardener adds a few minutes in the dip tank is all. I'm fine with that, we don't ever wait on the dip tank.
-
Yes, love dual cures but expo times keep them out of my shop.
I actually prefer reclaiming with hardener! You can leave the screens in the tank for as long as you like without the emulsion sloughing off.
Sent from my XT907 using Tapatalk 2
-
what do you block out with if not post exposing?
Hvp is the only emulsion in my shop. Have diazo on hand but have never needed it. Everything J said above is correct in my experience- thorough exposure + hardener as needed.
Just tape over them. Stop the squeegees from getting that high and they dont ever have an issue. Run all tape on the top.
-
Gary Fox told me his hardener will work on ANY emulsion for discharge. Will be trying that next week over a photopolymer.
-
what do you block out with if not post exposing?
Hvp is the only emulsion in my shop. Have diazo on hand but have never needed it. Everything J said above is correct in my experience- thorough exposure + hardener as needed.
Just tape over them. Stop the squeegees from getting that high and they dont ever have an issue. Run all tape on the top.
Ahh yes. This works if the rest of your screen is perfect but I really like using emulsion (dyed differently from the one you coat with) for the little pin holes. There's nothing worse than trying to fandangle a little pc of tape to the bottom of a WB/DC screen when it's loaded, nearly impossible.
My MO so far has been to use very thin reggies/no reggies on single color and not resolve them, emulsion blockout if needed for any resolved reggies, pinholes or along squeegee areas if a very long run, dry, post expose, harden if you want the extra insurance on runs over 200-300.
Is there a water resistant blockout pen out there that you could use pre-press and on press? I would love that. With something like that I could eliminate the post expose although I still think it helps strengthen when done properly.
-
I've heard of people using plain ol' fast drying nail polish for on-press block-out on WB/DC. I haven't tried it myself yet though...
-
Nail polish does work and it blows right out. Zoo we have very few pinholes if any most of the time. If we do than nail polish does the trick and dries fast.
-
Kiwo blue wb block out is awesome, dries fast and won't let loose in the run.
-
I had my co-worker bring in some nail polish she didn't want for this but was hesitant to try it for fear of it locking into the mesh- glad it doesn't!
I'll check out the Kiwo too.
-
Well, I feel dumb, they also make a water resistant blockout pen like - it's blue v. the green I use for plastisol. Doesn't look like any of them would totally work on press though.
-
I found the problem with the pen was it took too long to dry mid run. I never tried the nail polish, may be worth a shot.
I think I may try out some of the hardener on hvp and CCI without diazo and see what happens.
-
Gary Fox told me his hardener will work on ANY emulsion for discharge. Will be trying that next week over a photopolymer.
Did you try it? How were the results? I would love to keep 1 emulsion and just harden when needed.
Matt
-
Gary Fox told me his hardener will work on ANY emulsion for discharge. Will be trying that next week over a photopolymer.
Did you try it? How were the results? I would love to keep 1 emulsion and just harden when needed.
Matt
Totally agree, I am in the process of trying that and the new WR14. Will post results.
-
I would love to keep 1 emulsion and just harden when needed.
Aquasol HVP + Murakami Hardener MS
-
Well, I feel dumb, they also make a water resistant blockout pen like - it's blue v. the green I use for plastisol. Doesn't look like any of them would totally work on press though.
Can't beat a bottle of polish from target or the 99 cent store for.. .99 cents.
I've used the blue stuff.. works good but has a long dry time so be sure to apply it well before a run or it'll break down on press.
-
okay. I tried. I used ulano wr hardener on proclaim cl. That is a dual cure. I did 2 short runs with water base, not discharge. The runs were 1 color on 48 and 2 colors on 48. The screens held up fine. I used the same emulsion and post exposed in the sun before the hardener. It looked like the areas that I used emulsion as block out was beginning to break down though. I will try nail polish on the next run.
-
Remember to post expose after blockout and before hardener
-
Remember to post expose after blockout and before hardener
I left them in the sun for well over an hour to dry. I figured the FL could expose/post expose in just a few minutes.