TSB
screen printing => Waterbase and Discharge => Topic started by: Rockers on August 02, 2012, 10:33:29 PM
-
Wondering what the reason for this might be. Could it be that the discharge base is not fully cured?
We printed discharge base flashed it for a few seconds and then printed red QCM WOW bright red and QCM cotton white on top. Cured it for around 2 minutes at 170 degrees Celsius in our gas dryer. Test washed a couple of shirts with the result that you can peel of the white and red.
Will try send them through the dryer again and see what is happening.
-
I can't help I haven't done this yet. I did do a white discharge as a under base with no wash test problems a few months ago. I only had it in the dryer for 90 seconds and got it a little hotter than you did. I got it to about 350 degrees on the shirt surface about one foot inside the end of the chamber. (170 Celsius = 338 degrees Fahrenheit) I can't imagine that little bit of heat could matter.
I am interested in what others say here. I want to start doing discharge under bases soon.
-
Are you using white discharge as the underbase?
I've used 80/20 up to 70/30 discharge base to white discharge as underbases for plastisol with no issues
Alan told me if you use too much or full white discharge the plastisol won't stay.
Try 80/20 mostly base. This will also print into the shirt easier to get the plastisol to end up on top of the shirt a bit instead of just on top of the waterbase ink I think.
-
I did it just for some tests. I use discharge white (CCI D-white) for the underbase. I was surprised at how the top colors stayed. I know alot of guys say they will wash off. If I was to do this on a job I would use 80% base 20% white.
-
A straight discharge white base without some clear base added will crack and the top colors will flake off, maybe you want to print all discharge colors.
Darryl
-
A straight discharge white base without some clear base added will crack and the top colors will flake off, maybe you want to print all discharge colors.
Darryl
I have a sample on my desk and after 3 washings, still beautiful. So I guess its more of the application and alot of variables.
-
Jason your base didn't crack? my straight white discharge base cracks which cuz the top layers to crack as well, I was told to allways add some clearbase for that reason.
Darryl
-
A straight discharge white base without some clear base added will crack and the top colors will flake off, maybe you want to print all discharge colors.
Darryl
I have a sample on my desk and after 3 washings, still beautiful. So I guess its more of the application and alot of variables.
Bingo! application and variables.
-
the superhero job I posted on here, it has Sericol HO white base, and after 3 washings, I think it looks better than it did right off the press. And zero hand.
So this application, I KNOW works.
Sericol HO discharge white on a 200 mesh
CMYK 305 mesh
highlight white 230 mesh
Wash it and it looks GREAT!.
Oh yeah, Gildan 5000
-
Sounds good Jason. If a heavy mesh is used for an underbase and you get too thick of an ink deposit along with the deposit being driven completly to the inside of the shirt then there is going to be a problem with your over print plastisol inks
-
Wondering what the reason for this might be. Could it be that the discharge base is not fully cured?
We printed discharge base flashed it for a few seconds and then printed red QCM WOW bright red and QCM cotton white on top. Cured it for around 2 minutes at 170 degrees Celsius in our gas dryer. Test washed a couple of shirts with the result that you can peel of the white and red.
Will try send them through the dryer again and see what is happening.
Today was my first attempt at a discharge underbase and plastisol top. I used 50% base and 50 % white discharge that I purchased from Ryonet. After one washing no problem so far. I loved the fact that it worked without a flash. I was really nervous about the plastisol on top as far as curing was concerned thinking that I'd have to run a higher temp. I have a mini sprint and set it for 90 seconds travel and 360 degrees and that seems to do it. 170 degrees celsius equals 274 degrees farenheit. I might be wrong, but I'm pretty sure that's not hot enough.
-
Well we used Sericol Texcharge for the underbase. Clear mixed with some white texcharge. The recommended curing temp. by Sericol is 160 degress Celsius for 2 minutes minimum. it was
printed through a 166 mesh. But maybe I have to raise the temperature considering there is a layer of plastisol on top of the discharge. My only worry would be to over cure the plastisol ink.
-
170C = 338F
-
170C = 338F
Right on.
274F=134 C= totally under cured.
But as I have said they went through at 338F for 2 minutes.
-
Well we used Sericol Texcharge for the underbase. Clear mixed with some white texcharge. The recommended curing temp. by Sericol is 160 degress Celsius for 2 minutes minimum. it was
printed through a 166 mesh. But maybe I have to raise the temperature considering there is a layer of plastisol on top of the discharge. My only worry would be to over cure the plastisol ink.
I told you I may be wrong :'(. I'll have to try the Sericol then, I didn't know that it would cure at such a low temp. I was nervous myself today because I'd printed discharge before, but never with plastisol on top. I was able to keep the temp and the time the same and with no flash. Was that Sericol a premixed 100% white discharge or did you mix with clear base?
-
Clear with some white, but I might have added too much white.
-
170C = 338F
Right on.
274F=134 C= totally under cured.
But as I have said they went through at 338F for 2 minutes.
Sorry, Google search done it to me. On the temp info.
-
[hijack]Awesome, free conversion program (http://joshmadison.com/convert-for-windows) for almost any units that I've installed on almost every computer I use.[/hijack]
-
170C = 338F
Right on.
274F=134 C= totally under cured.
But as I have said they went through at 338F for 2 minutes.
Sorry, Google search done it to me. On the temp info.
What sort of emulsion do you use for your discharge work? We used to use Sericol 916 but i will now change to Ulano QT discharge.
-
I used Ryonet WBP Hybrid emulsion. It doesn't seem to have the solids of some others I've used. For this job, I coated 2/1 so there wasn't alot of EOM. I always post expose for discharge and use harden x. With the Harden x, I've had it hold up for a 900 piece job.
-
I used Ryonet WBP Hybrid emulsion. It doesn't seem to have the solids of some others I've used. For this job, I coated 2/1 so there wasn't alot of EOM. I always post expose for discharge and use harden x. With the Harden x, I've had it hold up for a 900 piece job.
Got a pot of WBP here but no harden x. Does adding the harden x make it a lot harder to reclaim the screen?
-
Answer.. the plastisol wasn't cured completely. Needs to stay in the heat longer or you need to flash the base before the colors.
When using a waterbase underbase and plastisol colors, the underbase cures first by steaming off the water, only then will the plastisol start to cure. This plastisol under-cure tends to happen more when people do a true WOW print with no flashing of the discharge base first. If you flash the base until you can start to barely see the design on the shirt, then print your colors, you'll find the shirt won't need to stay in the dryer so long.
-
Answer.. the plastisol wasn't cured completely. Needs to stay in the heat longer or you need to flash the base before the colors.
When using a waterbase underbase and plastisol colors, the underbase cures first by steaming off the water, only then will the plastisol start to cure. This plastisol under-cure tends to happen more when people do a true WOW print with no flashing of the discharge base first. If you flash the base until you can start to barely see the design on the shirt, then print your colors, you'll find the shirt won't need to stay in the dryer so long.
agreed 100% and it prints easier with the flash IMO.
-
I used Ryonet WBP Hybrid emulsion. It doesn't seem to have the solids of some others I've used. For this job, I coated 2/1 so there wasn't alot of EOM. I always post expose for discharge and use harden x. With the Harden x, I've had it hold up for a 900 piece job.
Got a pot of WBP here but no harden x. Does adding the harden x make it a lot harder to reclaim the screen?
Slightly harder to reclaim with the harden x but not too bad. If I've used harden x, I'll leave them in the dip tank for around 3 minutes longer then the screens without. By the way, I won't use the harden x for 100 pc jobs or less. The only reason I purchased a hardener was because I had a 5 color straight discharge job start breaking down on me at around 150 pieces. They may have lasted longer but I didn't post expose that job so I can't blame the emulsion. I was new to discharge and taught myself a painful but valuable lesson.
-
I used CCI D White as my underbase, no mixture, straight white, no flash on a few and flashed a few, then red plastisol on top. Even before I washed it I knew it wasn't going to work. It was very brittle and flakey, the prints without the top red were fine, it was just the combination of the discharge white and plastisol that didn't mix well. I haven't cut it down to an 80/20 mix yet but maybe when things slow down a bit I can experiment.
So there are a few here that have gotten good results with straight discharge white and plastisol on top but more of us that it didn't work right? I've never had problems with discharge base, no pigment, as an UB and plastisol on top.
-
for a white base using discharge white only -we needed to flash then we are ok to run anything on top, plastisol or Wb.
For a discharge base, no flash, WOW plastisol, we needed to do an 80/20 mix. this combo works great for us, so far.