Author Topic: Jumping in to Waterbase and Discharge realm. Need help please.  (Read 3067 times)

Offline inkstain

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Jumping in to Waterbase and Discharge realm. Need help please.
« on: January 12, 2014, 12:55:12 PM »
Hi guys,
I want to start providing waterbase and discharge for my clients as they have been asking.
I'm using R2O waterbase which I believe is matsui and magna super white discharge.

I live in Hawaii which is very humid.  Does that help with waterbase and discharge not drying out in the screens much?
I tried a waterbase print recently on white shirts.  It was a 2-color, black and red.  Put it through my dryer at a much slower speed and dropped the temp down some.
I have an electric dryer that has about a 5ft chamber I believe.  Supposedly it has the forced air. But wonder really if it works.  I put a little fan a little ways from the entrance of the dryer on low and tried to get a little more air flowing to evaporate the water.  I took some shirts home and put them through a wash.  Uggh!  Both colors of the design stayed on but the whole shirt turned light pink.  I'm guessing the red wasn't totally cured.  Not enough cure time.  So hard to know.  From what I remember my cure time was about 60 secs.  Is there a way to tell if the ink is cured without washing it?  Probably best was is to test wash right?

Another thing:  Emulsion for waterbase and discharge.
I've been using murakami hvp photo cure emulsion.  Works great with plastisol.  I talked with murakami and they mentioned I could still use it but add diazo to it.
Then take my exposure time up some.  Excited to try that out.  Cause I could tell that my emulsion was breaking down some.  Anyone out there use hvp and diazo?
I just want to have a screen that holds up without stressing middle way through a job.  My job counts are in the 36-200 realm. 

Whats a good retarder for waterbase and discharge out there?

Sorry for the rambling.  Still early here and brain is a bit foggy.
Any tips or help would be much appreciated!
Aloha!



Offline TCT

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #1 on: January 12, 2014, 01:15:07 PM »
The humidity definitely helps. I was in Portugal a short while ago and all they printed was WB. Two of the places had "water spritser " one was a modified shoot out gun with two actuators so it would pivot and spray intermittently. Pretty sweet!

We use the HPV as well with no diazo, we used diazo once but it was not a huge help. The key is to let the screen dry all way(we usually go at least over night in front of the dehumidifier)  before you print. Then post expose after it is all the way dry(we screwed that up for a while). This should hold you for print runs under 500, over 500 we spray on MS hardner.
Alex

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Offline tpitman

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #2 on: January 12, 2014, 02:11:01 PM »
What waterbased I do is through a dryer about the size of yours. Raise the doors on the ends (if you have them) to assist in water evaporation, and slow the dryer down so the shirt stays in the chamber for at least 90 seconds at 320 or so. Small dryers make it a bit more difficult but not impossible, especially with larger prints and a long run. Things like upper left chest prints move along pretty quickly.
Do some test prints and wash tests to get the cure times down. I've been trying to work more waterbased into my stuff because it makes such a nice print.
Work is the curse of the drinking class . . .

Offline inkstain

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #3 on: January 12, 2014, 06:40:33 PM »
The humidity definitely helps. I was in Portugal a short while ago and all they printed was WB. Two of the places had "water spritser " one was a modified shoot out gun with two actuators so it would pivot and spray intermittently. Pretty sweet!

We use the HPV as well with no diazo, we used diazo once but it was not a huge help. The key is to let the screen dry all way(we usually go at least over night in front of the dehumidifier)  before you print. Then post expose after it is all the way dry(we screwed that up for a while). This should hold you for print runs under 500, over 500 we spray on MS hardner.

Thanks for the info.  Would you expose the screen then dry it over night in front of a dehumidifier?
I'm gonna try a quart size of HVP with diazo to see if it helps.
It's just so new to me, printing waterbase. 

Offline inkstain

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #4 on: January 12, 2014, 06:45:28 PM »
What waterbased I do is through a dryer about the size of yours. Raise the doors on the ends (if you have them) to assist in water evaporation, and slow the dryer down so the shirt stays in the chamber for at least 90 seconds at 320 or so. Small dryers make it a bit more difficult but not impossible, especially with larger prints and a long run. Things like upper left chest prints move along pretty quickly.
Do some test prints and wash tests to get the cure times down. I've been trying to work more waterbased into my stuff because it makes such a nice print.
Thanks!  Yeah, I have doors on each end and will open them up more.  From the sounds of it I have to cure them longer.  The thing that was tuff with this print is that it's like 15" wide by 17" tall.  Remember the RUN DMC logo?  Super similar but with different letters.  Lot of ink.

With that sorta a print size, production is so slow which can cause the waterbase inks to dry up in the screens.  So it's a challenge to make sure screens are all good and holding up.

Do you think if I were to put the shirts through the dryer twice that would help cure?  Sounds like it would. 
Thanks again for the help.

Offline TCT

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #5 on: January 12, 2014, 06:53:33 PM »
We just have a large commercial dehumidifier in our basement that runs 24/7 so we have our screen drying racks over in front of it anyway. The dehumidifier may not be necessary for everyone.
Alex

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Offline starchild

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #6 on: January 12, 2014, 07:23:18 PM »
You mentioned that you had a fan at belt height.. Was the dryer temp. adjusted to compensate for the cooler air that is being drawn into the chamber? What is your exit temp?

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Offline mimosatexas

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #7 on: January 12, 2014, 08:46:22 PM »
Don't turn your dryer temp down, heat still helps with the curing in addition to longer dwell.  The fan at the entrance will bring the temp down a bit on its own but will also help with the curing.  Your shirt shouldnt be turning pink.  I would suggest adding matsui fixer and testing your pigment load so it isnt bleeding or dulling, but you are still getting vibrant color.

Offline jvanick

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #8 on: January 12, 2014, 08:49:59 PM »
The r2o inks take a long time to cure.  Id run them through the dryer at least 2 times.  Also.. make sure the ink is getting up to at least 350 degrees at final cure... 

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Offline Inkworks

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #9 on: January 12, 2014, 09:28:59 PM »
No way would I be blowing air into a small dryer. you'll likely just be blowing the heat out of the tunnel.
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Offline abchung

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #10 on: January 12, 2014, 09:46:56 PM »
Humidity is great for the screen, but not for drying.

Try to do some testing. We have to add an extra minute for our drying when it rains.

If you do dry it for a long period of time at 160C, do a stretch test on the fabric, because our thin cotton tear if we dry it for too long at 160C.

Offline starchild

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #11 on: January 12, 2014, 10:24:02 PM »
No way would I be blowing air into a small dryer. you'll likely just be blowing the heat out of the tunnel.

I think using a fan to move the "clouds" through a short chamber is ideal..(Water vapor never increases becauce it's only one print at a time in the chamber and the air from the fan should quickly move it to the exit.) But it should be one/two of those computer casing type fans and the heat needs to be increased to compensate for the cool air coming in or heat the air before it enters the chamber..

Hmm.. Eureka!

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Offline Inkworks

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #12 on: January 12, 2014, 11:24:35 PM »
Only if your small dryer can keep up with the heat being blown out of it and sustain good tunnel temps, which, i.m.o. most small ovens can't. Take a IR temp gun and take readings with and without the fan if you want.
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Offline starchild

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #13 on: January 13, 2014, 10:07:57 AM »
This conversation made me think about the folded horn speaker box.. My Eureka..



Instead of the fans mounted foward facing like the pic shows, it's mounted from the top and draws air into it which is heated by an element and out through the scoop into the chamber flowing parallel to the belt.. The box itself would be about 12" tall to contain fans and element but as wide as the belt of the dryer it's mounted on and be able to be raised and adjusted just like the gates on some dryers.

The reason shirts smoke exiting the dryer is because the water vapors are stuck inside the dryer just hanging around until it hits the cool air on exit and forms clouds (that alone is not a good sign of proper efficient drying) and if you have the forced air versions that blows the air downward it's even worst.

I think the vapors in the chamber should be escorted to the nearest exit before even getting to heavy/condensed.

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Offline inkstain

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Re: Jumping in to Waterbase and Discharge realm. Need help please.
« Reply #14 on: January 13, 2014, 12:37:28 PM »
Thank you everyone for all the good insight!!
I appreciate it a bunch.
Looking forward to try and figure it all out in my situation.
I know I need to slow down the belt and possibly put the shirts through twice which I know will slow production.
But better a cured shirt then not for my clients.

Aloha