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screen printing => Waterbase and Discharge => Topic started by: 1984solar on March 18, 2019, 10:07:40 PM
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If the Ink is fully bright is the ink fully cured? printing green discharge on black it was totally opaque running through the dryer at 40 secs. I wasnt sure so I upped the time to make sure it was fully cured and that slowed production for the job. Would have been awesome to run the job with the shirts being in the chamber for 40 secs and they looked exactly the same but i didnt do it just in case
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40 seconds? My money is on not cured at all. Try more like 2 minutes or longer. Also better to bake a cake slowly than rush it as Rick Roth would say. Might hold up for several washes or even more but over time the print will wash out if not cured correctly. Just because it "discharged" doesn't mean it actually is completely in the shirt
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Exactly what Brandon said.
Discharging of the garment actually happens at a lower temperature than curing the ink deposit. And it happens faster.
So never use the color change factor as an indicator of cure.
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Do a wash test.. Different dryers and different shop conditions all contribute as do dryer temp and retention time in the chamber. Its all relative. I have done manydischarge prints that were fine in the 45-50 second range that washed just fine. Although the above statements apply as a general rule for discharge printing. This is screen printing and 100 variables are involved. mesh, squeegie, deposit,additives, humidity,dryer type, ink brand, how much water did youi add.. DO A WASH TEST!!
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What type of dryer?
Our retention time for water based ink is 80-90 seconds, but we also add a fixer (one that doesn't give the ink a short lifespan though) to help. This is with a large gas dryer.
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What type of dryer?
Our retention time for water based ink is 80-90 seconds, but we also add a fixer (one that doesn't give the ink a short lifespan though) to help. This is with a large gas dryer.
What fixer are you using that doesn't add a shelf life? Been looking for one!
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I always wonder about this...
Discharge starts to bleach under a flash for a few seconds... Even running through a dryer at 40 seconds, will fully lighten the fabric. ( It doesn't get any brighter the longer it stays in there) So in theory... And this is purely out of speculation.... Putting a plastisol that cures at 320, immediately after reaching 320 degrees on top.... SHOULD in theory.... last "forever"... Correct? You may not be fully "curing" the discharge.... but the plastisol would have formed a mechanical bond with the fibres, and cured properly is very long lasting. Right?!
This is my thought process... Even a discharge that is not cured fully, will bleach the fabric, and create a good base for the plastisol on top.... Its not like the discharge is going to re dye the fabric after 10 washes.... This all being said we retain the discharge and plastosil in the dryer at 350 for around 100 seconds and our wash testing is great... BUT , I always think about it haha
This does not apply to a discharge colour ( or plasticharge) , this is meant for DC base with a plastisol on top...
thoughts?
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Depend son the discharge you are using.
If it has binders in it, that needs to cure for proper long lasting ink adhesion.
If that ink has no binders, like using plascharge as an underbase (there are several products like this on the market and more are coming), then you do not need to reach "cure temp" for that, since there is nothing to cure.