What causes Discharge ink to fade on a shirt?

[ericheartsu]

This year i'm making it a personal goal to learn about inks and pigments.

One of the biggest thing I want to learn about and understand is the science in curing inks, and how the different inks and colors react with heat!

My first question is, what makes discharge ink fade on shirt over time? What can i do to ensure my prints won't fade after the first wash? First hand i've seen discharge prints with Reds or blues fade after a couple of washes, and I'd like to understand why, and if there is anything i can do to combat it!

[Colin]

Have you looped those shirts to check for fibrillation?

I was always told that ink penetration was a major culprit for looking washed out.  But I have also noticed fibrillation helps at least as much.

[Rob Coleman]

I am sure others will chime in, but I will give a perspective from a manufacturer point of view.  Note:  This may or may not be the case - certainly not implying.

One:  Not fully evacuating all the water in the ink film, thus not fully allowing the binders to crosslink.  Most H20 companies recommend 330F for two full minutes.  Forced hot air with good air flow.  If you cannot get this - then you need to add cross linker to allow for post curing.

Two:  The BINDER in the base is what BINDS the pigment.  Different manufacturers can have different levels of BINDER.  Overpigmenting the base can result in washout, as there is just not enough binder present to hold all the pigment.  This is why STRONG pigments are preferred - you can use less and stay within the threshold without adding additional binder.  Now if you are using pigments and base from the same manufacturer, AND staying within their recommendations, and fully exhausitng all the water during curing, and you are seeing this - then I would consult with them.

To see if indeed this is the case - you can add additional binder to your ink.  Use the standard formula as a control, then maybe add 10-20% additional binder.

Lastly, some people arbitrarily add water as a thinner - some reps even advise this.  Me - not so much.  Again, let's say you add 10% water, you are spreading the available binder over a much greater volume, thus reducing its ability to hold pigment.  A better method is to mix BINDER and water 50/50 and use that solution to reduce viscsity if needed.

Just my $0.02!   

[Screened Gear]

Rob good points. I like your mixing binder and water to thin out the inks. I have a bunch of binder that I don't use but I may just add that to my water just because it sounds smart.

[ericheartsu]

bumping this back up, so i can get some more insight!

[Orion]

If you have the ink penetration and your cure dialed in, I would start looking at testing different binders and using a fixer.

[brandon]

If you have the ink penetration and your cure dialed in, I would start looking at testing different binders and using a fixer.

That right there. Cure. Too many shops run the dryer too fast for this type of ink. Or run it through twice. Ugh

[Itsa Little CrOoked]

If you have the ink penetration and your cure dialed in, I would start looking at testing different binders and using a fixer.

That right there. Cure. Too many shops run the dryer too fast for this type of ink. Or run it through twice. Ugh

I've done two passes many times, Ugh is quite accurate.

But here is a question for you, Brandon (or anyone who knows). When necessary, do you think 2 passes through the tunnel works consistently, with no other downside except extra labor and utilities??

Some of our discharge jobs contain a foiled element.  I PURPOSEFULLY undercure those on the first pass through the tunnel, because I have a hard time getting 100.00% foil coverage otherwise. So we print, do a questionably quick cure, foil them, and down the tunnel again.

Stan

[ZooCity]

I agree that penetration and cure are the top two things that need to be addressed. 

We're lucky in that we not only get good to excellent penetration but have the ability to cure our inks for 1.5-2minutes at 350˚F with more than ample airflow.  It helps with troubleshooting immensely to just eliminate these two variables right out of the gates. 

Equally important is the fabric.  I have seen certain fabric look like total ass after 10+ washings and other look fantastic; same ink/cure/screen/etc. 

I think binder/pig ratio is the final frontier for our shop getting optimal wash results from DC and WB inks.  Where we have seen poor results and all other variables check out and it comes down to "what's wrong with this ink?" binder and/or any other chemical mechanisms to ensure the pigment affixes to the fibers seem to always pop up as the culprit.

In my opinion, inks should not be shipped without adequate binder and any other additives required for successful encapsulation of fibers by the pigment/base combination.  Given the long string of variables that an ink may encounter I think the best wb/dc ink would be maxed out with the highest quality, most aggressive binder to give you the best possible chance of encapsulating the garment fibers for the long haul.  Binder seems to be one of the more expensive ingredients in an ink.   I can see why manufacturers need to balance the binder level/quality with the price.

However, I do not like when someone sends us an RFU ink, we print it correctly, cure it to perfection and then it does not do well in long term wash testing.   Had this happen twice late in the year- one needed a fixative the other we are still waiting for an answer on but it's clear that ink did not contain adequate binder and it's pig just ultimately "let go" of the fabric after enough washing.  DC INKS ARE NOT ALL CREATED EQUALLY.  You may not always get what you pay for exactly, some are fantastic at a fair price, other lackluster and overpriced, but there is a difference in what is going into some of the cheap stuff v. the more expensive.  This will impact different shops differently however.  We use some very affordable components for our DC ink and also some spendy ones.

I love the idea of using a distilled water/binder mixture to maintain the balance of the ink Rob, great thought.  We don't use water here as a thinner too much, except to activate the ZFS, we put in about as much water as ZFS.  We do add water during those extreme dry times but this is just to combat all the evaporation going on on press.   We use penetrant, retarder and softener to make the ink flow the way we want.  The nomenclature of these additives can be confusion from brand to brand but they each have a special purpose, with the surfacting properties being our most needed it seems.

If you can't tell, this is a subject that is always on my mind.  I got us a usb microscope to help really lock in the last of our testing on these inks this year.  Considering where we are at as a shop with this, I think it's going to boil down to fabric and then correct/perfected balance of binder : base : pig.  I have done a little nerding out on this and, given the space would probably be making our own inks. 

[ZooCity]

If you have the ink penetration and your cure dialed in, I would start looking at testing different binders and using a fixer.

That right there. Cure. Too many shops run the dryer too fast for this type of ink. Or run it through twice. Ugh

I've done two passes many times, Ugh is quite accurate.

But here is a question for you, Brandon (or anyone who knows). When necessary, do you think 2 passes through the tunnel works consistently, with no other downside except extra labor and utilities??

Some of our discharge jobs contain a foiled element.  I PURPOSEFULLY undercure those on the first pass through the tunnel, because I have a hard time getting 100.00% foil coverage otherwise. So we print, do a questionably quick cure, foil them, and down the tunnel again.

Stan

No.  You can def get away with it where needed or even required as with your foil jobs but once the water is gone from the image area the DC process will be altered.  That's the main variable you'll be fighting.  Try misting the prints with distilled water before you run them back through, could make a world of difference.   If you are running them again right after exit this is probably ok though. 

[screenprintguy]

What we've learned in the past few years of discharge printing is that just because something, "discharges", doesn't mean that the pigment has been fulling cured or "fixed" to the fabric. Good penetration is a factor, but you can still have awesome penetration and an improper cure. I got into the habit of adding Matsui's Fixer N to every discharge or water based mix that we make. Folks will say that it's overkill but we never have a print fade. One of our customers that was the main customer demanding discharge printing from us from the get go still has original prints that we did from the start and the colors are just as vibrant as the first wash. Just to be clear on product, we prefer, CCI D-Base, I even use this with zero activator as a base for regular water based prints on light or white fabrics. CCI D-White, and the CCI mixing system for pigments. We always use the boost parameter. For US, the CCI works great, is reliable, no screen clogs, no boogering up on screens with wet on wet prints, no flashing needed in multi colored runs, great cost, and proven to us that the prints last. I use 3% activator when discharging, and add Matsui Fixer N 2%, and if it's a decent sized run, 2% of Matsui's Print Gen. We Never add water, but then again, we are pretty humid over here so maybe dryer climates, especially like Jon's need the water. Folks also say that all activators are the same, I beg to differ on that point, using several brands, the Image star, which I believe is CCI's is what we have the best outcome with. To us, this system has almost no sink during the run, even the activator has less stank to it than others, note that if you cover a discharge mix, and open the next day, it will stank, lol, but for what ever reason, during production, the stink is almost non existent, especially with decent ventilation. We liked the usability of Magna, but it stinks so bad, everyone here complained, and honestly it really bothered my sinuses, maybe the pine oil in it caused an allergic reaction with my allergies, but over all, the mix system that magna has is great, and the base is very thin and easy to work with, for me the smell didn't set well.---personal preference---. I've tried Rutland and Sericol, both good, but I end up back with CCI. I find the CCI product to have a better shelf life too. Sometimes we can go a month or two without a discharge order and then like now, 3 months in a row with a higher percentage of discharge orders. Just my 2 cents, if you are having fading issues, first make sure you have a good mesh count, my go to has become 225 S mesh for wb prints. Always make sure you are getting at least 2 closer to 3 minutes in the dryer to really fixx that pigment in the fabric, and worst case scenario, try some Fixer N in your mix, it's never let us down.

[ZooCity]

We tried a fixative thinking it would combat the issue of the fiber ends washing out, Rutland's Fiberlock.  Turns out that it actually makes the print worse to use fixative if your curing is already complete.  I never would have imagined that but Rutland tech explained it as a product only to be used where the cure cannot be done 100% right.

Fixer N must be different?  What's your curing setup?

[screenprintguy]

340 degrees speed setting 1 on the Heatwave dryer lol, that keeps them in the chamber for exactly 2mins 52 seconds. Same setting since we started doing discharge because we were initially instructed by a Matsui Rep that you need a solid 3 mins, CCI Rep confirmed the same info with their product when we switched. I know I can run things through faster and, "see"  a discharge, but we always want to be sure that pigment is cured in. I'm not sure of the fixer product you mentioned Zoo, but I know the Fixer N looks like skim milk. I also whip this stuff up with a drill and let sit for several minutes before getting it in the screens. I always have the indication that it looks ready when there are a bunch of little bubbles at the top of the mix. I don't know if any of this has any "actual" function, but, following these steps has never let us down. Different shops have different preferences. I know guys who soley use Sericol, right out of the bucket and love it and "say" they have no issues, but I've had a mutual customer give me shirts as a gift printed at the same shop that prints faded after a few washings. Could be not enough ink dug in there, could be needing fixer, I know their dryer would cure the bubonic plague so it couldn't be bad curing. It just confirmed to me to stick to what we are doing. Another thing brought to my attention two years ago is staying on top of your dryer's air flow. If things are dirty, flow isn't good enough it can have a bad affect on the initial cure. I'm not sure how true that is, but I just try to keep our blowers cleaned monthly to not run into any issues. What works for one shop may not work in another though. Like said before we are a high humidity area so the length of time in the oven makes all the difference to us.

[ericheartsu]

At your temp, and speed, do you ever see shrinkage in the shirt, or burns? Do you use the same settings for WB ink?

[screenprintguy]

The Heatwave is a gas dryer with convection air, not sure what to do if you have an electric dryer, I know if there isn't airflow you are kinda skating up a hill. With a gas dryer, I haven't seen a shirt, even poly "burn". Now shrinkage, there are some shirts that it's almost impossible to avoid that, like tri blends, freakin hate them especially when people want water based inks. For that, Green Galaxy makes some awesome inks that you can add their "warp drive" to, and cure them very fast at below 300 degrees. 340 "shouldn't cause a lot of shrinkage" if you temp test and see that your print is hovering at that 330-350 mark, if it rises up then you will probably see some shrinkage. We just ran a big batch of bellas and canvas, it was really humid today so we had the heat up in the dryer to 360, same speed, everything was nice. Dryer day I would have brought the heat down to 340. Really the battle is the time in the dryer. I only have 8 feet of heat in the Heatwave so it's not, "ideal" for w/b printing, you really want 12' for more, but I know that's not always an easy run to the store and buy a bigger dryer, so we just slooooowwwwwwwwwwwwww down, which sucks, but it's better than 500 fashion fit shirts with multi location printing coming back because the ink is washing out. That new Sprint 3000 is built with the WB printer in mind. When we were up at the plant for the tour we were shown how the design lends itself to forcing more of the hot air down and through the shirts to get the ideal cure of waterbased/discharge, and HSA inks, nice machine for sure, but until any of can get into one of those, slowing things down is the cure I guess.