# ink washing out



## cornerstone t's (Oct 17, 2009)

have been printing white on black, curing as we go and then running the shirt through a dryer at +350 white is washing out after one wash. what's going on?


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## jmlampert23 (Nov 7, 2008)

you are not curing correctly. it needs to cure above 315 for about 20 seconds. slow the dryer belt down


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## Pwear (Mar 7, 2008)

Make sure the ink itself is reaching 320+, not just the heater.


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## BillyV (May 8, 2009)

For best results use a temperature gun to make sure your ink is getting to at least 320


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## studog79 (Jul 13, 2006)

cornerstone t's said:


> have been printing white on black, curing as we go and then running the shirt through a dryer at +350 white is washing out after one wash. what's going on?


What do you mean cure as we go???? Are you p/f/p? If yes then you are fully curing during the flash instead of partial before your second print.


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## ErinAllen (Aug 11, 2009)

Hello!!

If your ink is washing out or cracking you are undercuring! Make sure that the entire ink film is reaching 320 degrees F. The entire ink film, not just the top of it or the garment around it. 

I do give you praise for wash testing. 

The best method of curing is through a belt dryer! A heat gun can work, but it only give you the temperature of the top of the ink film. A thermoprobe is a great tool to use. 
Good luck and have a great day! 

Erin Allen


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## JeridHill (Feb 8, 2006)

jmlampert23 said:


> you are not curing correctly. it needs to cure above 315 for about 20 seconds. slow the dryer belt down


This would be overkill and could cause more problems for you. Various inks require various temperatures. The majority of plastisol inks reach a full cure at 320˚F. It doesn't matter if it takes 1 second or 1 minute to reach that temperature. As soon as the INK hits 320˚F it's cured. That being said, a thick deposit of white ink takes longer because you are trying to cure the ink from top to bottom. Some people will place a heat strip underneath the print on the inside of the shirt and others will lower their dwell time until the ink reaches 330˚-340˚. Whatever method you choose, the wash test is the most effective test for confirming you have a properly cured shirt.

Even shirt colors will absorb or reflect heat more or less, so what works for a black shirt may not necessarily work for a white shirt. If you build a chart for cure times based on what type of shirt and what color, you won't ever have to second guess yourself again....


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## jim.goodwin (Jul 8, 2008)

JeridHill said:


> The majority of plastisol inks reach a full cure at 320˚F. It doesn't matter if it takes 1 second or 1 minute to reach that temperature. As soon as the INK hits 320˚F it's cured...


Jerid, I have heard this both ways, many times from professional screen printers. I've heard "get it to 320", and I've heard "keep it at 320 for..." Do you have a source for this information? I guess I could give my ink manufacturer a call to find out what they say but I thought others might benefit from hearing a definitive answer as well.


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## JeridHill (Feb 8, 2006)

You could be confusing plastisol inks with waterbased. For waterbased inks, you are trying to evaporate the moisture for the cure. So you would typically run the shirt through a long tunnel dryer at a slower speed (usually around 2 minutes) at a lower temperature.

Plastisols are made up of PVC resin, plasticizer and pigments. When the PVC resin heats up, they swell and absorb the plasticizer. This combination is what gives you the washability in screen printing. After an extended period of time of heat, it begins to break down this bond. So it doesn't matter how much time is needed to expand the PVC resin, once it does, it absorbs the plasticizer.


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## jmlampert23 (Nov 7, 2008)

listen you need to get the ink to 320 and let it dwell there for about 15 seconds. i can get it to 320 instantly but that does not mean it cures.


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## JeridHill (Feb 8, 2006)

jmlampert23 said:


> listen you need to get the ink to 320 and let it dwell there for about 15 seconds. i can get it to 320 instantly but that does not mean it cures.


Not trying to be argumentative, but this information is just wrong. Find a documented article to back up your advice and I'll change mine. Do a search on the internet and you will find tons of information to back up what I'm saying. It's simple chemistry....

If you overcure your ink, you can have just as bad results as if you undercured it. I'm trying to help, not hinder. Once your ink reaches 320˚(or whatever is recommended by the ink manufacturer for that specific ink), it is cured.


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## RichardGreaves (Nov 7, 2006)

I _am_ ready to argue, or most certainly pontificate.

Anyone that means well and wants to help out by telling you how long - is _guessing_. 

Invisible infra-red energy - heat (a variable), has to move through the air (a variable), then *through* the entire ink film (a variable), to finally raise the ink temperature up to the mfg. specification. The moisture in the cotton of the shirt is cooling the process as it evaporates and the first shirt down the belt is different from the 30th shirt at the end of a crowded belt. Combine that with thick or thin dark shirts and light reflecting thick white ink and you have the equilivent of a turkey compared to a chicken in the oven. 

I know you are in a hurry, but white ink filled with fillers & spacers takes a long time to heat up.

The proof is in the ink - it didn't survive the wash. Not enough heat to cure the ink - NOT high enough temperature perhaps, but more importantly, not enough VOLUME of heat to finish the job.

You can't _over cure_ textile ink, but you can overheat it. 270F is not enough heat even after 25 minutes. 400F wastes heat and even cotton dye colors will discolor white ink. 452F and the shirt will start to burn.

But you could cure the shirt for 60+ minutes at 320F and you only waste time and electricity. When you Boil an egg or cure Jello in the refrigerator, how long can you boil or chill it. When there is no more physical change, what's the point?

How are you measuring that the shirt & ink got to 3??F ?? If you aren't measuring, I can see why you are confused.

_from the Printwear Show in Charlotte_
_Richard Greaves 646-294-2799_


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## JeridHill (Feb 8, 2006)

Richard, Although I'd agree with what you are saying, if you have a shirt sitting at 320˚, it's impossible to have it stay at 320˚ for an extended period of time, unless your heat source is a low and the temperature is brought up to 320˚. Most dryers I know are well over 500˚ in order for the ink to reach the number needed. So even though what you are saying is correct about it staying at 320˚, in all likely purposes, it won't stay at 320˚ if you let it set for 15 seconds or 60+ minutes because the drying units are rated at much higher temperatures.

The premise still stands, once the reaction needed for the PVC to melt and absorb the plasticizer, it's finished. As for overcuring, I've read it and talked to ink manufacturers about it. It could be they were talking about specific types of inks, but over curing is possible and should be avoided. It makes it more brittle and easier to crack. It won't necessarily wash off, as it would crack.


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## Pwear (Mar 7, 2008)

jmlampert23 said:


> listen you need to get the ink to 320 and let it dwell there for about 15 seconds. i can get it to 320 instantly but that does not mean it cures.


Yes actually, it does. The chemical reaction that occurs when the ink cures, occurs at 320 degrees (or so, depending on the ink). Once it reaches that temperature through and through, the ink is cured. Leaving it there for 10 extra seconds is not going to cure it more.


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## RichardGreaves (Nov 7, 2006)

JeridHill said:


> Richard, Although I'd agree with what you are saying, if you have a shirt sitting at 320˚, it's impossible to have it stay at 320˚ for an extended period of time, unless your heat source is a low and the temperature is brought up to.


To abstractly explain ink cure, I am stating 'principles' to cement rules in peoples minds - especially when they are not measuring the shirt temperature as the ink cures.

If I calibrate my oven or dryer to heat the printed shirt to a maximum of 320˚F I don't understand how it is _impossible_ to sustain that temperature. 

If you calibrate your oven or dryer to heat the cabinet so shirts can go to 500˚F, you have to become an expert at timing exactly how long you can afford to allow the shirt to stay in the cabinet, before the shirt starts to smoke & burn.



JeridHill said:


> Most dryers I know are well over in order for the ink to reach the number needed.
> 
> So even though what you are saying is correct about it staying at 320˚, in all likely purposes, it won't stay at 320˚ if you let it set for 15 seconds or 60+ minutes because the drying units are rated at much higher temperatures.
> 
> ...


My point is that using high heat is tricky because you can damage the print if you expose the shirt too long. You can hurt yourself with a chain saw if you keep cutting down toward youronce the log is cut in two. 

If you over heat the shirt because you're in a hurry or your budget made you buy an oven that wasn't good enough to handle as many shirts per hour as you would like I understand how you think my abstract principles about PVC resin inks are impossible.

And yes, I do admit that there are many plastisols that will discolor (turn brown) & brittle, after 10 or 20 minutes at only 320F, but there are many that won't react and get brittle with long cure times.


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## tlbays (Apr 9, 2008)

Hi all

I'm relatively new to these boards, but I've noticed that many posters use a surprising variety of heat sources and methods to cure shirts.
Screen policing this variable and its variables will make a respondent dizzy without a complete laundry list of all aspects of their "curing system".

Speaking of laundry lists, I couldn't help notice Erin commending Cornerstone's wash test.

Despite the import of theory, even Union Ink suggests it as the ultimate verfication, regardless of controls even they put forth:

(Reprinted from the "Article" section of their website; courtesy of Union Ink Company) 

*Important Curing Tips*

White ink requires the longest cure time of any standard color. Light ink colors require longer curing periods than dark colors. Thick ink layers require longer curing periods than thin layers.
Glitter, shimmer, reflectivem, and metallic inks require longer curing periods because the pigments used in these inks tend to reflect infrared radiation (heat).
Prints (both on paper and garments) should be cured within a minute of printing. If you delay curing, the plasticizer in the ink may start to leach out of the ink into the substrate. This will look like an oily margin around the print.
Temperature tapes are not exact. They can vary as much as 10-20º F (5-10º C) and should be used only as a guide. The definitive test is how well the print launders.
Dryer temperatures can vary greatly with just minor changes in belt speed, garment loading, room temperature, air movement, or fluctuations in incoming voltage.
Happy trails!


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## JeridHill (Feb 8, 2006)

RichardGreaves said:


> If I calibrate my oven or dryer to heat the printed shirt to a maximum of 320˚F I don't understand how it is _impossible_ to sustain that temperature.


I believe I was speaking more of off the shelf flash units and dryers where people buy them, install them, use them. Never calibrating.

Obviously if you calibrate it to 320˚ and never more, then it can't go higher than the heat set. That being said, I know of so many screen printers that are using a flash unit to cure their shirts. I don't recommend that, but if someone is on a budget, then do it on a cart away from the press. To my knowledge, most flash units can't be calibrated (at least easily) to maintain a certain heat limit. Maybe they can, I don't know for sure. If so, then I believe it should come standard as a feature.


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## jmlampert23 (Nov 7, 2008)

Pwear said:


> Yes actually, it does. The chemical reaction that occurs when the ink cures, occurs at 320 degrees (or so, depending on the ink). Once it reaches that temperature through and through, the ink is cured. Leaving it there for 10 extra seconds is not going to cure it more.


 
that is 100% true but you are not going to get it up to 320 all the way through the ink with out letting it dwell in the dryer for a little bit of time. that is why you have a dryer belt with a speed control


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## JeridHill (Feb 8, 2006)

jmlampert23 said:


> that is 100% true but you are not going to get it up to 320 all the way through the ink with out letting it dwell in the dryer for a little bit of time. that is why you have a dryer belt with a speed control


This is true with white ink more so because it's thicker. If you are printing basic prints, the ink isn't thick enough to worry about it. But white ink, to get a good lay down, you flash and print over top of the ink. The more layers of ink you have, this is more of an issue.


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## Pwear (Mar 7, 2008)

jmlampert23 said:


> that is 100% true but you are not going to get it up to 320 all the way through the ink with out letting it dwell in the dryer for a little bit of time. that is why you have a dryer belt with a speed control


True, true.


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