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White Ink washing out.

Posted: Sun Feb 25, 2007 9:40 am
by djoakes
I am encountering problems with white ink on black garments. The customer did not want to pay for a flash and overprint so I double hit the images wet on wet and sent the garments through my dryer as usual.

This is the second time I have reprinted this job having to replace over $400. worth of garments the first time. The images are washing out of the clothes. If you take the image area and pull it with both hands, it will break apart. The first time I thought I forgot to change my dryer setting from 220 after running transfers. But the second time I most definately had my temp. at 325 when I ran the job.

Do I have bad ink or is there something I'm don't know about?

Thank you.

Posted: Mon Feb 26, 2007 12:34 pm
by yaleteamsandtees
Sounds to me like you're way under cured.

Having the dryer set to 325* doesn't mean the ink film
will reach that temp in the time it takes to pass through the dyer.

What machine are you using?
Does it measure the chamber temp or the element temp?

Our Chaparral measures element temp and we have it set
@ 850*.

Do you have a non contact therm?

After being burned the first time
I'd have bought one the very next day.

Posted: Mon Feb 26, 2007 4:02 pm
by d fleming
If the customer refused to pay to have it printed using the proper method, you should have refused the job. ( I'm sorry Sir/Madam, but that is what it takes to do what you ask correctly, perhaps a light colored shirt would fit your budget better?) Would have saved you having to reprint it and lost$$$, time and reputation. Now you have a customer who will tell anyone for the next few weeks that you can't print on black all for the simple reason that this customer wouldn't pay the right price for the work requested. If you simply had to take the job for whatever reason, maybe you should have printed it using the correct method the first time and saved yourself some headache. The price is the price. Stick to your guns!

Posted: Mon Feb 26, 2007 4:13 pm
by yaleteamsandtees
Depending on the detail in the art
I can print a white on dark with a 110 double hit
no flash using Union's Diamond white on cottons.

The washing out problem is purely a result of under curing.

A flashed and hit print that is under cured will fare no better.

If it cracks when stretched, it hasn't seen enough heat to
fully cure and obtain the proper film strength.

And yes, I WILL tell the customer that if I deem it necessary.

Sometimes the flash can turn into a crutch.
(But, God, how did we live without them!! :wink: )

Take a shirt, print it again and turn the dryer up to 450.
Run it through at the same belt speed you normally would.

Let it cool and stretch it.

Now go and wash it.

I think you'll find your answer.

White Ink Washing Out

Posted: Tue Feb 27, 2007 7:10 am
by djoakes
Thank you for your help!!

With the printed garments that have been returned, can I re-run them through the dryer at a higher temp setting and finish the curing process?

Posted: Tue Feb 27, 2007 9:10 am
by yaleteamsandtees
If they have been washed, probably not but give it a try anyway.

If they have been cracked from being stretched,
you can cure the ink but it won't heal the cracks. :cry:

The rest can absolutely be run through again.
(And wash test one yourself before sending them out again)

Sounds like it's time for some late night quality control.

Posted: Wed Feb 28, 2007 10:45 am
by ROADSIDE
I had a nightmare job like that once. Now I run my dryer at 375 and I have NO PROBLEMS.

What kind of dryer do you have? Gas or Electric? how long?

Posted: Thu Mar 01, 2007 9:31 am
by X_Autotype_#1
The plastisol ink layer needs to achieve an ink-layer temperature of 350 F to cure. Regardless of the "temperature setting" of your dryer, the ink film will not crosslink or "cure" or "dry" until the the ink-layer reaches the required temperature. Check with your ink specs before starting the print run.

What that means is that if you have an under print white layer that has been printed and flashed, or printed wet-on-wet, you need to account for the entire ink film layer on the substrate, and ensure the entire layer of plastisol is crosslinked by attaining the cure temperature. You usually can't determine the actual ink film temperature by simply dialing in a setting on your dryer. That will always be a hit-and-miss determination, and with the cost of shirts and rejected product, you may not want to leave this issue to chance. Ink manufacturers try to build in as much latitude as they can for their inks, and ink color (as well as thickness) does also play a roll in cure time. Regardless, the nature of plastisol is that the ink layer must attain the specified heat temperature before the product will cure. Anything less is called "under cure" anything more is called "over cure". Each term represents it's own set of problems which usually results in under-performance of the product, which could mean REJECT to you.

I would recommend that you get hold of a package of heat sensitive temperature strips that can help you nail down the actual temperature that your ink is exposed to when moving through the dryer. The test strips are placed on the conveyer (or on a shirt) and pass through the dryer. Once through the dryer they have a color indication on the strip that tells you pretty accurately what temperatures have been reached during the heat pass. You can make simple adjustments based on this information, such as conveyor speed determined by the total thickness of the ink layer. The also make an expensive electronic devise that many sales reps can bring to your shop to test your cure, if you promise to make them happy by buying loads of ink from them. Heat temperature guns that sense thermal temperature also help, but cannot accurately determine the ink film layer temperature of the print, especially considering the speed of the conveyor and the impact of time exposure to the heat elements.

Take a look at the test strips offered on this web site for example:

http://www.jesseheap.com/Pictures/Fusin ... eaner.html

There's a good chance that your ink supplier can supply you with a small package of these strips in varying heat sensitivity ranges.

Screen printing is all about control of the variables, and everywhere you turn there's another variable to control. Your best chance for success is to get a good grip on as many of the controllable variables that you can cost effectively control. In the long run, it will save you time and money.

Best of luck!

Posted: Thu Mar 01, 2007 1:26 pm
by ROADSIDE
temp strips in my opinion are a waste of time and money.

$60 get you a laser temp gun that works like a CHARM. I got mine from FELLERS
aim it at the belt as your shirts are coming back and hit ink with the beam.

Also great for setting flash time.

I dont really have a problem with heavy ink deposits anymore

Re: White Ink washing out.

Posted: Wed Mar 06, 2013 8:45 pm
by the Art of Tees
I am confused about the temperature some people tell you 325, some 375 degrees, which one is the correct temperature?