[jdp1024]

Hello,
This is my first post as a member of Tshirt Forums. I have come to this site a lot when I first started screen printing and the members here have been VERY HELPFUL! Any questions I have I was able to find them here. But my recent screen printing job got me stumped and I don't see any answers here.

I've never had a problem printing White ink except this time around. After a few passes with the White ink, the ink turns black, like it got burnt. After cleaning the ink off the screen, it looks like the area got blocked off (looks like dried water spots). I've tried cleaning the screen, reclaiming it, degreasing it, and re-applied emulsion yet the outcome is the same. I had even used other screens (new ones as well) and the results are the same.

Could it be that the ink is going bad??

Emulsion used - Ulano RLX
White Ink - International Coating Multi-Purpose White Ink (had it since 2012)

 

[red514]

i haven't seen plastisol ink go bad before, worse case is it gets stiff and just needs to be mixed. Are you only printing white ink on the garment? what colour is the ground/garment?
i've only seen ink change color due to dye migration.
i think the ink you are using is formulated to help prevent dye migration but i'm not positive. this is an odd issue. is it changing color on press or only after it come out of the dryer? is the ink in the screen actually changing color? can you post some pics?

 

[jdp1024]

The garment color is navy blue. After I run the White ink through the screen and lift up the screen, instead of all white, i see some black areas. I don't believe the ink is changing color because I've used it before and this is the first time I've seen it happening.

 

[CTJ73]

A picture is worth a thousand words. At the very least, it would help us to visualize what is happening.

 

[jdp1024]

Here are the photos regarding my problem. Hope the community is able to help me with this.

Sent from my SCH-I545 using T-Shirt Forums

 

[Rickster]

Are you flashing? Maybe the ink is curing in the screen?

 

[Celtic]

That looks like the shirt color to me, not the ink changing color.

 

[jdp1024]

I haven't cured the ink yet. It's fresh off the screen. Right after I ran the White ink through and lifted the screen. That's what I get.



Sent from my SCH-I545 using T-Shirt Forums

 

[20vK]

How many platens do you have? 1? Maybe it's the platen. More? Does it do it on every platen? If so - probably the screen.

Think about this logically.

1. I assume you turned the screen around by 180 degrees when you reburned it, to make sure you were printing through different mesh.

2 you check your positive to make sure it does not have a light spot on that area.

3 - look for a dirty great smudge on your exposure unit that may block the light in that area during exposure

4 try a different screen of a different design on the same are to make sure the platen is not low in that area

This should get you started.

It looks like not enough ink coming though. Have you tired a second flood and pull? What happened?

Oh make sure these are not poly shirts. Poly likes to give up its color. But this looks like a simple blockage somewhere.

 

[jdp1024]

Ok here is the photo of my screen.

20vk you are right. Ink is not coming through the screen but I don't understand why. This is the first time I'm having this problem.

Sent from my SCH-I545 using T-Shirt Forums

 

[20vK]

Haha! You probably have a very thin film of unwashed emulsion on there or cured ink.

If it worked straight away for a few prints, then you have ink stuck. If it never did, it's a thin layer if emulsion left over.

Try a q tip wet with water and rub both sides where it does not pass through. Also then try with ink cleaner. See if that makes a difference. Ink cleaner removes blocked holes by cured ink, water removes thin layers of unwashed emulsion. (I use saliver, rather than water - figure extra enzymes will break stuff down faster!)

If it turns out to be ink, spray the area with ink cleaner and run with a clean shirt or towel both shirt and ink side. Then do a test print to remove any residual ink cleaner, then 1 more test print to ensure a clean sharp print. I do test prints into paper towel