Newbie w/ screen burn issues

1454 Views 14 Replies 7 Participants Last post by adivito, Jul 16, 2010

thestitchwitch

Discussion Starter · Jul 14, 2010

I'm finally to the point of doing some actual screens for a print job.

My biggest concern was how my images were going to print. I'm using an Epson 1400 with oem inks. I'm also using films for inkjet printers. I have my settings at Photo & text, ultra premium photo paper glossy, Always overprint in Black, Print separations. The films print out nicely--

However......I can't get the screens to burn properly. I've read about the screen exposure test that you can buy, which I will be looking for today.

Here's my setup-- It's a Brown, 500W exposure box. The screen with the film sit directly on the glass. I have yet to get a proper burn. Screens are 110 count.

I'm using Saatichem Emulsion (pink stuff). The image I'm trying to burn is a 2 color. The bottom color (not a lot of detail) I FINALLY got to burn by using 1000w halogen shop lights- for what seemed like forever!! However, the black outline, I just cannot get to burn. I went through 6 screens last night trying to get the image to burn and washout.

My thoughts---overexposure. Now that I've read that everyone places their image a certain amount of inches away from the bulbs. Mine sits on glass. I've tried everything from 5 mins to 20 mins. No luck yet. I get some washout---but the lined detail won't.

HELP PLEASE!! I've got to get this screen burnt early today. All of you are such a wealth of knowledge, I know SOMEONE will give me more info than what I've already read.

Thanks a ton!

1 - 15 of 15 Posts

PositiveDave

· #2 · Jul 14, 2010

Does the emulsion just wash off?
Sounds like the glass that you are using might be uv treated?
Try an exposure without the glass.

thestitchwitch

Discussion Starter · #3 · Jul 14, 2010

No. Itt won't wash unless I reclaim it. I can see the image slightly
Burnt in, but it never washes.

I doubt the glass is UV treated as that would
Defeat the purpose, wouldn't it? It was manufactured for exposing screens.

Who knows, call me Crazy & Frustrated!!

RideOutWear

· #4 · Jul 14, 2010

Sounds like your overexposing it. Try less than 5 minutes. Also r u working around uv safe lights?

thutch15

· #5 · Jul 14, 2010

RideOutWear said:
Sounds like your overexposing it. Try less than 5 minutes. Also r u working around uv safe lights?

That was my first thought. Are you sure that you are not pre-exposing them with another light source.

Also, regular inkjet positive does not hold very much ink. You might try to print to positives and double them up to make sure that like is not getting through.

thestitchwitch

Discussion Starter · #6 · Jul 14, 2010

Yes, I have to room darkened, minus a small door at the other end. About 100 yds away, cracked for a small amount of light.

So based on using an exposure unit 500 watts, and the glass appears to be less than 6" away from the bulbs, maybe 5-7 minutes?

thutch15

· #7 · Jul 14, 2010

thestitchwitch said:
Yes, I have to room darkened, minus a small door at the other end. About 100 yds away, cracked for a small amount of light.

So based on using an exposure unit 500 watts, and the glass appears to be less than 6" away from the bulbs, maybe 5-7 minutes?

If I am reading this right you said you got the inside details to work fine, but the outline is not coming out. It could be due to you only being 6" away from the screen. You might need to pull the light source back a little and a some to you time. That way the outer edges are getting exposed.

thestitchwitch

Discussion Starter · #8 · Jul 14, 2010

I did double the films this time, too. And I'm working 5 minutes right now to see how that works. Yesterday I achieved a better burn using 1000 watt shop lights.

5 minutes in the exposure unit was too much.

RideOutWear

· #9 · Jul 14, 2010

I use a work light and do 4:30 so try lower times

thestitchwitch

Discussion Starter · #10 · Jul 14, 2010

Worklight and about 3 minutes, screen about 12 inches away.
Excellent burn, finally!!!

Stupid manufactured unit, ugh.

Thank you all, VERY much.
Troy, have a couple of questions for you. Can you email me? You still have my personal email?

thutch15

· #11 · Jul 14, 2010

thestitchwitch said:
Worklight and about 3 minutes, screen about 12 inches away.
Excellent burn, finally!!!

Stupid manufactured unit, ugh.

Thank you all, VERY much.
Troy, have a couple of questions for you. Can you email me? You still have my personal email?

email sent!

Reactions: 1

thestitchwitch

Discussion Starter · #12 · Jul 16, 2010

Just wanted to thank everyone that replied so quickly to my post. I have successfully burned several screens using the worklight setup. Go figure----it works better and more efficiently (quickly) than the manufactured exposure box!

tpitman

· #13 · Jul 16, 2010

What kind of a bulb is in the Brown? Halogen?
With Saatichem's TextilPV emulsion, using unfiltered blacklight fluorescents, and a 110 screen coated 2/2 I'd guess a burn time of around 5 minutes. On screens like 195s I used to get burn times of around 3-1/2 minutes, and the exposure was spot on.
That's another thing with the pure photopolymers. They don't have the exposure latitude that dual-cure emulsions have. You really need to dial in your exposure times to within a half minute or so.

Reactions: 1

sartora1

· #14 · Jul 16, 2010

I'm new to printing as well and had a question related to this. I'm attempting to print t-shirts, and I'm freehand drawing my designs onto a treated ascetate which works ok, but the results are not consistent. The image never comes out opaque enough, and I'd rather not have to draw 2 of every image by hand to double it up if I don't have to. Is there and other method that would make this easier because it's frustrating me to death that I can't figure this out? Thanks.

adivito

· #15 · Jul 16, 2010

sartora1 said:
I'm new to printing as well and had a question related to this. I'm attempting to print t-shirts, and I'm freehand drawing my designs onto a treated ascetate which works ok, but the results are not consistent. The image never comes out opaque enough, and I'd rather not have to draw 2 of every image by hand to double it up if I don't have to. Is there and other method that would make this easier because it's frustrating me to death that I can't figure this out? Thanks.

Im guessing you are using sharpies or something of the sort to draw. Try to find a lithography pen it will be completely opaque.

Reactions: 1

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