New screen room under construction

[Binkspot]

Don't go out and buy led lights yet but in my research today it appears LED lights emit no UV or IR unless designed to do so. With this being said I will be buying some different styles of bulbs including fluro tube LED lights and set up the coin test when I get back in town. I will try it for two weeks and see what happens. If someone has already tried this please let me know.

[TCT]

Brian got any updates?!
LED bulbs for the most part don't hit the right spectrum? I want to put up some new lights in our old embroidery room since we are taking the walls down and making it part of the printing area, but I was waiting for you to do the hard work and any "brain" work- I strain mine enough just trying to keep up with the forum! 

[Rockers]

That's from a manufacturers website
"Some industry sources claim that LEDs produce no UV radiation. This actually isn’t true. LEDs do produce a small amount of UV, but they emit even less. That’s because the amount that is produced is converted to white light by the phosphors inside the lamp."

[Binkspot]

Slow down, so far I got a high bay (can) LED insert and a incandescent replacement each in its own makeshift dark rooms directly over 155 mesh screens coated 1/2 with Satti PHU. This stuff exposes pretty quickly so I figured it would be a good starting point. Started the expearment last Monday, would like to keep them in there until April 7th (two weeks) and see what happens. In my mind even if it does expose a small bit I will be able to tell how long the light is safe by how it washes out and go from there. If these bulbs work ill set up another test for a week using fluro tube replacements.

I don't want to rush this, if I'm wrong I could ruin a whole bunch of screens for myself and others. I would rather error on the side of caution.

[jsheridan]

I'm about done building our screen room area and have done the coin on the screen test and with UV blocking light sleeves (400 and 500 nano blocking power) on both sets of lamps in the room (8 t5 5000k bulbs) and i'm still getting light scatter.

I have too change out all the bulbs for LED's and will be ordering new bulbs today.

I'll report back once they arrive and I re-test the room.

[bimmridder]

Maybe someone from an emulsion company would  be kind enough to jump in with some suggestions. I have yellow sleeves on my lamps. White light would usre be nice. I don't know how my screen guy can stand to work in that yellow light for 10 hours a day.

[ABuffington]

Yes you can get clear fluorescent sleeves from Encapsulite that are UV safe

Model: SO C20 UV Daylight White 400

Baypress sells them and there are others as well.

http://www.baypressservices.com/acatalog/Encapsulite.html

Al

[244]

Maybe someone from an emulsion company would  be kind enough to jump in with some suggestions. I have yellow sleeves on my lamps. White light would usre be nice. I don't know how my screen guy can stand to work in that yellow light for 10 hours a day.

We use the clear sleeves here at M&R in our screen department with good results. We have a portable meter that we use to monitor the area and it shows no U.V.

[bimmridder]

Thanks, gentlemen.

[ScreenFoo]

To be honest not sure where to source them. Someone mentioned some large screen supplyers were starting to Cary them. I read an article a while back about them and someone posted pics of a screen room with them some time ago. I will most likely go that route when we do our screen room. I hate working under the yellow lights.

As long as you stay out of the 260nm-310nm spectrum you should be fine.

Greg has also suggested painting the walls and ceiling with a cream yellow color to absorb the stray UV. It was like a 1205U or something, I got it written down some where.

FWIW, from the spectral analysis I've seen from exposure equipment, most are very active between 300-430 or so--IIRC, the 300 range is UVB and rather nasty for you even in small doses. 

I know you can get 'white' LED's that will crosslink emulsion, although I'd think the 3K ones (that are supposed to look like incandescent bulbs) would be the way to go... probably would not be entirely light-safe, but more so than most of us need.

[jsheridan]

I've got the clear sleeves from UV process that block up to 400 nm and the amber sleeves that block up to 500 nm.

BOTH of them FAILED the coin test on the screen after 4 hours of exposure in the room with the lights turned on.

I'll note that the clear sleeves cooked the screen completely, the amber sleeve was much better but still failed.

The bulbs being used are 4' T5 32watt 5000k daylight bulbs x8

I have UV resistant coated plexiglass 'windows' across the entire screen room, the same coin test PASSED with 4 hours of normal daylight passing through the windows.

[jsheridan]

dbl post..

[Binkspot]

Well after two weeks both LED light sources failed the coin test to a point. It appears around eight days the emulsion starts to cross link and by days 10-11 pretty much exposed. Going to see if I can find a UV meter to use and try some more experimenting.

[mk162]

we found the same thing with LED's, while they say zero UV, they did expose a screen in about 5 hours.  So we sleeved them and we haven't had any more issues...also, we turn them off when we aren't in there too.

[jsheridan]

Well after two weeks both LED light sources failed the coin test to a point. It appears around eight days the emulsion starts to cross link and by days 10-11 pretty much exposed. Going to see if I can find a UV meter to use and try some more experimenting.

2 weeks, i'd say they passed.

I'm not worried about that many days of exposure as our screen turnover is about 2 days. I'm more worried about ambient light in the room causing problems with fine tonal detail on quick exposing polymer emulsion.