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screen printing => Equipment => Topic started by: Alchemink on December 21, 2018, 12:12:03 PM
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Instead of fluorescent bulbs with the yellow sleeves for the screen room, can you replace the flo bulbs with led bulbs and still use the same yellow sleeve without messing with the emulsion?
Looking to cut power costs and we're sick of changing these things out.
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Yes, what we did was use one bulb with a yellow sleeve and one bulb with a UV film rolled up inside the a clear sleeve. LED bulbs for the most part give off very little UV, so they shouldn't be a problem.
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yep! we did as well!
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you'll probably need sleeves with LED. put them in without the sleeves and do the quarter test (Leave the quarter on the coated screen and wash out couple of days later. If the area around the quarter is not washing out, it means it's exposed and your lights will need the sleeves).
I measured the light output of our cheap LED's and they are just reaching 420nm. This is good enough for our coating and exposure section of the dark room, but not good enough for storage. The emulsion starts hardening after about 6 hours. It would probably take few days to fully cure, but that's not an option in the storage environment.
Good bulbs might not need sleeves, but it's easy to test and find out.
pierre
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I would not worry about it if you have the orange or yellow sleeves on them, that's their job really, to filter out the UV.
Steve
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you'll probably need sleeves with LED. put them in without the sleeves and do the quarter test (Leave the quarter on the coated screen and wash out couple of days later. If the area around the quarter is not washing out, it means it's exposed and your lights will need the sleeves).
I measured the light output of our cheap LED's and they are just reaching 420nm. This is good enough for our coating and exposure section of the dark room, but not good enough for storage. The emulsion starts hardening after about 6 hours. It would probably take few days to fully cure, but that's not an option in the storage environment.
Good bulbs might not need sleeves, but it's easy to test and find out.
pierre
I did that test, but with a fifty cent piece that took 12 hours to make a difference! :P
On a related note however, I switched to a small LED light on my aquarium, and developed a huge algae problem. Obviously lots more UV light than my fluorescent tube was putting out.
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as a side note, those sleeves do not block the UV 100%!!! If you read the spec sheet, it says 90%.
pierre
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as a side note, those sleeves do not block the UV 100%!!! If you read the spec sheet, it says 90%.
pierre
yes, but I would think that most of us would not be leaving unexposed screens lying around for hours anyway. Ours are kept in homemade cabinets with no light, and a dehumidifier in the summer months. In our old place, we had daylight streaming (not direct sunlight) through the windows right next to the washout sink, not a problem as long as we kept moving. Emulsion sensitivity comes into play obviously, but our thought have always been to keep them in the light no longer than necessary, which is only a couple of minutes before going to exposure.
Steve
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as a side note, those sleeves do not block the UV 100%!!! If you read the spec sheet, it says 90%.
pierre
yes, but I would think that most of us would not be leaving unexposed screens lying around for hours anyway. Ours are kept in homemade cabinets with no light, and a dehumidifier in the summer months. In our old place, we had daylight streaming (not direct sunlight) through the windows right next to the washout sink, not a problem as long as we kept moving. Emulsion sensitivity comes into play obviously, but our thought have always been to keep them in the light no longer than necessary, which is only a couple of minutes before going to exposure.
Steve
agreed! In cases like that, you will not need the sleeves. It's only if you are keeping the lights on in the storage area. . .
pierre
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^^^^^ what they said
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I've been relamping our entire facility. Yes, I use safe lights in the screen room. What I found was the yellow sleeves would fit over the end pieces on the new LEDs. Maybe it's the type of sleeve I have or the lamp itself. I'll have to try again and see what I can figure out. We have a screen room holding 600+ screens, so some are coated and stored for days at a time. I
need want safe lights
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we used sheets of this - F007-011NA
http://www.uvprocess.com/product.asp?code=FILTER+++L (http://www.uvprocess.com/product.asp?code=FILTER+++L)
i cut it to fit and taped it to the plastic diffuser on our drop ceiling light fixtures...
no need to mess with sleeves.
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I've used that also, but in my screen room I have hanging fixture with no covers. But, I can buy sheets of this, use cheap clear sleeves, and slip the film in them. Thanks for the link though.
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we used sheets of this - F007-011NA
[url]http://www.uvprocess.com/product.asp?code=FILTER+++L[/url] ([url]http://www.uvprocess.com/product.asp?code=FILTER+++L[/url])
i cut it to fit and taped it to the plastic diffuser on our drop ceiling light fixtures...
no need to mess with sleeves.
If you look at the specs, that film only blocks 90% of the UV. It is not safe to leave those lights on all the time.
pierre
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we used sheets of this - F007-011NA
[url]http://www.uvprocess.com/product.asp?code=FILTER+++L[/url] ([url]http://www.uvprocess.com/product.asp?code=FILTER+++L[/url])
i cut it to fit and taped it to the plastic diffuser on our drop ceiling light fixtures...
no need to mess with sleeves.
If you look at the specs, that film only blocks 90% of the UV. It is not safe to leave those lights on all the time.
pierre
ive never had a problem...
which specs were you looking at?
i saw that it blocked: Amber UV Filter - 99% 200nm through 470nm and 80% 470nm to 500nm
i thought our emulsions were light sensitive somewhere between 380 and 420nm - and thats what i saw when i bought the films a few years ago...
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we used sheets of this - F007-011NA
[url]http://www.uvprocess.com/product.asp?code=FILTER+++L[/url] ([url]http://www.uvprocess.com/product.asp?code=FILTER+++L[/url])
i cut it to fit and taped it to the plastic diffuser on our drop ceiling light fixtures...
no need to mess with sleeves.
If you look at the specs, that film only blocks 90% of the UV. It is not safe to leave those lights on all the time.
pierre
ive never had a problem...
which specs were you looking at?
i saw that it blocked: Amber UV Filter - 99% 200nm through 470nm and 80% 470nm to 500nm
i thought our emulsions were light sensitive somewhere between 380 and 420nm - and thats what i saw when i bought the films a few years ago...
first pdf download on the left.
http://www.uvprocess.com/products/MAINTENANCE%20AND%20SHOP.C3.UV%20FILTER%20MATERIALS.FILTER/CON-TROL-CURE%20UV%20BLOCKING%20AMBER%20FILMS%20OR%20FOILS.FILTER%20%20%20L//Datasheets/amber%20graph.pdf (http://www.uvprocess.com/products/MAINTENANCE%20AND%20SHOP.C3.UV%20FILTER%20MATERIALS.FILTER/CON-TROL-CURE%20UV%20BLOCKING%20AMBER%20FILMS%20OR%20FOILS.FILTER%20%20%20L//Datasheets/amber%20graph.pdf)
this one shows the graph for their amber sleeves (unless I am missing something).
They are also selling a cheap UV meter that is advertised as having a range up to 400nm. Since i have the same thing I know that at 400nm it has no sensitivity since that is the end of it's curve. It cuts of anything emitted in that range by 99% or more. They might be catering to the industries which are working in the mid 300nm range unlike our emulsions which are still sensitive at 420 (not much, but they are). Additionally, some of the LED exposure units on the market are actually using 405nm bulbs right in the frequency where the sleeves provide least protection.
where did you find the info that they block 99%? I looked around and can't find it. . .
pierre
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we used sheets of this - F007-011NA
[url]http://www.uvprocess.com/product.asp?code=FILTER+++L[/url] ([url]http://www.uvprocess.com/product.asp?code=FILTER+++L[/url])
i cut it to fit and taped it to the plastic diffuser on our drop ceiling light fixtures...
no need to mess with sleeves.
If you look at the specs, that film only blocks 90% of the UV. It is not safe to leave those lights on all the time.
pierre
ive never had a problem...
which specs were you looking at?
i saw that it blocked: Amber UV Filter - 99% 200nm through 470nm and 80% 470nm to 500nm
i thought our emulsions were light sensitive somewhere between 380 and 420nm - and thats what i saw when i bought the films a few years ago...
first pdf download on the left.
[url]http://www.uvprocess.com/products/MAINTENANCE%20AND%20SHOP.C3.UV%20FILTER%20MATERIALS.FILTER/CON-TROL-CURE%20UV%20BLOCKING%20AMBER%20FILMS%20OR%20FOILS.FILTER%20%20%20L//Datasheets/amber%20graph.pdf[/url] ([url]http://www.uvprocess.com/products/MAINTENANCE%20AND%20SHOP.C3.UV%20FILTER%20MATERIALS.FILTER/CON-TROL-CURE%20UV%20BLOCKING%20AMBER%20FILMS%20OR%20FOILS.FILTER%20%20%20L//Datasheets/amber%20graph.pdf[/url])
this one shows the graph for their amber sleeves (unless I am missing something).
They are also selling a cheap UV meter that is advertised as having a range up to 400nm. Since i have the same thing I know that at 400nm it has no sensitivity since that is the end of it's curve. It cuts of anything emitted in that range by 99% or more. They might be catering to the industries which are working in the mid 300nm range unlike our emulsions which are still sensitive at 420 (not much, but they are). Additionally, some of the LED exposure units on the market are actually using 405nm bulbs right in the frequency where the sleeves provide least protection.
where did you find the info that they block 99%? I looked around and can't find it. . .
pierre
its the third download on the left
http://www.uvprocess.com/products/MAINTENANCE%20AND%20SHOP.C3.UV%20FILTER%20MATERIALS.FILTER/AMBER%20UV%20PRODUCTS.FILTER%20%20%20M//SupportDocs/UV%20BLB%20Scan%20for%20Amber.pdf (http://www.uvprocess.com/products/MAINTENANCE%20AND%20SHOP.C3.UV%20FILTER%20MATERIALS.FILTER/AMBER%20UV%20PRODUCTS.FILTER%20%20%20M//SupportDocs/UV%20BLB%20Scan%20for%20Amber.pdf)
its describing the products ability to block black light "Above UVA/Visible Black Light Bulb"
i figured that since some expose with blacklight blubs, that if this product blocked those nm range, it would work for us.
i havent had any problems yet, but now you have got me doubting myself.
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Do the quarter test. Or nickels if you're on a tight budget.
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I have used yellow sleeves for years including LED'S. Never had a problem, Never thought about it being a problem and never will be a problem. Pop them on and get onto making money screen printing
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I have used yellow sleeves for years including LED'S. Never had a problem, Never thought about it being a problem and never will be a problem. Pop them on and get onto making money screen printing
Rick, just because it was not a problem for you, it does not mean such is the case for the others. If the screens in a storage room are exposed to UV, they will be partially exposed and they will vary in how much time they need for full exposure, will have problems holding repeatable dots and in general be pretty unpredictable. We are talking minor variances, but enough to cause real problems.
No question about it, do a coin test as suggested by Dave.
Pierre
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Is there is film on the market that will block 100% of the UV?