DANGERS of UV Printing

[M D Gourley]

Hello Everyone,
Had a chance to work at a large Signage Firm out of town for a day as they needed an extra pair of hands. I was just set up out the back with a load of vinyl application work which was situated approx 10 metres away on a workbench facing their large flatbed UV Printer that was in a glass office type area so the printer could be easily seen when printing. I was working away and looked up I could see the entire UV light bulb moving left to right while printing...wow that's bright, I thought and turned to ask another worker that was behind me..."Should I be seeing that UV light and should it be behind a shield so it can not be seen?"....no-one was around to ask....a large firm with 20 or so workers in the workshop and 'No one to be seen', that's odd I thought.
Anyway, I carried on with what I was doing, then the UV Printer operator came in as the printer had stopped printing. he asked me over to look at the media that was printed on and asked me way do you think the print image quality looks like this....I looked at it and it looked as if the ink had blistered but I said I was not sure as I do not know or have operated a UV Printer before.
About 4 hours later I could feel my face burning and said to the Foremen I have to leave as something has come up...got back home, looked in the mirror and my face has got a sunburn type feel and look to it.
Did some research and you can indeed get some UV Radiation burns from a UV Printer if the operator has the back shield off and the curing UV set very high....Negligent or not!!

 

[FrankW]

You should not expose yourself to that light, this is a lot of unhealthy UV-emissions. The machines I know protects the users from that light, because you are in danger of skin cancer if exposing yourself regularly, and it is bad for the eyes if looking directly into it. But I saw it sometimes that for example at the HP Scitex FB-Series the customer shortcuts the security switch to operate that machine with open covers, but this is not recommended. At the small Scitex FB, there are windows to look into the printer, but with UV-filters.

 

[ikarasu]

I always have the back of our printer open. I like being able to see stuff as it prints... Usually the lights are so close to the media it doesn't matter.

I was doing a test and printing on golf balls with a jig... I went to look at it to see if I was printing on the right spot... since it was printing on golf balls, it was like 3" in the air and the light was blinding.

I still keep it open for coroplast... I never even thought about the UV radiation. I'm never in the back when it's printing, but I may start printing with it down now!

 

[White Haus]

Getting burned from a flatbed 30 feet away in another room? Seems a little dramatic to me.

Our flatbed doesn't have covers and you can see the UV light from anywhere in the shop - has never caused any issues.

 

[JoeDG]

What printer was it? LED UV lamps should not be type that cause sunburn...I forget which type (A or B etc), and as White Haus says - from 10 metres!?
But yes...don't look into it!

 

[jeffdpia]

UV googles are a good safety measure as well as staying clear of the UV ink mist that surrounds the print head. One should also wear gloves when handling UV printed products as people have been known to become sensitized to the ink.

 

[AMGearhart]

I run a HP Scitex and remain very conscious of the light when checking quality during printing. When I run mine, the printhead are so close to the material with the bulbs no much higher, plus the shutters opening and closing as it prints, I've never felt an issue regarding exposure. But I keep the output & input hoods down while printing. I do know the bulbs can get hot enough to blister paint, if one isn't careful. Wasn't sure about other issues. But I'll keep a leery eye on it and do a lot more research going forward.

 

[Bobby H]

It is never good to look directly at UV lamps. They can damage eyesight. The really bright curing lamps in these UV printers can potentially burn and scar the retina. Removing the covers that block out a lot of light is a bad idea. The print head and its covers run very close to the material. I get the impression some are removing the covers to allow a little more wiggle room for printing on material that isn't perfectly flat. The guy who installed our Mimaki printer told us to just not even try printing on flawed materials, that it's not worth the risk of a potentially costly head crash. Use the function to check material thickness religiously.

One should also wear gloves when handling UV printed products as people have been known to become sensitized to the ink.

People should be handling the blank material with gloves and/or clean the material thoroughly before printing. Finger prints will show up in the finished prints big time otherwise.

 

[uvgerard]

Hello Everyone,
Had a chance to work at a large Signage Firm out of town for a day as they needed an extra pair of hands. I was just set up out the back with a load of vinyl application work which was situated approx 10 metres away on a workbench facing their large flatbed UV Printer that was in a glass office type area so the printer could be easily seen when printing. I was working away and looked up I could see the entire UV light bulb moving left to right while printing...wow that's bright, I thought and turned to ask another worker that was behind me..."Should I be seeing that UV light and should it be behind a shield so it can not be seen?"....no-one was around to ask....a large firm with 20 or so workers in the workshop and 'No one to be seen', that's odd I thought.
Anyway, I carried on with what I was doing, then the UV Printer operator came in as the printer had stopped printing. he asked me over to look at the media that was printed on and asked me way do you think the print image quality looks like this....I looked at it and it looked as if the ink had blistered but I said I was not sure as I do not know or have operated a UV Printer before.
About 4 hours later I could feel my face burning and said to the Foremen I have to leave as something has come up...got back home, looked in the mirror and my face has got a sunburn type feel and look to it.
Did some research and you can indeed get some UV Radiation burns from a UV Printer if the operator has the back shield off and the curing UV set very high....Negligent or not!!

TCS Technologies is a manufacturer of UV curing lamps hence we have many years’ experience working around UV light. First: UV light does not bounce well. For you to get the type of burn you describe, you need a direct line of sight to the UV. Unless you had safety glasses on, I would have expected you to have a “flash” burn similar to looking at a welding arc. Symptoms include eye pain coupled with a feeling that something (sand like) is in your eyes. A cheap precaution is wear UV safety glasses. We sell them for $15.00 or purchase from a safety equipment store.

UV intensity is dependent on distance from the source. Intensity is an inverse square law. The amount of energy received at 10 meters distance is 100 times less that that received at 1 meter. Not only must your printer have had all its optical shielding removed, the lamp must have a direct light path to your location.

I would alert the machine manufacturer. They should have had some sort of interlock to prevent such an occurrence. Does not matter if conventional arc or LED, the machine needs optical shielding.

 

[M D Gourley]

Getting burned from a flatbed 30 feet away in another room? Seems a little dramatic to me.

Yes, the way you are describing it, that does sound dramatic...but it was direct line of site as I could see the entire printer and the lamp working on the job, and the sunburn effect on my face was not imaginary...lol .There are other exposure hazards that should considered as well...Inhalation of mist Ink and ozone, contact with uv curable inks...as per this site below.
https://teamster.org/content/ultraviolet-process-hazards

 

[M D Gourley]

What printer was it? LED UV lamps should not be type that cause sunburn...I forget which type (A or B etc), and as White Haus says - from 10 metres!?
But yes...don't look into it!

Sorry, I am not sure what type of printer it was, as this is not in my area of knowledge...UVB rays, which affect skin's top layer, cause skin cancer and most sunburns. Although UVA and UVB rays pose the greatest risk for sun damage, people who work with welding torches or mercury lamps may be exposed to UVC rays, the most dangerous type of UV radiation.
...from the site https://www.doctoruv.com/difference-between-uva-uvb-uvc-uvv
UV curing is a photochemical process where different types of UV wavelengths are used to cure inks, coatings, sealants and adhesives. The low temperature, photochemical reaction eliminates the need for solvents and drying time, making it a faster process than two-part adhesives. The UV ranges used for UV curing are A, B, C, and V.

Each UV has a different wavelength range that determines how deeply it can penetrate the substrate. The appropriate UV is chosen for an application based on the substrate being used and the desired curing effect:

• UVC is a shortwave ultraviolet used for top surface curing that creates surface hardness and abrasion resistance
• UVB is a midwave ultraviolet capable of deep penetration curing that creates coating and adhesive toughness
• UVA is a longwave ultraviolet used to cure the deepest layers and provides adhesion and cross linking
• UVV is a visible ultraviolet that is used for silver pigment and Titanium Dioxide curing, as well as adhesion

 

[Bly]

We work around a UV printer every day and have never experienced anything like this.

 

[Gino]

I don't think anyone is denying you didn't get any exposure, just not to the degree you are feeling. If this was the case, whatever you have compared to our OSHA, would close that place down with one complaint if what you are saying is anywhere near true. Our flatbed has been running for over 10 years and no one has ever experienced what you have. I would think if you looked directly at those lamps, you should have your eyeballs checked for damage......... seriously. Copying and pasting things from any site you can find on the subject, doesn't always mean you are inserting it at the right time or for the correct situation. You said yourself, you know nothing about this stuff, but it looks as if you've done a lotta homework on it. I would say you should call this shop and tell them they will be responsible for all of your medical bills related to what's happened to you. Then, you'll see how this stuff really can or cannot effect you.

 

[SignMeUpGraphics]

I'm with Bly and Gino... 5+ years of UV printing, never seen this happen to anyone.
Inverse square law says that if you were getting burnt from 10m away, the panels they were printing on should have being subjected to enough UV to melt them.

 

[Texas_Signmaker]

My wife used to pay for that kind of UV exposure... she got some sense not to do it anymore though.

 

[flyplainsdrifta]

you'd have to have direct exposure for many repeated hours to get that *sunburn* effect. to me, it sounds like youre describing actual radiation sickness, which would take quite a large dose to get what youre talking about. way more than a printer can output.

 

[JR's]

Just don't go into the light. lol

. I got hit in the head with a golf ball and I swear that's what my son was telling me.

 

[Bobby H]

My wife used to pay for that kind of UV exposure... she got some sense not to do it anymore though.

At least the tanning salons give customers protective goggles to wear in the tanning beds. Or at least they're supposed to do that. I never did get into using tanning beds or just even laying out in the sun as an adult. Got sunburned plenty as a kid (especially when we were stationed in Yuma, AZ). I just pray I don't develop skin cancer here decades later. One of my high school classmates successfully battled skin cancer, but the treatment ordeal was pretty horrible for him. After witnessing that I've tried to take more precautions as an adult.

you'd have to have direct exposure for many repeated hours to get that *sunburn* effect. to me, it sounds like youre describing actual radiation sickness, which would take quite a large dose to get what youre talking about. way more than a printer can output.

A UV printer doesn't even emit the right type of radiation to cause something like radiation poisoning. Gamma and X rays are the really bad ones; such rays are highly energetic and penetrate the full body with no problem. Clothing makes little difference. High doses of Gamma and X radiation will cause widespread damage at the cell and DNA level. UV radiation is still bad. A severe sunburn (I've heard it called "sun poisoning") can make someone weak and nauseous. A bad enough sunburn can put someone in the hospital. We're all familiar with the long term consequences of repeated sunburns and UV exposure.

 

[player]

Some substances ingested will intensify the effects of UV exposure. Celery is one of them.

 

[netsol]

in 1978 i worked for a manufacturing company that had 400 convenience stores. we had a food plant with a 1000 gallon liquid sugar tank, with a uv light inside to keep mold growth inhibited. this light was just outside the visible spectrum.

we had a mechanic working on it, who did not turn off the lamp, when he went inside the tank. it is just like an eclipse (at the other end of the spectrum) the pupil doesn't react and shocks the optic nerve

tony woke upthe following morning and was completely blind. at the hospital they said the optic nerve often recovers. sent him home. after 72 hours he woke up with normal eyesight again. (longest 3 days of his life)

we all had a healthy respect for uv light setups after this.

energy decreases with the square of distance. (twice as far away 1/4 the light, 4 times as far away 1/16 the light.) sunburn effect should take a LONG time. i don't over react to safety issues, but this machine needs it's covers in place