UV on reflective vs solvent

[Norman Clifton]

Does anyone know if UV print is the same effect as solvent printing on reflective -
UV layers ink on top[ of the media so not sure it works the same as solvent (no experience with Solvent just UV and AQ)

 

[Vortex37]

Solvent penetrates the surface of the media more and thus doesn’t have texture like UV ink, so that’s what you want if you are doing vehicle decals because it won’t crack.

 

[Boudica]

UV ink is more opaque than solvent, so I would think it would eliminate any reflective qualities in the print. We have both capabilities, works great on the eco solvent printers, but we've never tried it on the UV flatbed. I don't think it would look as good though.

 

[Vortex37]

UV ink is more opaque than solvent, so I would think it would eliminate any reflective qualities in the print. We have both capabilities, works great on the eco solvent printers, but we've never tried it on the UV flatbed. I don't think it would look as good though.

I print UV on reflective blanks on our HP flatbed and the reflectivity still shows quite well through the ink, surprisingly so. When I really want it opaque (as I do for one customer who does solely black text on HIP reflective) I put it in backlit mode and it lays the ink on so thick it looks like vinyl lettering.

 

[mkmie]

Really?. From what I was told we cannot print reflective on the UV printer because the reflection interferes with the UV lamps that cure the ink.
Seemed reasonable but perhaps I am wrong.

 

[Boudica]

Really?. From what I was told we cannot print reflective on the UV printer because the reflection interferes with the UV lamps that cure the ink.
Seemed reasonable but perhaps I am wrong.

we were also warned very strongly to NEVER print on a mirror... but I know someone who says they do it all the time. Go figure. Not gonna try it though.

 

[signheremd]

We UV print on reflective coated aluminum panels all the time. Most colors still reflect. Personally I prefer the look of Solvent printed reflective vinyl, but both work.

As far as not printing on mirrors, the main thing is don't look at the light reflected out while printing - that can blind you. The only other issue is that it can cure ink coming out of the head, so be sure to clean it frequently after so printing.

 

[netsol]

g

we were also warned very strongly to NEVER print on a mirror... but I know someone who says they do it all the time. Go figure. Not gonna try it though.

it won't hurt the equipment, BUT YOU CAN GO BLIND, LATER THAT NIGHT

back in the early 80's a good client had a 400 gal. liquid sugar tank with a uv light to retard mold growth
he didn't understand that uv is invisible AND VERY DANGEROUS, like staring at an eclipse
he set the light on a bench, powered on, thinking the bulb was bad

later that night, he woke up and discovered he was blind. at the hospital, the doctor said his vision MIGHT RETURN. after 2 very long days his vision returned to normal.

SO, NO MIRRORS, your eyes don't see the light, so pupils stay wide open

 

[Boudica]

g

it won't hurt the equipment, BUT YOU CAN GO BLIND, LATER THAT NIGHT

back in the early 80's a good client had a 400 gal. liquid sugar tank with a uv light to retard mold growth
he didn't understand that uv is invisible AND VERY DANGEROUS, like staring at an eclipse
he set the light on a bench, powered on, thinking the bulb was bad

later that night, he woke up and discovered he was blind. at the hospital, the doctor said his vision MIGHT RETURN. after 2 very long days his vision returned to normal.

SO, NO MIRRORS, your eyes don't see the light, so pupils stay wide open

What we were told is that the reflection of the UV light back up on to the heads would cure the ink in the heads. Like I said, I know someone who does it - but this is one of those rare cases where I DONT need to find out for myself.

 

[Vortex37]

Really?. From what I was told we cannot print reflective on the UV printer because the reflection interferes with the UV lamps that cure the ink.
Seemed reasonable but perhaps I am wrong.

We were told reflective is fine as long as you manually clean the heads after a run, so that’s what we do. That’s from the Grimco tech who installed our flatbed.

He did say mirrors are a no-no, but he went on to elaborate that actually you can print a mirror if it’s a certain type. Apparently there are first surface and second surface mirrors and one of them is ok to print on because it reflects the light at a more oblique angle. I don’t remember which is which - we don’t print on glass for a myriad of other reasons and that includes mirrors.

 

[ikarasu]

It all depends on how much you're printing.

If you're going to print 50 signs on reflective.... I wouldn't do it on UV. We used to screen print 1000s of realtor signs, then just imprint the names - on our fb500 whenever we did it to reflective, the nozzles would start dropping.... They always came back with a cleaning, but we were printing 6" areas, I can't imagine printing tons of full signs and it not clogging the head.

What printer is it?

If you're truely worried and have a flatbed.... Most flatbeds can print with the UV lights off, then you can cap / cover the Printhead and then run a pass with just UV lights. Obviously you're taking twice as long to print this way... But at least you're not risking ruining a head. Good if you have long lengths of UV printing to do.


Of course it all depends too. On our q500 the UV lights are a good 10-12" away from the heads, and it prints a few cm above the media... There's no way for the light to get to the heads even on a mirrored surface. So it's pretty much case by case.


As for the actual print - our fb500 was opaque and it took away from the reflective was. Our q500 ink gives it a metallic look... It's unique, but you do lose some reflectivity.

 

[Norman Clifton]

I never considered reflective curing back wards to the heads. We have printed the UV on the reflective and it looked good -however i was wondering if the solvent allowed more of the reflective qualities to show through the ink. Thanks for the feedback everyone.

 

[SignMeUpGraphics]

What we were told is that the reflection of the UV light back up on to the heads would cure the ink in the heads. Like I said, I know someone who does it - but this is one of those rare cases where I DONT need to find out for myself.

I had a chat with our tech recently and mentioned your concerns. He said that they are very warranted due to differing head/lamp design to our machine, and that your tech is correct in saying that you shouldn't be doing mirrors on your machine. Just thought I'd pipe up and let you know.
We've been doing mirrors for close to 10 years now on the same machine... no issues with ink curing on the heads, nor is anyone blind yet. A bit of mindfulness to the dangers of UV has kept the workshop safe so far.

 

[Boudica]

SignMeUpGraphics I was hoping you would jump in here Thanks for the update!

...I was thinking it had something to do with which hemisphere you are in.

 

[SignMeUpGraphics]

Hahah, yeah the light bounces in the opposite direction down here