80,000 white shirts flash or no flash.

[jvanick]

Man, I wish we could print black first.  Our pre-press and reg is tight enough to do it on so many jobs but the issue we have is our quartz flash will burn the garment to a crisp in the black ink area before the ub gets flashed. 

THIS!!!! is why we rarely ever print black first..... I'd love to know how alan and these guys are printing tri blends/garments prone to scortching with black first. I have watched certain garments go up in smoke with black being flashed prior to the white being gelled. 

I suppose it goes back to what works for some doesn't work for all 

we have no issues with flashing triblends, but we use a Red Chili D with the temperature sensor... as soon as the substrate hits the set point (200 typically in our case), the flash automatically turns off...

we haven't had scorching on press since we got the Red Chili D... before that we had a Quartz Express flash unit that you'd have to turn the flash down as you continued using it as it would heat up... 

also some bulbs have a different wavelength that apparently helps too.

[jsheridan]

same here.. the quarts flashes have power adjustments.

set it to 70% .5 sec for a 'keep the glue' warm and 80% for a flash the black.

I hate to run black first for that reason, it can burn a shirt when not done right.. but this is 80k shirts.. i don't think most here can grasp the time that it's going to take to print this. things change in production setup when runs this size go on. It's a process job and keeping those colors working properly is going to be the real challenge here. By adding a wet black at the end.. it tosses in a new set of parameters and the chances for buildup and shifting are huge. Well,.. stop and clean the screen some may say.. that's cool when it's a short run to keep it crisp, this needs to stay crisp across two shifts, maybe 3 shift with up to 3 different sets of eyes keeping it approved along the way over days of production.

[ZooCity]

That's odd, set point doesn't appear to be the issue at all to me on our regular Chili.  It's that black naturally absorbs heat faster and then transmits that heat to the fabric, which is already sensitive to heat and all the while the white ub is not gelled yet.  Having a set point wouldn't resolve that in my opinion but you can sometimes resolve it by reducing the intensity, i.e. pulsing the output of the bulbs. 

I do believe it's a wavelength thing.  IR flashes don't really do this.

Did you mention variable IR wavelength bulbs?  This might be what's fixing it and has been a thought in the back of my head, to try and find a better wavelength for blends, etc.

[Dottonedan]

When burning up black ink, was that a halftone black and any black...or was it solid type?  I'm wondering if using process black down first (that is all halftones) would be good to flash early on (with Quartz)?

80% power for .5 sec?  What (if), on a similar job, I run process solid black down first, and then a poly white over top trapping the black in? The poly would then need way too much flash and burn up black I guess.

[jsheridan]

i recall poly white flashes off in the 130- 140 range compared to the 160 of normal white so it will flash first or at the same time as the black would

[Sbrem]

Man, I wish we could print black first.  Our pre-press and reg is tight enough to do it on so many jobs but the issue we have is our quartz flash will burn the garment to a crisp in the black ink area before the ub gets flashed. 

THIS!!!! is why we rarely ever print black first..... I'd love to know how alan and these guys are printing tri blends/garments prone to scortching with black first. I have watched certain garments go up in smoke with black being flashed prior to the white being gelled. 

I suppose it goes back to what works for some doesn't work for all 

What? The black is burning under the flash? Huh? I've never seen anything even close to that? In fact, if mentioned to me, I'd say, "No, that doesn't happen"... So, why is that happening? Not a challenge, it just sounds so bizarre to me?

Steve

[alan802]

I've never experienced the black burning either.  Not sure I understand what's going on.  Are we talking about the black gelling in the screen or something happening with the black ink on the shirt?  Our flash units on the RPM aren't as strong as the HiFlash units on the Centurian and we don't do a ton of triblends, but I think we've scorched 2, maybe 3 shirts in the 10 years I've been printing so something we're doing is working if that is an uncommon thing to scorch that many.  One thing we've always done with our flash units is adjust the settings which on the RPM there are many.  % from 5-100% power in the pallet up position, % power in standby (pallets down), standby time from 1 to 20 seconds and the power % while in standby mode and when you do those things right we've managed to not scorch much of anything.  We keep standby power % down to around 10% and we've been keeping the flashes at 90-95% when in pallet up position.

Oh, and one more thing, white ink flash time is one of the most important factors I look at when choosing a white ink.  It has to flash fast or I won't touch it.  So we're running larger jobs with a 1-2 second flash time so that could be a reason why we're not scorching anything.  But also, I'll admit we see triblends only a few times per month max.

[ZooCity]

I'm talking about regular spot black, wilflex Matte Black in our shop. 

It doesn't happen under IR or at least I've never seen it happen.  Hence my thought that wavelength might have something to do with it.  I don't know what else would explain some experiencing it and others not.

[3Deep]

Black burning hmmm, I know black heats up faster than most colors but burning? I've burn my share of shirts for sure but never a black ink print.

[ol man]

with us, it was an attempt to print black /underbase/flash, then top colors..for me i had traditional set up like this to control black dot gain...

[bimmridder]

I learned that on a nice poly sweatshirt I was printing. My fault, I wasn't paying attention. Black, flash (burn), well, didn't get to the poly white, but would have been next. I've never claimed to be smart.

[Sbrem]

I learned that on a nice poly sweatshirt I was printing. My fault, I wasn't paying attention. Black, flash (burn), well, didn't get to the poly white, but would have been next. I've never claimed to be smart.

Yep, that's how we print a black and white on poly, still have never burned the black. There's always something. Now I suppose it will start to happen to us, LOL...

Steve

[DannyGruninger]

I can assure you guys it has nothing to do with how we flash or the type of flashes. IMO the roq evo flashes we use are by far the smartest flashes on the market. We actually have never had this happen on our Roq but we did have it happen multiple times with our m&r "D" flashes. What I am referring to is if you have a design with a small patch of black ink and large solid patch of white ink and you print the black before the white, obviously the white will take much longer to flash then the black. What I've seen happen is the black absorbs all the energy from the flash and the sensors on the flash keep flashing due to the white ink not being flashed. If your printing on a garment that has a low scorching characteristic then the black will actually burn the garment. A lot of the times it looks fine until you stretch the print only to see the black has become brittle due to heat. But from the testing I have done it has more to due with the garment then anything.

[JBLUE]

Lets dispel the first rumor. Its ok to flash white shirts.....lol Do it right and print the black last. We print like Danny. I can count on one hand the print jobs where we have stepped on black in 8 years. Of those they are on poly. Run two blacks to control gain and run the sh!t out of it. their other screens are going to cause more issues that running the black last will.

[Underbase37]

I can assure you guys it has nothing to do with how we flash or the type of flashes. IMO the roq evo flashes we use are by far the smartest flashes on the market. We actually have never had this happen on our Roq but we did have it happen multiple times with our m&r "D" flashes. What I am referring to is if you have a design with a small patch of black ink and large solid patch of white ink and you print the black before the white, obviously the white will take much longer to flash then the black. What I've seen happen is the black absorbs all the energy from the flash and the sensors on the flash keep flashing due to the white ink not being flashed. If your printing on a garment that has a low scorching characteristic then the black will actually burn the garment. A lot of the times it looks fine until you stretch the print only to see the black has become brittle due to heat. But from the testing I have done it has more to due with the garment then anything.

This^

If you aren't using quartz flashes you'll probably never experience this. Older quarts flashes are more likely as well, and the wavelength of the bulbs plays a big part. Some blended shirts are crazy sensitive to this.

Murphy