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screen printing => Newbie => Topic started by: Du Manchu on January 14, 2013, 09:56:17 AM
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I am new to working with a quartz flash and am finding that it takes much longer that expected to cure shirts....initially. Do these things require a good bit of run time to come up to temp. I am finding it taking 10+ seconds or a double hit at 7+ to flash cure a shirt. If I flash it 30 times just auto cycling I can get down in the 5-6 second range, but if there is a problem on press, or stacking shirts for a few minutes, I am back to square one. Which resulting in bad prints, cleaning bottom of screens, etc... What gives? Is this common?
A possible problem may likely be that my building runs 208v instead of 230v.
Any thoughts would be appreciated.
Dewey
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what size, brand and model flash are you using?
208v vs. 230v can be a problem, but can be resolved with the correct bulbs.
we have a cayenne that was shipped with 230v bulbs and didnt flash as expected. when switched to the 208v bulbs, the flash worked as expected.
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You have to figure that is about 10% less voltage than it is expecting.
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I am new to working with a quartz flash and am finding that it takes much longer that expected to cure shirts....initially. Do these things require a good bit of run time to come up to temp. I am finding it taking 10+ seconds or a double hit at 7+ to flash cure a shirt. If I flash it 30 times just auto cycling I can get down in the 5-6 second range, but if there is a problem on press, or stacking shirts for a few minutes, I am back to square one. Which resulting in bad prints, cleaning bottom of screens, etc... What gives? Is this common?
A possible problem may likely be that my building runs 208v instead of 230v.
Any thoughts would be appreciated.
Dewey
we are in the same boat. Especially on the MHM presses, flashes are not fire and forget, you do have to keep an eye on it (your platten temperature will impact the flash time so you'll have to adjust as you go). If you are running honeycomb plattens, they do not retain the heat like solid aluminum so the flash times are longer. On top of that, MHM starts counting before the press turns (as it is preheating the bulbs) so what seems like 6-7 sec's is really 4 - 5.
pierre
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another thing you can do is cycle your press and heat up your pallets prior to starting production. or maybe find a white that has a quicker flash time. also you could run a higher mesh to better control the thickness of the image your trying to flash.
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Pierre, there should be an adjustment to change when the press fires the flashes, by index or after index.
Tradeoff is electricity ($) or time, you decide.
Quartz flashes do take some getting used to, and you are right, especially in the winter you gotta keep moving.
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It takes about 6-10 indexes for our flash to get fairly warmed up, but we are never in the 5-7 second range for flashing. We usually start at 4-4.5 and go down as the press indexes a couple revolutions. On long runs with 2 flashes going, the pallets get pretty warm, not hot, then our flash times are down to at least 2 seconds, even for thick 110 ink deposits.
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It takes about 6-10 indexes for our flash to get fairly warmed up, but we are never in the 5-7 second range for flashing. We usually start at 4-4.5 and go down as the press indexes a couple revolutions. On long runs with 2 flashes going, the pallets get pretty warm, not hot, then our flash times are down to at least 2 seconds, even for thick 110 ink deposits.
How many watts or amps/volts?
I love/hate honeycomb pallets.
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They are labeled 208-240V and 26 amp.
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They are labeled 208-240V and 26 amp.
I'm assuming 3 phase then?
26 amps is super small for single phase.
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Oh yeah, 3 phase.
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With our flash we always preheat the palettes, several full rotations at about 5 seconds really works well. Once printing we start slowly lowering the flash time as everything gets heated up and by time we get to the sweet spot of time its no more than two seconds. Fortunately on our machine we have a preheat for the flash, adjustable for idle time and for how long to actually preheat. I have it set to preheat for 6 seconds, unless we walked away for like a half an hour that is more than sufficient to preheat the bulbs and get rocking again.
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With our flash we always preheat the palettes, several full rotations at about 5 seconds really works well. Once printing we start slowly lowering the flash time as everything gets heated up and by time we get to the sweet spot of time its no more than two seconds. Fortunately on our machine we have a preheat for the flash, adjustable for idle time and for how long to actually preheat. I have it set to preheat for 6 seconds, unless we walked away for like a half an hour that is more than sufficient to preheat the bulbs and get rocking again.
Ditto, exactly. You need warm platens and the flash cure warmed up, then rock and roll lowering flash times as you go. If you need to stop for a while, raise the flash times when you start again.
Man I'm looking forward to more WB/DC this year.
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Honeycomb pallets will cool down really quickly. If you get to your fastest/optimum flash time, and then have to stop for even just a minute,
you'll have to bump your time back up.
Like I said, love/hate.
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We preheat the pallets. Do about 2 sec flash time.
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Does anyone here actually check the temp of the pallets or do you just go by feel. I'm pretty sure I'm fighting the flash issue and getting it dialed in. The more I read, the more I learn what i'm possibly doing wrong. I have honeycomb pallets and they heat up fast and cool down quick. I also have "smart" flashes that have a probe to read temp, but i'm thinking i need to get everything going first and then swith over to the probe setting.
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Always preheat the platens at start up, if its first print of the day a couple revolutions works, if its a later job and the palettes are still some what warm then a single revolution is usually fine. Thats where we start off from, then start lowering the flash time till about 2 seconds. I am sure those honey combs make it much more difficult I feel for you.
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I've been spinning them until get to about 130 degrees. have no idea if thats too hot, not hot enough, just right. What sucks with these is I print by my self so even when I think I get them right, for me to walk around the press and start turning things down, everything starts to cool down (ugh) and then i'm almost back to square one. Need to hire someone to walk around and change temps/time on flashes.
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Like everyone has said preheat before printing. Don't stop unless you absolutely have to.
If your press will do it set it in heating mode before you walk over to make adjustments and dry cycle the press while walking over to make adjustments with it flashing. The other option would be to make a remote temp/ time control that could be attached to the main control panel to make adjustments on the fly. I would just pull the control out of the flash, add some wire and mount that controler to the main panel. Just my 2 cents.
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I always just turned the press on print mode with just the flashes on and ran it for a minute or two while I got things ready to go. Then when I was ready to lower flash times, I just pressed the "print finish" button and walked to the flashes and turned them down while the press is still running and flashes are still going on and off so there is no cool down happening. Then when I get back to the load station I simply press the "print finish" button off and continue loading shirts and then the print heads start printing again when a shirt is there and the flash units never turn off or have a chance to cool down. I measure our pallet temps from time to time and I try to stay below 150 when we are running so we don't get any issues with ink drying/gelling in the screen and warped pallets. I'd say if your pallets are at 130, you're good to go but keep and eye on them. I've been in shops where the pallets were too hot to touch with your hand and ink is gelling in the screen and bad things are happening all over the place. If you let the press sit for 30 seconds and don't have the flashes cycling then yeah, we have to print slow for the next few indexes til they warm back up but it's just 2-3 indexes.
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Thanks for the multitude of feedback. I'm glad to know its a common struggle. FYI, the flash made by 2M. 230v, 26 amps. Building running 208v 3 phase. I may be checking into the 208v bulbs. That my help, if the expense isn't too much of a shocker.
Thanks to all.
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You can also use buck/boost transformers. For 3 phase you need 2 transformers as long as you dont need a neutral line. 2 units on line cost under $300.00 Cheaper than buying all new bulbs.