Author Topic: This again.  (Read 4810 times)

Offline ScreenPrinter123

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Re: This again.
« Reply #30 on: April 02, 2015, 04:02:55 PM »
This is likely the major difference between your flash times. Wattage as well, but having the bulbs pre-heated
make a big difference. We run no standby, as once the pallets are warm flashing takes less time than printing.
Saves energy in my mind, but I could be wrong due to the increased power required to heat a bulb from zero.

Maybe you could lower the power during actual flash and run a standby and let us know the difference with an amp meter and some simple calculations...yes I just volunteered you.  :o


Offline jvanick

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Re: This again.
« Reply #31 on: April 02, 2015, 04:10:07 PM »
We have a Red Chili D 2024 on our sportsman, and after the first shirts start going under the flash, for a typical Gildan Ultra shirt, the flash time ends up around 4-4.5 seconds (with the temperature sensor set at 200 degrees F) the bulbs are 2.25" above the platen when the table is up.

Ink is quick white, non modified... platens cold.  once the platens warm up, the flash time gets even lower... 

-- this is one reason I really like the 'D' model of this flash, you can watch the bulbs and decrease the flash time on the press's control panel as you go to index even faster.

Offline blue moon

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Re: This again.
« Reply #32 on: April 02, 2015, 04:51:26 PM »
I think this was mentioned already, I lose track as I get older . . . Anytime I had this problem (few years back when I was still printing), it was too much heat. drop your flash times, make sure the ink cools down before printing on it. Slow your flood to a crawl and put a fan on the platen so it blows on it between the shirt and the screen during the flood. Measure your deposit temperature and see what's going on. You also mentioned flashing again, so it all points towards too much heat and cooking the ink in the screens.

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!

Offline ZooCity

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Re: This again.
« Reply #33 on: April 03, 2015, 01:51:13 PM »
We're actually at ≈2.5-2.75" from the bulb to platen when tabled up, sorry I had that wrong.

Flash times or intensity drop after the run gets going, seems to still be something needed despite preheating. 

Nearly everything we print requires a more gentle flash.  We do run some regular, c.o.e. cotton Ts like G2000s and the like but it's ringspun all day most days with lots of blends and also mixed items on runs.  We've found that in most cases a longer flash at lower intensity is best.  We do have very fast flashes at times but it's the exception v. the norm. 

I think slower is better for gelling plastisol.  I have the crew flash hotter/faster only if the flash is slowing down the run.  I don't have good empirical data to back that up or anything.