LED exposure times and diazo emulsions.

[Prosperi-Tees]

About to pull the trigger on one and was wondering how it does with diazo emulsions. Particularly Murakami SP1400, how long are you exposing and how does it hold up to water base discharge? Any post exposing needed? How easy is it to over expose a screen for LED?

Im sure this stuff has been covered but most of the threads are super long and controversial lol.

[Frog]

Can't tell you thing about exposure times, but can assure you that SP 1400 will not benefit from a post exposure. Once developed, Diazo emulsions are done.

[JBLUE]

What Andy says is true. If you do not expose it right the first time its not going to do any good to post expose it. This is true for sp1400. This is what we use.

[Prosperi-Tees]

So what you are telling me is I have to learn how to properly expose a screen...pfft. lol

[jvanick]

About to pull the trigger on one and was wondering how it does with diazo emulsions. Particularly Murakami SP1400, how long are you exposing and how does it hold up to water base discharge? Any post exposing needed? How easy is it to over expose a screen for LED?

We use SP1400 exclusively here now...

Our times on a Starlight:

27 seconds for a 200 mesh 1x1
41 seconds for a 156 mesh 2x1

I *may* be over cooking the 156 a bit, but it still rinses out easilly, and we're getting 7 full steps on a Saati strip.

Funny tho.. when we first got the unit, I cooked a 156 at 1:30, just to see what happens... surprisingly, it still rinsed out just fine.  I don't have a good way to compare undercutting (I do have a microscope, but for whatever reason, I just can't see it...  Maybe I'll give it a shot again when we have a few minutes to spare.   So I can say at least in my opinion/experience, overcooking doesn't seem to matter quite as much as it does with other exposure systems.

As far as waterbase/discharge goes... I did 1200 shirts a few weeks back with Rutland White Plus, and the screen not only held up just fine, but after rinsing it out post run, looked like it could have gone at least another 1200 shirts no problem at all.  I would say no post exposure, but the screens do typically sit in the sun a bit while we're getting ready to tape them, so there *could* be some post exposure happening that I don't know about.

[alan802]

I just put a gallon of the 1400 into production and I was pleasantly surprised by exposure times.  My guy, being a screen tech for a year and a half still doesn't know the difference between dual cure and pure photopolymer so he burned them as if they were the same as the HVP and they were only slightly underexposed.  We added about 20% to our HVP times and they (1400 screens) are all properly exposed.  I can live with that added exposure time since it's only a difference of burning for 30 seconds to 40 seconds.  I just told the guys to make sure we burn 2 at a time instead of getting lazy and only shooting one screen at a time.

[Frog]

I just put a gallon of the 1400 into production and I was pleasantly surprised by exposure times.  My guy, being a screen tech for a year and a half still doesn't know the difference between dual cure and pure photopolymer so he burned them as if they were the same as the HVP and they were only slightly underexposed.  We added about 20% to our HVP times and they (1400 screens) are all properly exposed.  I can live with that added exposure time since it's only a difference of burning for 30 seconds to 40 seconds.  I just told the guys to make sure we burn 2 at a time instead of getting lazy and only shooting one screen at a time.

doesn't know the difference between dual cure and pure photopolymer, or a regular Diazo like SP1400!

[mimosatexas]

Big fan of the 1400 here, but it takes me a good 3 minutes on my 1k MH unit currently

[alan802]

I just put a gallon of the 1400 into production and I was pleasantly surprised by exposure times.  My guy, being a screen tech for a year and a half still doesn't know the difference between dual cure and pure photopolymer so he burned them as if they were the same as the HVP and they were only slightly underexposed.  We added about 20% to our HVP times and they (1400 screens) are all properly exposed.  I can live with that added exposure time since it's only a difference of burning for 30 seconds to 40 seconds.  I just told the guys to make sure we burn 2 at a time instead of getting lazy and only shooting one screen at a time.

doesn't know the difference between dual cure and pure photopolymer, or a regular Diazo like SP1400!

Yeah, that too.

[Homer]

the starlight will cure anything you throw at it...post exposure is not needed if you expose it properly the first time.

we use HXT now and we run WB/DC no problems at all...if you expose it right the first time.

[dirkdiggler]

the starlight will cure anything you throw at it...post exposure is not needed if you expose it properly the first time.

we use HXT now and we run WB/DC no problems at all...if you expose it right the first time.

how long on the starlight with HXT for discharge?

[Gilligan]

Don't forget to log and check for times here so we have one place to look all of this data up.

https://docs.google.com/spreadsheet/ccc?key=0AgdPJ7c6eSh6dFZ4bVBSTFVXZzZ5eFNvX3JyVk9vQ0E&usp=sharing

[Homer]

the starlight will cure anything you throw at it...post exposure is not needed if you expose it properly the first time.

we use HXT now and we run WB/DC no problems at all...if you expose it right the first time.

how long on the starlight with HXT for discharge?

depending on mesh and counts, 35 seconds to 1:00....

were trying to dial in the S meshes now, 180 @ 35 seems about right.