Question for CTS users #24

[TCT]

See what I did with the title there? Ya, made myself a little joke in the title..... Sorry, it has been that kind of a day

Anyway, I did have 2 actual questions for CTS users-

1) CTS is awesome, no reg marks right? How about sim process jobs? Do you throw some on those screens?

2) I assume and have seen CTS units in environmentally controlled screen rooms. Is there ever a concern/issue/warning about having the unit too close to a dehumidifier?

[Dottonedan]

If I may reply as an installer:

The questions posed seems to imply you are referring to a CTS using a registration system matched on press like the Tri-Loc. As far as I am aware, (and could be wrong), but not all CTS are set up this way but I'm sure could be adapted.

When I install, I want the customer to give me their toughest job.  As many colors they can print or can be cmyk or sim process. No reggies. I let their operator load all screens. 99.9% of the time, the worse case scenario will be that 2 out of 6-12 colors might need tweaked on the micro. If there is something out of register that is obvious, it's due to something in the art or the loading/setting the screen in the device that might be crooked or not pulled back in all the way and was not caught. I've never seen a CTS physically print out of register.

The proximity of the dehumidifier should be calculated. It's relative, no pun intended. Some shops have their coating and screen drying area in the same room as the machine creating a constant fight. It can be in the same room, but I always suggest to set up a meet locker type divider to help maintain consistency for the machine. While we do suggest to have the machine in a consistently controlled area, some customers just don't prefer to do that. I've seen these machines in a few rooms of 80% humidity and 110 degrees down to 20% humidity and 40 degrees and they still operate fine. How fine, for how long remains t be seen. These machines have computers and software needed to run. Think of putting your work computer in 80% humidity for a long period of time. Condensation can build up and corrode electrical systems etc. It can run fine for a while, but the manufacturers don't recommend it.  Some shops with large rooms have added as many as three dehumidifiers capable of going up or down that also can tell you what the RH is the area that it is in. Just one in a large room might not be enough.

It's a fact that extreme degrees of temperature and humidity does affect the image output as well. This ink sprays out in a fine spit or spray (I think) about 7-15 picoliter sized sprays for most wet ink cts. If too dry,as it leaves the head to be transferred to the screen, it can come out of the head too fine or light causing slightly fuzzy line art and dots, if too wet, it may come out too heavy, too fast, causing excessive gain and ink usage. It requires a balance within reason.

[jvanick]

I'll add to dan's response:

we haven't printed ANY reg marks since we started... and I agree with what he said 2-3 screens will *sometimes* need adjustments... we've set up 4 and 5 colors jobs that have needed none, and we've setup a few other jobs that needed all except for the underbase (in hindsight, we probably should have adjusted the underbase first on those)...

as far as conditions go...

our epson based i-image (which a LOT of users here have had issues with) still has all 10 channels in perfect condition, and prints beautifully every time, lives in our screen room which is temperature controlled from 74-85 degrees, 18-40% RH.  (I can provide graphs that show/prove those levels). 

I think if you had the wild temperature swings, and/or wild humidity swings you may have issues... but since we control things so tightly we don't have issues.

[TCT]

OK so my first question now seems stupid, so let's drop that in efforts for me to save face....
Dehumidifier question, a constant lower 30's% humidity and mid 70's for temp won't pose a issue? Even if the unit is like 5' from a dehumidifier?

[jvanick]

our's is about 10 feet from the dehumidifier... no issues.

actually I think it's probably better as the swings will be lower closer to it.

[Dottonedan]

actually I think it's probably better as the swings will be lower closer to it.

Agreed. Actually, that 30% humidity and 70 degrees is a good range. 40% might be best, but yes.

[GraphicDisorder]

1. No reg marks, ever here.
2. Ours is located aproximately 12ft from our gas dryer right in our screen printing area. This room is NOT climate controlled other than its kept at least 50 in the winter on nights/weekends. It's easily 100-110 in the summer in there...... we've had not the first issue with our i-Image ST.

[Doug S]

I have the epson based i image.  It's located in my drying/coating/developing and reclaim room.  I do have a partition between the reclaim and the i image.  The room is climate controlled.  The RH never gets above 60 but most of the time stays at around 45 to 50.  I've only had to do one power cleaning in the year and 1/2 I've had it but all of my nozzles are working. 

I started out printing reg marks on sim and 4 cp jobs but stopped because I didn't need them.  All they were doing is giving me more to tape up.   I mean if it's out of reg it is so minor that a guess is all you need to fix it but after a tip from ole Jvanick to squeeze the triloc against the frame while locking it in, I'm rarely out of reg at all.   In fact, this week going through 25 or so jobs, I had to micro maybe 2 screens.  I told my wife that if the cts ever quits, it's time to buy another or quit.  I'm spoiled.

[GKitson]

We are wax based so I will ignore the RH aspect of the original question.

No registration marks ever.  We are 100% Newman pin registered and a lot of jobs run with no micro.

However we put a t-line on the bottom of every job with Design # info and a center point based on customer approval, this make non traditional print locations easier.

ALL 4/c process get color balance bars, gotta have the neutral gray, but no registration marks, ever.

~Kitson