8pt stock

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8pt stock

Postby donaldwal » Thu Jun 13, 2019 6:22 pm

Anyone ever had an issue with getting a decent KISS impression on 8 point stock screen wise?
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Re: 8pt stock

Postby wdustin1 » Fri Jun 14, 2019 8:07 am

We have run 12 pt stock through a MA2200 and did process work on front and back and didn't have any problems, what kind of issues are you having?
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Re: 8pt stock

Postby Leadpress » Fri Jun 14, 2019 10:20 am

what kind of problem are you having?
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Re: 8pt stock

Postby donaldwal » Sat Jun 15, 2019 5:13 pm

We are printing a label similar to the enclosed photo. The issue I am having is with the top of the dinner plate which is the leading edge of the printing plate. It seems the Magenta and Cyan dots seem to gain during the run and its not gain in the form of enlarging gain as in ink drying on the plate and enlarging the dots. You wipe the plate the print returns to normal for a bit. From my what ive noticed only the leading edge of the plate are printing like this the rest of the image is fine. The printing surface of the image is only a block on a large print cylinder so it has the classic thump as it rotates even with bounce bars. Ive played with the impression endlessly to no avail. The press it is being printed on is a NilPeter Fb 3300 using water based inks. Mind you the enclosed image isn't exactly the same image Im printing the image im printing the top of the dinner plate is the leading edge.... https://www.facebook.com/24480369557005 ... =3&theater
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Re: 8pt stock

Postby Frank Burgos » Sun Jun 16, 2019 8:52 am

Hi donaldwal,

I don't have a definitive answer, but I do have some input:

Often, when I am setting up a press printing with water-based ink, whether wide- or narrow-web, I find that the leading edge builds up, just as you describe. I am so familiar with this and expect it, that it does not affect me as I set up. I don't know why, but it is the leading edge, especially with process dots.

When this happens, and when I am set up and getting ready to pull a sample for approval, I wipe the plates and then I crank up the press to operating speed before going into impression.

There are colleagues of mine that insist on running 4-color process work at the highest speed possible and don't go into impression until they web is at speed.

So, what do these actions point to? Water-based ink not re-wetting. Why on the leading edge? Hell if I know.

Whatever the ultimate solution is, be sure that you carefully control the pH and viscosity of the ink. I find that narrow-web operators tend to have a disadvantage, because so many jobs are run with just "panning" the ink, or not using a pump.

Ink in narrow web stations that are not pumped tend to go up in viscosity and own in pH quickly. I also find that operators often don't appreciate how many challenges uncontrolled inks can cause.

Whatever you do, control the properties. If the problem persists with this job, consider pumping, which is more stable, due to the larger volume of ink, and lends itself to monitoring and adjusting the properties while the press runs.

I have had to come to the rescue of several clients, when all that was wrong was that the operators were not adequately controlling pH and viscosity. I spent one week with a client that prints water-based ink on a 150" press. (correct. a little over 12 feet). I beat those guys up so badly about controling the ink that they hung up a picture of me and splattered ink on it as they worked, as a way of getting back at me for coming up to them every 15-minutes to ask "Y la tinta?" (And, the ink?) I would also say, out loud, "La tinta! La tinta!" They will never forget it and they are now cranking out work on that beast.
Attachments
Mms_2018-11-04_13_33_17.jpg
"La tinta!"
Mms_2018-11-04_13_33_17.jpg (847.95 KiB) Viewed 715 times
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Re: 8pt stock

Postby donaldwal » Mon Jun 17, 2019 2:45 pm

The last run I did pump all colors thinking the ink management would help me greatly considering this is also a sheeted job.... I did talk to our owner and got him to have our artist take the y/m/c out of the leading edge of the dinner plate and go with just a black screen on the dinner plate. The screen black plates leading edge is about 2 inches from the dinner plate and surprisingly enough the black plate was giving me no issues so it was maybe worth a try for next run. I will let you know next month when I run this job again how it goes.... I will post pictures of the comparison . Cheers
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Re: 8pt stock

Postby Frank Burgos » Mon Jun 17, 2019 4:04 pm

Great. Thanks, in advance, for sharing your finding the next time you run. This is good stuff.
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Re: 8pt stock

Postby Buck from N.C. » Mon Jun 24, 2019 6:44 pm

If you have trouble again, get some silicon spray. After cleaning screens, use silicon completes. It keeps the dots clean.
You could also use a little glycol.
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Re: 8pt stock

Postby donaldwal » Wed Jul 24, 2019 8:43 am

Not sure how to post pictures on here but the new plate with the modified dinner plate made with process black plate worked like a charm..... The run went off fantastic!!!!!
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